diff --git a/.changeset/preserve-gh-aw-builtins.md b/.changeset/preserve-gh-aw-builtins.md
new file mode 100644
index 000000000..8288efad0
--- /dev/null
+++ b/.changeset/preserve-gh-aw-builtins.md
@@ -0,0 +1,12 @@
+---
+"@bradygaster/squad-cli": patch
+"@bradygaster/squad-sdk": patch
+---
+
+Standardize the Rai built-in agent on the canonical lowercase directory/template ID `rai` (matching `scribe`, `ralph`, and `fact-checker`) instead of the mixed-case `Rai`, which broke on case-sensitive filesystems (Linux CI) and silently duplicated the agent on case-insensitive ones (macOS/Windows).
+
+`squad upgrade` now detects a legacy case-sensitive `.squad/agents/Rai/` directory and migrates it in place to `.squad/agents/rai/`, preserving the existing charter/history content. If both `Rai/` and `rai/` already exist (a partial upgrade on a case-sensitive filesystem), the canonical `rai/` is kept untouched and only the stale `Rai/` copy is removed — no user customization is ever clobbered, and repeat upgrade runs are idempotent.
+
+The shipped Rai charter template's manifest source/destination were also renamed from `Rai-charter.md` to lowercase `rai-charter.md`, matching the file already shipped under `templates/`.
+
+The `workflows/squad.md` gh-aw coordinator prompt and its paired `squad-cast-validator.mjs` validator now let the generated coordinator name the four permanent built-in support agents (Scribe, Ralph, Rai, Fact Checker) and state their fixed lifecycle duties in a dedicated `## Built-in Support Agents` section, while still forbidding any reference to unrelated standalone lifecycle/log/decision state or paths.
diff --git a/.squad-templates/fact-checker-charter.md b/.squad-templates/fact-checker-charter.md
index 1d03e0b4e..88b89517c 100644
--- a/.squad-templates/fact-checker-charter.md
+++ b/.squad-templates/fact-checker-charter.md
@@ -7,7 +7,7 @@
 - **Name:** Fact Checker
 - **Role:** Devil's Advocate & Verification Agent
 - **Style:** Rigorous but constructive. Flags issues clearly without being abrasive.
-- **Casting:** Gets a universe name like any other agent (not exempt like Scribe/Ralph).
+- **Casting:** Permanently exempt from casting/universe naming alongside Scribe, Ralph, and Rai; fixed ID `fact-checker`.
 
 ## What I Do
 
diff --git a/.squad-templates/rai-charter.md b/.squad-templates/rai-charter.md
index 921a999a3..d774ae663 100644
--- a/.squad-templates/rai-charter.md
+++ b/.squad-templates/rai-charter.md
@@ -14,7 +14,7 @@
 
 - `.squad/rai/policy.md` — Canonical RAI policy (terms, anti-patterns, taxonomy)
 - `.squad/rai/audit-trail.md` — Evidence log (append-only, redacted)
-- `.squad/agents/Rai/history.md` — Learnings across sessions
+- `.squad/agents/rai/history.md` — Learnings across sessions
 
 ## Traffic Light Verdicts
 
diff --git a/.squad-templates/ralph-charter.md b/.squad-templates/ralph-charter.md
new file mode 100644
index 000000000..9a1959832
--- /dev/null
+++ b/.squad-templates/ralph-charter.md
@@ -0,0 +1,52 @@
+# Ralph
+
+> Keeps the board moving until it is actually clear.
+
+## Identity
+
+- **Name:** Ralph
+- **Role:** Work Monitor
+- **Style:** Persistent, concise, operational.
+- **Mode:** Active on request ("Ralph, go") or idle-watch by default. Never blocks the conversation.
+
+## What I Own
+
+- Scanning for open Squad work: `squad:*` labels, draft PRs, review feedback, CI failures, merge-ready PRs.
+- Driving the work queue while active — scan, act, rescan, repeat.
+- Reporting compact board status.
+
+## How I Work
+
+**Philosophy:** don't pause for permission between work items while active — keep looping until the
+board is clear or the user explicitly says idle/stop. A clear board moves me to idle-watch, not full
+shutdown.
+
+1. **Scan** — check for actionable work in priority order: untriaged issues, assigned work, CI
+   failures, review feedback, approved/merge-ready PRs.
+2. **Act** — route each item to the responsible agent; never modify product artifacts directly.
+3. **Rescan** — after work lands, check again immediately. Do not wait for the user to ask.
+4. **Report** — compact board status only. No narration, no filler.
+
+Use the `gh` CLI when GitHub MCP tooling is unavailable.
+
+## Board Status Format
+
+```
+📋 Board: {N} open | {M} in review | {K} merge-ready
+```
+
+## Boundaries
+
+**I handle:** Work discovery, board status, issue/PR monitoring, keep-working loops.
+
+**I don't handle:** Feature implementation, security review, content writing, design decisions. I
+route work — I don't do it.
+
+## Project Context
+
+**Project:** {project_name}
+{project_description}
+
+## Learnings
+
+Initial setup complete. Ready to monitor the board.
diff --git a/packages/squad-cli/src/cli/core/cast.ts b/packages/squad-cli/src/cli/core/cast.ts
index b98163e31..4246094f9 100644
--- a/packages/squad-cli/src/cli/core/cast.ts
+++ b/packages/squad-cli/src/cli/core/cast.ts
@@ -404,7 +404,7 @@ function generateCharter(member: CastMember & { _personality?: string; _backstor
   if (catalogCharter) return catalogCharter;
 
   const personality = personalityForRole(member.role, { personality: member._personality });
-  const nameLower = member.name.toLowerCase();
+  const nameLower = memberId(member.name);
 
   // If CastingEngine provided a backstory, use it in the charter preamble
   const preamble = member._backstory || personality;
@@ -477,6 +477,24 @@ function generateHistory(member: CastMember, projectDescription: string): string
 
 // ── Built-in agents ────────────────────────────────────────────────
 
+// The four built-in support agents always materialize under these exact
+// lowercase kebab-case directory/registry IDs, regardless of display-name
+// casing or spacing (`member.name.toLowerCase()` alone turns "Fact Checker"
+// into "fact checker" — a space, not a hyphen — and leaves "Rai" ambiguous
+// against other built-in scaffolders). Canonical built-in contract: scribe,
+// ralph, rai, fact-checker.
+const BUILTIN_IDS: Record<string, string> = {
+  'Scribe': 'scribe',
+  'Ralph': 'ralph',
+  'Rai': 'rai',
+  'Fact Checker': 'fact-checker',
+};
+
+/** Resolve a member's directory/registry ID: the authoritative built-in ID when the name is one of the four built-ins, otherwise the existing lowercased-name behavior for specialists. */
+function memberId(name: string): string {
+  return BUILTIN_IDS[name] ?? name.toLowerCase();
+}
+
 function scribeMember(): CastMember {
   return { name: 'Scribe', role: 'Session Logger', scope: 'Maintaining decisions.md, cross-agent context sharing, orchestration logging, session logging, git commits', emoji: '📋' };
 }
@@ -592,7 +610,7 @@ function RaiCharter(): string {
 
 - \`.squad/rai/policy.md\` — Canonical RAI policy (terms, anti-patterns, taxonomy)
 - \`.squad/rai/audit-trail.md\` — Evidence log (append-only, redacted)
-- \`.squad/agents/Rai/history.md\` — Learnings across sessions
+- \`.squad/agents/rai/history.md\` — Learnings across sessions
 
 ## Traffic Light Verdicts
 
@@ -640,7 +658,7 @@ Before starting work, run \`git rev-parse --show-toplevel\` to find the repo roo
 
 Read \`.squad/rai/policy.md\` for the canonical check definitions.
 Append findings to \`.squad/rai/audit-trail.md\` (redacted — never raw secrets or harmful text).
-After making a decision others should know, write it to \`.squad/decisions/inbox/Rai-{brief-slug}.md\`.
+After making a decision others should know, write it to \`.squad/decisions/inbox/rai-{brief-slug}.md\`.
 `;
 }
 
@@ -649,7 +667,7 @@ After making a decision others should know, write it to \`.squad/decisions/inbox
 function buildMembersTable(allMembers: CastMember[]): string {
   let table = `## Members\n\n| Name | Role | Charter | Status |\n|------|------|---------|--------|\n`;
   for (const m of allMembers) {
-    const nameLower = m.name.toLowerCase();
+    const nameLower = memberId(m.name);
     let status = '✅ Active';
     if (m.role === 'Session Logger') status = '📋 Silent';
     if (m.role === 'Work Monitor') status = '🔄 Monitor';
@@ -700,7 +718,7 @@ export async function createTeam(teamRoot: string, proposal: CastProposal): Prom
 
   // Create agent directories and files
   for (const member of allMembers) {
-    const nameLower = member.name.toLowerCase();
+    const nameLower = memberId(member.name);
     const agentDir = join(agentsDir, nameLower);
 
     const charterPath = join(agentDir, 'charter.md');
@@ -805,7 +823,7 @@ export async function createTeam(teamRoot: string, proposal: CastProposal): Prom
   const registryAgents: Record<string, object> = {};
   const snapshotAgents: string[] = [];
   for (const member of allMembers) {
-    const nameLower = member.name.toLowerCase();
+    const nameLower = memberId(member.name);
     registryAgents[nameLower] = {
       created_at: now,
       persistent_name: member.name,
@@ -853,7 +871,7 @@ export async function createTeam(teamRoot: string, proposal: CastProposal): Prom
 
   // Sync new agents into squad.config.ts (if present)
   for (const member of allMembers) {
-    await addAgentToConfig(teamRoot, member.name.toLowerCase(), member.role);
+    await addAgentToConfig(teamRoot, memberId(member.name), member.role);
   }
 
   // Re-advertise the cast in .github/agents/squad.agent.md (#1608). Cast
diff --git a/packages/squad-cli/src/cli/core/templates.ts b/packages/squad-cli/src/cli/core/templates.ts
index 469698a60..96f398bf5 100644
--- a/packages/squad-cli/src/cli/core/templates.ts
+++ b/packages/squad-cli/src/cli/core/templates.ts
@@ -136,8 +136,8 @@ export const TEMPLATE_MANIFEST: TemplateFile[] = [
     description: 'Scribe charter template',
   },
   {
-    source: 'Rai-charter.md',
-    destination: 'templates/Rai-charter.md',
+    source: 'rai-charter.md',
+    destination: 'templates/rai-charter.md',
     overwriteOnUpgrade: true,
     description: 'Rai RAI reviewer charter template',
   },
diff --git a/packages/squad-cli/src/cli/core/upgrade.ts b/packages/squad-cli/src/cli/core/upgrade.ts
index 68931972d..bde8cc82a 100644
--- a/packages/squad-cli/src/cli/core/upgrade.ts
+++ b/packages/squad-cli/src/cli/core/upgrade.ts
@@ -879,6 +879,15 @@ async function runEnsureChecks(dest: string, templatesDir: string, filesUpdated:
     filesUpdated.push(...memoryFiles);
   }
 
+  const raiMigration = migrateLegacyRaiAgent(dest);
+  if (raiMigration.migrated.length > 0) {
+    success('migrated .squad/agents/Rai/ → .squad/agents/rai/');
+    filesUpdated.push(...raiMigration.migrated);
+  }
+  if (raiMigration.tombstoned.length > 0) {
+    success('removed stale .squad/agents/Rai/ (superseded by .squad/agents/rai/)');
+  }
+
   const builtinAgents = ensureBuiltinAgents(dest, templatesDir);
   if (builtinAgents.length > 0) {
     const uniqueAgentNames = Array.from(new Set(builtinAgents.map(p => path.basename(path.dirname(p)))));
@@ -997,6 +1006,66 @@ export function ensureMemoryGovernanceUpgradeDefaults(dest: string): string[] {
   return created;
 }
 
+/**
+ * Migrate the legacy case-sensitive `.squad/agents/Rai/` directory — produced
+ * by prior releases that scaffolded the built-in with a capitalized directory
+ * name — to the canonical lowercase `.squad/agents/rai/`, preserving any
+ * existing charter/history content.
+ *
+ * Detection uses `storage.listSync` (on-disk entry names) rather than
+ * `storage.existsSync('.squad/agents/rai')`, because `existsSync` can report
+ * a false positive for `rai` on case-insensitive filesystems (macOS, Windows)
+ * even when only the legacy `Rai` entry physically exists — that false
+ * positive would make the migration silently no-op on those platforms and
+ * leave the case-sensitive `.squad/agents/Rai/` behind on Linux checkouts of
+ * the same repo.
+ *
+ * Idempotent and duplicate-safe:
+ *  - Only `Rai/` exists → rename it in place to `rai/` (single `renameSync`,
+ *    same convention as `migrateDirectory`'s `.ai-team/` → `.squad/` rename).
+ *  - Both `Rai/` and `rai/` exist (possible on a case-sensitive filesystem
+ *    after a partial upgrade) → canonical `rai/` wins; the legacy `Rai/` is
+ *    removed without overwriting `rai/`, so no in-place customization at the
+ *    canonical location is ever clobbered.
+ *  - Neither exists, or only `rai/` exists → no-op.
+ *
+ * @param dest Root directory containing .squad/
+ * @returns Paths (relative to dest) affected by the migration
+ */
+export function migrateLegacyRaiAgent(dest: string): { migrated: string[]; tombstoned: string[] } {
+  const agentsDir = path.join(dest, '.squad', 'agents');
+  if (!storage.existsSync(agentsDir)) return { migrated: [], tombstoned: [] };
+
+  const entries = storage.listSync(agentsDir);
+  const legacyDir = path.join(agentsDir, 'Rai');
+  if (!entries.includes('Rai') || !storage.isDirectorySync(legacyDir)) {
+    return { migrated: [], tombstoned: [] };
+  }
+
+  const canonicalDir = path.join(agentsDir, 'rai');
+  const migrated: string[] = [];
+  const tombstoned: string[] = [];
+
+  if (entries.includes('rai')) {
+    // Both exist — canonical `rai/` wins, drop the legacy copy as-is.
+    try {
+      storage.deleteDirSync(legacyDir);
+      tombstoned.push(path.posix.join('.squad/agents', 'Rai'));
+    } catch {
+      // best-effort; leave the legacy dir if we can't remove it
+    }
+    return { migrated, tombstoned };
+  }
+
+  try {
+    storage.renameSync(legacyDir, canonicalDir);
+    migrated.push(path.posix.join('.squad/agents', 'rai'));
+  } catch {
+    // best-effort; leave the legacy dir if the rename fails (e.g. read-only fs)
+  }
+  return { migrated, tombstoned };
+}
+
 /**
  * Scaffold always-on built-in agent charters (Rai, Fact Checker) that ship
  * as templates but may be missing from older squads. Idempotent — only writes
@@ -1009,6 +1078,11 @@ export function ensureMemoryGovernanceUpgradeDefaults(dest: string): string[] {
  * cast.ts (no shipped template file). Adding them here would risk overwriting
  * customized versions on legacy squads.
  *
+ * Callers should run `migrateLegacyRaiAgent(dest)` before this function so a
+ * pre-existing legacy `.squad/agents/Rai/` is renamed to `rai/` first — this
+ * function's idempotency check (`storage.existsSync(agentDir)`) would
+ * otherwise miss it on case-sensitive filesystems and scaffold a duplicate.
+ *
  * @param dest Root directory containing .squad/
  * @param templatesDir Directory containing shipped charter templates
  * @returns Paths (relative to dest) of created agent files
@@ -1023,8 +1097,14 @@ export function ensureBuiltinAgents(dest: string, templatesDir: string): string[
   //   - dirName: case-preserving directory name under .squad/agents/
   //   - templateFile: filename under templatesDir (charter template)
   //   - displayName: shown in history.md header
+  //
+  // dirName/templateFile use the authoritative lowercase kebab-case built-in
+  // ID (`rai`, not `Rai`) so this matches the canonical `.squad-templates/`
+  // charter filenames and the directory IDs every other built-in scaffolder
+  // (cast.ts's `memberId()`) now produces. Canonical built-in contract:
+  // scribe, ralph, rai, fact-checker.
   const builtins: Array<{ dirName: string; templateFile: string; displayName: string }> = [
-    { dirName: 'Rai', templateFile: 'Rai-charter.md', displayName: 'Rai' },
+    { dirName: 'rai', templateFile: 'rai-charter.md', displayName: 'Rai' },
     { dirName: 'fact-checker', templateFile: 'fact-checker-charter.md', displayName: 'Fact Checker' },
   ];
 
diff --git a/packages/squad-cli/templates/fact-checker-charter.md b/packages/squad-cli/templates/fact-checker-charter.md
index 1d03e0b4e..88b89517c 100644
--- a/packages/squad-cli/templates/fact-checker-charter.md
+++ b/packages/squad-cli/templates/fact-checker-charter.md
@@ -7,7 +7,7 @@
 - **Name:** Fact Checker
 - **Role:** Devil's Advocate & Verification Agent
 - **Style:** Rigorous but constructive. Flags issues clearly without being abrasive.
-- **Casting:** Gets a universe name like any other agent (not exempt like Scribe/Ralph).
+- **Casting:** Permanently exempt from casting/universe naming alongside Scribe, Ralph, and Rai; fixed ID `fact-checker`.
 
 ## What I Do
 
diff --git a/packages/squad-cli/templates/rai-charter.md b/packages/squad-cli/templates/rai-charter.md
index 921a999a3..d774ae663 100644
--- a/packages/squad-cli/templates/rai-charter.md
+++ b/packages/squad-cli/templates/rai-charter.md
@@ -14,7 +14,7 @@
 
 - `.squad/rai/policy.md` — Canonical RAI policy (terms, anti-patterns, taxonomy)
 - `.squad/rai/audit-trail.md` — Evidence log (append-only, redacted)
-- `.squad/agents/Rai/history.md` — Learnings across sessions
+- `.squad/agents/rai/history.md` — Learnings across sessions
 
 ## Traffic Light Verdicts
 
diff --git a/packages/squad-cli/templates/ralph-charter.md b/packages/squad-cli/templates/ralph-charter.md
new file mode 100644
index 000000000..9a1959832
--- /dev/null
+++ b/packages/squad-cli/templates/ralph-charter.md
@@ -0,0 +1,52 @@
+# Ralph
+
+> Keeps the board moving until it is actually clear.
+
+## Identity
+
+- **Name:** Ralph
+- **Role:** Work Monitor
+- **Style:** Persistent, concise, operational.
+- **Mode:** Active on request ("Ralph, go") or idle-watch by default. Never blocks the conversation.
+
+## What I Own
+
+- Scanning for open Squad work: `squad:*` labels, draft PRs, review feedback, CI failures, merge-ready PRs.
+- Driving the work queue while active — scan, act, rescan, repeat.
+- Reporting compact board status.
+
+## How I Work
+
+**Philosophy:** don't pause for permission between work items while active — keep looping until the
+board is clear or the user explicitly says idle/stop. A clear board moves me to idle-watch, not full
+shutdown.
+
+1. **Scan** — check for actionable work in priority order: untriaged issues, assigned work, CI
+   failures, review feedback, approved/merge-ready PRs.
+2. **Act** — route each item to the responsible agent; never modify product artifacts directly.
+3. **Rescan** — after work lands, check again immediately. Do not wait for the user to ask.
+4. **Report** — compact board status only. No narration, no filler.
+
+Use the `gh` CLI when GitHub MCP tooling is unavailable.
+
+## Board Status Format
+
+```
+📋 Board: {N} open | {M} in review | {K} merge-ready
+```
+
+## Boundaries
+
+**I handle:** Work discovery, board status, issue/PR monitoring, keep-working loops.
+
+**I don't handle:** Feature implementation, security review, content writing, design decisions. I
+route work — I don't do it.
+
+## Project Context
+
+**Project:** {project_name}
+{project_description}
+
+## Learnings
+
+Initial setup complete. Ready to monitor the board.
diff --git a/packages/squad-sdk/templates/fact-checker-charter.md b/packages/squad-sdk/templates/fact-checker-charter.md
index 1d03e0b4e..88b89517c 100644
--- a/packages/squad-sdk/templates/fact-checker-charter.md
+++ b/packages/squad-sdk/templates/fact-checker-charter.md
@@ -7,7 +7,7 @@
 - **Name:** Fact Checker
 - **Role:** Devil's Advocate & Verification Agent
 - **Style:** Rigorous but constructive. Flags issues clearly without being abrasive.
-- **Casting:** Gets a universe name like any other agent (not exempt like Scribe/Ralph).
+- **Casting:** Permanently exempt from casting/universe naming alongside Scribe, Ralph, and Rai; fixed ID `fact-checker`.
 
 ## What I Do
 
diff --git a/packages/squad-sdk/templates/rai-charter.md b/packages/squad-sdk/templates/rai-charter.md
index 921a999a3..d774ae663 100644
--- a/packages/squad-sdk/templates/rai-charter.md
+++ b/packages/squad-sdk/templates/rai-charter.md
@@ -14,7 +14,7 @@
 
 - `.squad/rai/policy.md` — Canonical RAI policy (terms, anti-patterns, taxonomy)
 - `.squad/rai/audit-trail.md` — Evidence log (append-only, redacted)
-- `.squad/agents/Rai/history.md` — Learnings across sessions
+- `.squad/agents/rai/history.md` — Learnings across sessions
 
 ## Traffic Light Verdicts
 
diff --git a/packages/squad-sdk/templates/ralph-charter.md b/packages/squad-sdk/templates/ralph-charter.md
new file mode 100644
index 000000000..9a1959832
--- /dev/null
+++ b/packages/squad-sdk/templates/ralph-charter.md
@@ -0,0 +1,52 @@
+# Ralph
+
+> Keeps the board moving until it is actually clear.
+
+## Identity
+
+- **Name:** Ralph
+- **Role:** Work Monitor
+- **Style:** Persistent, concise, operational.
+- **Mode:** Active on request ("Ralph, go") or idle-watch by default. Never blocks the conversation.
+
+## What I Own
+
+- Scanning for open Squad work: `squad:*` labels, draft PRs, review feedback, CI failures, merge-ready PRs.
+- Driving the work queue while active — scan, act, rescan, repeat.
+- Reporting compact board status.
+
+## How I Work
+
+**Philosophy:** don't pause for permission between work items while active — keep looping until the
+board is clear or the user explicitly says idle/stop. A clear board moves me to idle-watch, not full
+shutdown.
+
+1. **Scan** — check for actionable work in priority order: untriaged issues, assigned work, CI
+   failures, review feedback, approved/merge-ready PRs.
+2. **Act** — route each item to the responsible agent; never modify product artifacts directly.
+3. **Rescan** — after work lands, check again immediately. Do not wait for the user to ask.
+4. **Report** — compact board status only. No narration, no filler.
+
+Use the `gh` CLI when GitHub MCP tooling is unavailable.
+
+## Board Status Format
+
+```
+📋 Board: {N} open | {M} in review | {K} merge-ready
+```
+
+## Boundaries
+
+**I handle:** Work discovery, board status, issue/PR monitoring, keep-working loops.
+
+**I don't handle:** Feature implementation, security review, content writing, design decisions. I
+route work — I don't do it.
+
+## Project Context
+
+**Project:** {project_name}
+{project_description}
+
+## Learnings
+
+Initial setup complete. Ready to monitor the board.
diff --git a/scripts/validate-gh-aw-cast.mjs b/scripts/validate-gh-aw-cast.mjs
index f8b5df932..aea594a72 100644
--- a/scripts/validate-gh-aw-cast.mjs
+++ b/scripts/validate-gh-aw-cast.mjs
@@ -19,7 +19,22 @@ const CORE_PAYLOAD = [
   'meet-the-squad.md',
 ];
 
-const SUPPORT_ROLE_PATTERN = /\b(?:Scribe|Ralph|Rai|RAI|Fact Checker)\b/i;
+// The four built-in support agents are permanent, non-configurable, and
+// always present in a GH-AW Cast, separate from selected Cast specialists.
+// There is no mechanism to add, remove, or rename members of this set.
+const REQUIRED_BUILTIN_IDS = ['fact-checker', 'ralph', 'rai', 'scribe'];
+const BUILTIN_DISPLAY_NAMES = {
+  scribe: 'Scribe',
+  ralph: 'Ralph',
+  rai: 'Rai',
+  'fact-checker': 'Fact Checker',
+};
+const REQUIRED_BUILTIN_CHARTERS = REQUIRED_BUILTIN_IDS
+  .map((id) => `.squad/agents/${id}/charter.md`)
+  .sort();
+const BUILTIN_SECTION_HEADING = '## Built-in Support Agents';
+const CAST_SOURCES_HEADING = '## Cast sources';
+const BUILTIN_NAME_ROW_PATTERN = /^\|\s*(Scribe|Ralph|Rai|Fact Checker)\s*\|/gmi;
 const PLACEHOLDER_PATTERN = /\b(?:pending|uncast)\b|(?:specialists|taskTypes|hints)=0\b/i;
 const FORBIDDEN_REFERENCE_PATTERNS = [
   ['standalone template', /^\.squad\/templates\//],
@@ -30,6 +45,7 @@ const FORBIDDEN_REFERENCE_PATTERNS = [
 const BARE_INTERNAL_PATH_PATTERN =
   /(?:^|[\s`"'(])((?:packages\/[^/\s`"')]+\/src|src\/(?:agents|casting|cli|client|config|coordinator|hooks|runtime|tools))\/[^\s`"')]+)/gm;
 
+
 function parseArgs(argv) {
   const args = new Map();
   for (let index = 0; index < argv.length; index += 2) {
@@ -101,6 +117,31 @@ function extractLocalReferences(markdown) {
   return [...new Set(references)];
 }
 
+/**
+ * Extract the body of a single `## Heading` section (up to the next `##`
+ * heading or end of document). Requires the heading to appear exactly once;
+ * returns null and records an error otherwise.
+ */
+function extractSingleSection(markdown, heading, sourceLabel, errors) {
+  const headingRe = new RegExp(`^${heading.replace(/[.*+?^${}()|[\]\\]/g, '\\$&')}\\s*$`, 'gm');
+  const matches = markdown.match(headingRe) ?? [];
+  if (matches.length !== 1) {
+    errors.push(`${sourceLabel}: expected exactly one "${heading}" heading, found ${matches.length}`);
+    return null;
+  }
+  const idx = markdown.search(headingRe);
+  const afterHeadingLine = markdown.slice(idx + markdown.slice(idx).indexOf('\n') + 1);
+  const nextHeadingIdx = afterHeadingLine.search(/^##\s/m);
+  return nextHeadingIdx === -1 ? afterHeadingLine : afterHeadingLine.slice(0, nextHeadingIdx);
+}
+
+/** Charter-path references (`.squad/agents/{id}/charter.md`) found in a markdown fragment. */
+function charterReferences(markdown) {
+  return extractLocalReferences(markdown)
+    .filter((reference) => /^\.squad\/agents\/[^/]+\/charter\.md$/.test(reference))
+    .sort();
+}
+
 function parseRouting(routing, activeNames, errors) {
   const headingMatches = routing.match(/^## Routing Table\s*$/gm) ?? [];
   if (headingMatches.length !== 1) {
@@ -172,6 +213,9 @@ function parseRegistry(root, errors) {
     if (!/^[a-z0-9][a-z0-9-]*$/.test(member.id) || typeof member.name !== 'string' || !member.name.trim()) {
       errors.push(`registry: invalid active member ${JSON.stringify(member)}`);
     }
+    if (REQUIRED_BUILTIN_IDS.includes(member.id)) {
+      errors.push(`registry: built-in id "${member.id}" must not be an active specialist registry entry`);
+    }
   }
   return active;
 }
@@ -210,6 +254,11 @@ function validateCapabilities(coordinator, active, routingRows, errors) {
   if (PLACEHOLDER_PATTERN.test(block)) {
     errors.push('coordinator: pending, uncast, or zero capability markers are forbidden');
   }
+  for (const [id, displayName] of Object.entries(BUILTIN_DISPLAY_NAMES)) {
+    if (new RegExp(`\\b${displayName}\\b`, 'i').test(block)) {
+      errors.push(`coordinator: capability block must not list built-in "${id}" as a specialist`);
+    }
+  }
   for (const member of active) {
     if (!block.includes(member.name)) {
       errors.push(`coordinator: capability block omits active member "${member.name}"`);
@@ -254,7 +303,7 @@ export function validateCastTree({ root, payloadPath }) {
   const active = parseRegistry(root, errors);
   const activeNames = new Set(active.map(({ name }) => name));
   const activeCharters = active.map(({ id }) => `.squad/agents/${id}/charter.md`);
-  const expectedPayload = new Set([...CORE_PAYLOAD, ...activeCharters]);
+  const expectedPayload = new Set([...CORE_PAYLOAD, ...activeCharters, ...REQUIRED_BUILTIN_CHARTERS]);
   for (const path of payload) {
     if (!expectedPayload.has(path)) errors.push(`payload: unexpected path ${path}`);
   }
@@ -275,10 +324,11 @@ export function validateCastTree({ root, payloadPath }) {
       .filter((entry) => statSync(join(agentsPath, entry)).isDirectory())
       .sort();
     const activeIds = active.map(({ id }) => id).sort();
-    if (JSON.stringify(materializedIds) !== JSON.stringify(activeIds)) {
+    const expectedIds = [...new Set([...activeIds, ...REQUIRED_BUILTIN_IDS])].sort();
+    if (JSON.stringify(materializedIds) !== JSON.stringify(expectedIds)) {
       errors.push(
-        `tree: materialized agent directories must exactly match active registry IDs `
-        + `(expected ${activeIds.join(', ')}, found ${materializedIds.join(', ')})`,
+        `tree: materialized agent directories must exactly match active registry IDs plus the `
+        + `four required built-ins (expected ${expectedIds.join(', ')}, found ${materializedIds.join(', ')})`,
       );
     }
   }
@@ -295,22 +345,51 @@ export function validateCastTree({ root, payloadPath }) {
     return errors;
   }
 
-  if (SUPPORT_ROLE_PATTERN.test(team)) {
-    errors.push('team: inactive/support roles must not be advertised by the GH-AW Cast roster');
+  const teamCharters = charterReferences(team);
+  const expectedTeamCharters = [...new Set([...activeCharters, ...REQUIRED_BUILTIN_CHARTERS])].sort();
+  if (JSON.stringify(teamCharters) !== JSON.stringify(expectedTeamCharters)) {
+    errors.push(
+      `team: charter references must exactly match active specialists plus the four required `
+      + `built-ins (expected ${expectedTeamCharters.join(', ')}, found ${teamCharters.join(', ')})`,
+    );
   }
-  if (SUPPORT_ROLE_PATTERN.test(coordinator)) {
-    errors.push('coordinator: inactive/support roles are forbidden in GH-AW Cast output');
+
+  const membersSection = extractSingleSection(team, '## Members', 'team', errors);
+  if (membersSection !== null) {
+    const leakedBuiltinCharters = charterReferences(membersSection)
+      .filter((reference) => REQUIRED_BUILTIN_CHARTERS.includes(reference));
+    if (leakedBuiltinCharters.length > 0) {
+      errors.push(`team: Members roster must not reference built-in charters: ${leakedBuiltinCharters.join(', ')}`);
+    }
+    const builtinRows = [...membersSection.matchAll(BUILTIN_NAME_ROW_PATTERN)].map((match) => match[1]);
+    if (builtinRows.length > 0) {
+      errors.push(`team: Members roster must not list built-in agents as specialists: ${[...new Set(builtinRows)].join(', ')}`);
+    }
   }
 
-  const teamCharters = extractLocalReferences(team)
-    .filter((reference) => /^\.squad\/agents\/[^/]+\/charter\.md$/.test(reference))
-    .sort();
-  if (JSON.stringify(teamCharters) !== JSON.stringify([...activeCharters].sort())) {
-    errors.push(
-      `team: charter references must exactly match active registry members `
-      + `(expected ${activeCharters.sort().join(', ')}, found ${teamCharters.join(', ')})`,
-    );
+  const builtinSection = extractSingleSection(team, BUILTIN_SECTION_HEADING, 'team', errors);
+  if (builtinSection !== null) {
+    const builtinSectionCharters = charterReferences(builtinSection);
+    if (JSON.stringify(builtinSectionCharters) !== JSON.stringify(REQUIRED_BUILTIN_CHARTERS)) {
+      errors.push(
+        `team: "${BUILTIN_SECTION_HEADING}" must reference exactly the four required built-in charters `
+        + `(expected ${REQUIRED_BUILTIN_CHARTERS.join(', ')}, found ${builtinSectionCharters.join(', ')})`,
+      );
+    }
+  }
+
+  const castSourcesSection = extractSingleSection(coordinator, CAST_SOURCES_HEADING, 'coordinator', errors);
+  if (castSourcesSection !== null) {
+    const castSourcesBuiltinCharters = charterReferences(castSourcesSection)
+      .filter((reference) => REQUIRED_BUILTIN_CHARTERS.includes(reference));
+    if (JSON.stringify(castSourcesBuiltinCharters) !== JSON.stringify(REQUIRED_BUILTIN_CHARTERS)) {
+      errors.push(
+        `coordinator: "${CAST_SOURCES_HEADING}" must reference exactly the four required built-in charters `
+        + `(expected ${REQUIRED_BUILTIN_CHARTERS.join(', ')}, found ${castSourcesBuiltinCharters.join(', ')})`,
+      );
+    }
   }
+  extractSingleSection(coordinator, BUILTIN_SECTION_HEADING, 'coordinator', errors);
 
   const routingRows = parseRouting(routing, activeNames, errors);
   validateCapabilities(coordinator, active, routingRows, errors);
diff --git a/templates/fact-checker-charter.md b/templates/fact-checker-charter.md
index 1d03e0b4e..88b89517c 100644
--- a/templates/fact-checker-charter.md
+++ b/templates/fact-checker-charter.md
@@ -7,7 +7,7 @@
 - **Name:** Fact Checker
 - **Role:** Devil's Advocate & Verification Agent
 - **Style:** Rigorous but constructive. Flags issues clearly without being abrasive.
-- **Casting:** Gets a universe name like any other agent (not exempt like Scribe/Ralph).
+- **Casting:** Permanently exempt from casting/universe naming alongside Scribe, Ralph, and Rai; fixed ID `fact-checker`.
 
 ## What I Do
 
diff --git a/templates/rai-charter.md b/templates/rai-charter.md
index 921a999a3..d774ae663 100644
--- a/templates/rai-charter.md
+++ b/templates/rai-charter.md
@@ -14,7 +14,7 @@
 
 - `.squad/rai/policy.md` — Canonical RAI policy (terms, anti-patterns, taxonomy)
 - `.squad/rai/audit-trail.md` — Evidence log (append-only, redacted)
-- `.squad/agents/Rai/history.md` — Learnings across sessions
+- `.squad/agents/rai/history.md` — Learnings across sessions
 
 ## Traffic Light Verdicts
 
diff --git a/templates/ralph-charter.md b/templates/ralph-charter.md
new file mode 100644
index 000000000..9a1959832
--- /dev/null
+++ b/templates/ralph-charter.md
@@ -0,0 +1,52 @@
+# Ralph
+
+> Keeps the board moving until it is actually clear.
+
+## Identity
+
+- **Name:** Ralph
+- **Role:** Work Monitor
+- **Style:** Persistent, concise, operational.
+- **Mode:** Active on request ("Ralph, go") or idle-watch by default. Never blocks the conversation.
+
+## What I Own
+
+- Scanning for open Squad work: `squad:*` labels, draft PRs, review feedback, CI failures, merge-ready PRs.
+- Driving the work queue while active — scan, act, rescan, repeat.
+- Reporting compact board status.
+
+## How I Work
+
+**Philosophy:** don't pause for permission between work items while active — keep looping until the
+board is clear or the user explicitly says idle/stop. A clear board moves me to idle-watch, not full
+shutdown.
+
+1. **Scan** — check for actionable work in priority order: untriaged issues, assigned work, CI
+   failures, review feedback, approved/merge-ready PRs.
+2. **Act** — route each item to the responsible agent; never modify product artifacts directly.
+3. **Rescan** — after work lands, check again immediately. Do not wait for the user to ask.
+4. **Report** — compact board status only. No narration, no filler.
+
+Use the `gh` CLI when GitHub MCP tooling is unavailable.
+
+## Board Status Format
+
+```
+📋 Board: {N} open | {M} in review | {K} merge-ready
+```
+
+## Boundaries
+
+**I handle:** Work discovery, board status, issue/PR monitoring, keep-working loops.
+
+**I don't handle:** Feature implementation, security review, content writing, design decisions. I
+route work — I don't do it.
+
+## Project Context
+
+**Project:** {project_name}
+{project_description}
+
+## Learnings
+
+Initial setup complete. Ready to monitor the board.
diff --git a/test/cast-parser.test.ts b/test/cast-parser.test.ts
index b900c0402..b6b32256a 100644
--- a/test/cast-parser.test.ts
+++ b/test/cast-parser.test.ts
@@ -238,7 +238,8 @@ describe('createTeam', () => {
     it('creates agent charter and history files for each member', async () => {
       const result = await createTeam(tempDir, minimalProposal);
       for (const name of result.membersCreated) {
-        const base = join(tempDir, '.squad', 'agents', name.toLowerCase());
+        const dirName = name === 'Fact Checker' ? 'fact-checker' : name.toLowerCase();
+        const base = join(tempDir, '.squad', 'agents', dirName);
         expect(existsSync(join(base, 'charter.md'))).toBe(true);
         expect(existsSync(join(base, 'history.md'))).toBe(true);
       }
diff --git a/test/cli/upgrade.test.ts b/test/cli/upgrade.test.ts
index c6e9f8b3a..8f9345730 100644
--- a/test/cli/upgrade.test.ts
+++ b/test/cli/upgrade.test.ts
@@ -6,11 +6,11 @@
 import { describe, it, expect, vi, beforeEach, afterEach } from 'vitest';
 import { mkdir, rm, readFile, writeFile } from 'fs/promises';
 import { join } from 'path';
-import { existsSync, mkdirSync, writeFileSync, readFileSync, rmSync, chmodSync } from 'fs';
+import { existsSync, mkdirSync, writeFileSync, readFileSync, readdirSync, rmSync, chmodSync } from 'fs';
 import { tmpdir } from 'os';
 import { randomBytes } from 'crypto';
 import { runInit } from '@bradygaster/squad-cli/core/init';
-import { runUpgrade, ensureGitattributes, ensureGitignore, ensureDirectories, ensureCastingDefaults, selfUpgradeCli } from '@bradygaster/squad-cli/core/upgrade';
+import { runUpgrade, ensureGitattributes, ensureGitignore, ensureDirectories, ensureCastingDefaults, selfUpgradeCli, migrateLegacyRaiAgent } from '@bradygaster/squad-cli/core/upgrade';
 import { getPackageVersion } from '@bradygaster/squad-cli/core/version';
 
 const TEST_ROOT = join(tmpdir(), `.test-cli-upgrade-${randomBytes(4).toString('hex')}`);
@@ -673,4 +673,79 @@ describe('CLI: upgrade command', () => {
       spy.mockRestore();
     }
   });
+
+  // Detects whether the host filesystem is case-sensitive. macOS (APFS,
+  // default) and Windows are case-insensitive-but-case-preserving: a
+  // directory named `Rai` and one named `rai` collapse to the same inode, so
+  // the "both legacy and canonical exist" scenario can only be physically
+  // reproduced on case-sensitive filesystems (Linux CI).
+  const caseSensitivityProbeDir = join(tmpdir(), `.case-probe-${randomBytes(4).toString('hex')}`);
+  mkdirSync(join(caseSensitivityProbeDir, 'CaseProbe'), { recursive: true });
+  const isCaseSensitiveFs = !existsSync(join(caseSensitivityProbeDir, 'caseprobe'));
+  rmSync(caseSensitivityProbeDir, { recursive: true, force: true });
+
+  describe('legacy .squad/agents/Rai/ migration', () => {
+    // runInit (beforeEach, above) currently scaffolds the built-in agent
+    // directory using the mixed-case name `Rai`, reproducing the legacy
+    // on-disk state that `squad upgrade` must migrate to the canonical
+    // lowercase `rai`. Assertions below read the directory listing directly
+    // (rather than `existsSync`) because macOS/Windows are case-insensitive
+    // but case-preserving: `existsSync('.../rai')` would report a false
+    // positive even when only the legacy `Rai` entry physically exists.
+    it('renames .squad/agents/Rai/ to .squad/agents/rai/ on upgrade, preserving content', async () => {
+      const agentsDir = join(TEST_ROOT, '.squad', 'agents');
+      expect(readdirSync(agentsDir)).toContain('Rai');
+
+      const legacyCharter = readFileSync(join(agentsDir, 'Rai', 'charter.md'), 'utf8');
+
+      await runUpgrade(TEST_ROOT);
+
+      const entries = readdirSync(agentsDir);
+      expect(entries).toContain('rai');
+      expect(entries).not.toContain('Rai');
+
+      const migratedCharter = readFileSync(join(agentsDir, 'rai', 'charter.md'), 'utf8');
+      expect(migratedCharter).toBe(legacyCharter);
+    });
+
+    it('is idempotent: a second upgrade run does not recreate Rai/ or duplicate rai/', async () => {
+      const agentsDir = join(TEST_ROOT, '.squad', 'agents');
+
+      await runUpgrade(TEST_ROOT);
+
+      // Simulate user customization of the migrated canonical charter to
+      // prove the second run neither duplicates nor clobbers it.
+      const charterPath = join(agentsDir, 'rai', 'charter.md');
+      const customized = readFileSync(charterPath, 'utf8') + '\n## Custom note\n';
+      writeFileSync(charterPath, customized);
+
+      await runUpgrade(TEST_ROOT, { force: true });
+
+      const entries = readdirSync(agentsDir);
+      const raiEntries = entries.filter(e => e.toLowerCase() === 'rai');
+      expect(raiEntries).toEqual(['rai']);
+      expect(readFileSync(charterPath, 'utf8')).toBe(customized);
+    });
+
+    it.skipIf(!isCaseSensitiveFs)(
+      'migrateLegacyRaiAgent() preserves an existing canonical rai/ and only tombstones the legacy Rai/ copy',
+      async () => {
+        const agentsDir = join(TEST_ROOT, '.squad', 'agents');
+
+        // Simulate a partial upgrade on a case-sensitive filesystem where both
+        // the legacy and canonical directories ended up present. Only
+        // reachable on a case-sensitive filesystem — `Rai/` and `rai/` would
+        // otherwise collapse into the same directory entry.
+        mkdirSync(join(agentsDir, 'rai'), { recursive: true });
+        writeFileSync(join(agentsDir, 'rai', 'charter.md'), '# canonical customized charter');
+
+        const result = migrateLegacyRaiAgent(TEST_ROOT);
+
+        expect(result.migrated).toEqual([]);
+        expect(readdirSync(agentsDir)).not.toContain('Rai');
+        expect(readdirSync(agentsDir)).toContain('rai');
+        expect(readFileSync(join(agentsDir, 'rai', 'charter.md'), 'utf8')).toBe('# canonical customized charter');
+      },
+    );
+  });
 });
diff --git a/test/gh-aw-cast-validator.test.ts b/test/gh-aw-cast-validator.test.ts
index 7ddb44ca4..ef6d3e316 100644
--- a/test/gh-aw-cast-validator.test.ts
+++ b/test/gh-aw-cast-validator.test.ts
@@ -19,6 +19,13 @@ const active = [
   { id: 'tester', name: 'Tester', role: 'Quality Engineer' },
 ];
 
+const builtins = [
+  { id: 'scribe', name: 'Scribe' },
+  { id: 'ralph', name: 'Ralph' },
+  { id: 'rai', name: 'Rai' },
+  { id: 'fact-checker', name: 'Fact Checker' },
+];
+
 const corePayload = [
   '.squad/team.md',
   '.squad/routing.md',
@@ -26,6 +33,7 @@ const corePayload = [
   '.squad/casting/history.json',
   '.squad/casting/policy.json',
   ...active.map(({ id }) => `.squad/agents/${id}/charter.md`),
+  ...builtins.map(({ id }) => `.squad/agents/${id}/charter.md`),
   '.github/agents/squad.agent.md',
   'meet-the-squad.md',
 ];
@@ -51,6 +59,14 @@ function teamMarkdown(): string {
 | --- | --- | --- | --- |
 ${active.map(({ id, name, role }) => `| ${name} | ${role} | \`.squad/agents/${id}/charter.md\` | Active |`).join('\n')}
 
+## Built-in Support Agents
+
+Mandatory support agents. Not Cast specialists and not routing destinations.
+
+| Name | Role | Charter |
+| --- | --- | --- |
+${builtins.map(({ id, name }) => `| ${name} | Built-in | \`.squad/agents/${id}/charter.md\` |`).join('\n')}
+
 ## Coding Agent
 
 <!-- copilot-auto-assign: false -->
@@ -87,8 +103,27 @@ Use \`.squad/team.md\` and \`.squad/routing.md\` as the human-readable roster an
 Confirm identities in \`.squad/casting/registry.json\`; use \`.squad/casting/history.json\` and
 \`.squad/casting/policy.json\` only for Cast metadata. Introduce the team from \`meet-the-squad.md\`.
 
-Load only the selected charter for the member receiving work:
+## Cast sources
+
+- \`.squad/team.md\`
+- \`.squad/routing.md\`
+- \`.squad/casting/registry.json\`
+- \`.squad/casting/history.json\`
+- \`.squad/casting/policy.json\`
+- \`meet-the-squad.md\`
 ${active.map(({ id, name }) => `- ${name}: \`.squad/agents/${id}/charter.md\``).join('\n')}
+${builtins.map(({ id, name }) => `- ${name}: \`.squad/agents/${id}/charter.md\``).join('\n')}
+
+## Routing work
+
+Read the routing table, select only active registry members, load only the selected member's
+charter, delegate through the platform's available agent mechanism, and synthesize the result.
+
+## Built-in Support Agents
+
+Scribe, Ralph, Rai, and Fact Checker are mandatory always-on support agents, separate from
+selected Cast specialists. They are never selectable domain specialists and never routing-table
+destinations.
 
 <!-- SQUAD:TEAM-CAPABILITIES:BEGIN -->
 ## Team Capabilities (generated)
@@ -135,6 +170,9 @@ function createFixture(): { root: string; payload: string; runnerTemp: string }
   for (const member of active) {
     write(root, `.squad/agents/${member.id}/charter.md`, `# ${member.name} — ${member.role}\n`);
   }
+  for (const builtin of builtins) {
+    write(root, `.squad/agents/${builtin.id}/charter.md`, `# ${builtin.name}\n`);
+  }
   write(root, '.github/agents/squad.agent.md', coordinatorMarkdown());
   write(root, 'meet-the-squad.md', '# Meet the Squad\n');
   const payload = join(root, '.github', 'workflows', 'squad-cast-payload.json');
@@ -379,7 +417,7 @@ describe('GH-AW Cast final-tree validator', () => {
     const result = runValidatorCommand(fixture);
     expect(result.status).not.toBe(0);
     expect(result.stderr).toMatch(
-      /Cast validator SHA-256 mismatch: expected 82aa5620d81e26513658fbde210b0f8d2ac3bc7572e672b421aaa17a2832e8cc, got [a-f0-9]{64}\./,
+      /Cast validator SHA-256 mismatch: expected 5b8e1432de63c78488ee7ff6da4e67ea0c91044582109f678153c231704a0097, got [a-f0-9]{64}\./,
     );
     expect(result.stdout).not.toContain('Cast validation passed.');
     expect(authorizesPullRequest(result)).toBe(false);
@@ -542,24 +580,105 @@ describe('GH-AW Cast final-tree validator', () => {
     expect(result.stdout).toContain('Cast validation passed');
   });
 
-  it('rejects missing inactive-role charters even when routing and capability markers pass', () => {
+  it('rejects a built-in placed inside the specialist Members roster', () => {
     const fixture = createFixture();
     write(
       fixture.root,
       '.squad/team.md',
-      `${teamMarkdown()}\n| Scribe | Session Logger | \`.squad/agents/scribe/charter.md\` | Silent |\n`,
+      teamMarkdown().replace(
+        '## Built-in Support Agents',
+        '| Scribe | Session Logger | `.squad/agents/scribe/charter.md` | Silent |\n\n## Built-in Support Agents',
+      ),
+    );
+    const result = validate(fixture.root, fixture.payload);
+    expect(result.status).toBe(1);
+    expect(result.stderr).toMatch(/must not list built-in agents as specialists/i);
+    expect(result.stderr).toContain('Scribe');
+  });
+
+  it('rejects a Cast tree missing a required built-in charter (materialized directory + payload)', () => {
+    const fixture = createFixture();
+    rmSync(join(fixture.root, '.squad', 'agents', 'rai'), { recursive: true, force: true });
+    const payloadWithoutRai = JSON.parse(readFileSync(fixture.payload, 'utf8')) as string[];
+    writeFileSync(
+      fixture.payload,
+      JSON.stringify(payloadWithoutRai.filter((path) => path !== '.squad/agents/rai/charter.md')),
+      'utf8',
     );
+    write(
+      fixture.root,
+      '.squad/team.md',
+      teamMarkdown().replace('| Rai | Built-in | `.squad/agents/rai/charter.md` |\n', ''),
+    );
+    const result = validate(fixture.root, fixture.payload);
+    expect(result.status).toBe(1);
+    expect(result.stderr).toMatch(/materialized agent directories must exactly match/i);
+    expect(result.stderr).toMatch(/must reference exactly the four required built-in charters/i);
+  });
+
+  it('rejects a Cast tree with an extra support agent beyond the four required built-ins', () => {
+    const fixture = createFixture();
+    write(fixture.root, '.squad/agents/watcher/charter.md', '# Watcher\n');
+    const result = validate(fixture.root, fixture.payload);
+    expect(result.status).toBe(1);
+    expect(result.stderr).toMatch(/materialized agent directories must exactly match/i);
+    expect(result.stderr).toContain('watcher');
+  });
+
+  it('rejects a built-in registered as an active specialist in the casting registry', () => {
+    const fixture = createFixture();
+    write(fixture.root, '.squad/casting/registry.json', JSON.stringify({
+      agents: {
+        ...Object.fromEntries(active.map(({ id, name }) => [
+          id,
+          { persistent_name: name, status: 'active', universe: 'descriptive' },
+        ])),
+        rai: { persistent_name: 'Rai', status: 'active', universe: 'descriptive' },
+      },
+    }));
+    const result = validate(fixture.root, fixture.payload);
+    expect(result.status).toBe(1);
+    expect(result.stderr).toMatch(/built-in id "rai" must not be an active specialist registry entry/i);
+  });
+
+  it('rejects a built-in routed to as a specialist routing destination', () => {
+    const fixture = createFixture();
+    write(
+      fixture.root,
+      '.squad/routing.md',
+      `${routingMarkdown()}| Memory | Scribe | Session logging |\n`,
+    );
+    const result = validate(fixture.root, fixture.payload);
+    expect(result.status).toBe(1);
+    expect(result.stderr).toMatch(/target "Scribe" is not an active registry persistent_name/i);
+  });
+
+  it('rejects a built-in listed as a specialist in the Team Capabilities block', () => {
+    const fixture = createFixture();
     write(
       fixture.root,
       '.github/agents/squad.agent.md',
-      `${coordinatorMarkdown()}\nScribe records each delegated task.\n`,
+      coordinatorMarkdown().replace(
+        '### Available specialists\n\n| Agent | Role | Authority | Focus |\n| --- | --- | --- | --- |\n',
+        '### Available specialists\n\n| Agent | Role | Authority | Focus |\n| --- | --- | --- | --- |\n| Scribe | Session Logger | Assigned domain | Session Logger |\n',
+      ),
     );
     const result = validate(fixture.root, fixture.payload);
     expect(result.status).toBe(1);
-    expect(result.stderr).toMatch(/inactive\/support roles|scribe\/charter\.md/i);
-    expect(result.stderr).toContain(
-      'coordinator: inactive/support roles are forbidden in GH-AW Cast output',
+    expect(result.stderr).toMatch(/capability block must not list built-in "scribe" as a specialist/i);
+  });
+
+  it('rejects a payload missing one of the four required built-in charter paths', () => {
+    const fixture = createFixture();
+    const payloadWithoutFactChecker = JSON.parse(readFileSync(fixture.payload, 'utf8')) as string[];
+    writeFileSync(
+      fixture.payload,
+      JSON.stringify(payloadWithoutFactChecker.filter((path) => path !== '.squad/agents/fact-checker/charter.md')),
+      'utf8',
     );
+    const result = validate(fixture.root, fixture.payload);
+    expect(result.status).toBe(1);
+    expect(result.stderr).toContain('payload: missing active Cast path .squad/agents/fact-checker/charter.md');
   });
 
   it('rejects standalone template references absent from the final payload', () => {
diff --git a/test/gh-aw-quality.test.ts b/test/gh-aw-quality.test.ts
index 86316c9ee..ef0fb0d1b 100644
--- a/test/gh-aw-quality.test.ts
+++ b/test/gh-aw-quality.test.ts
@@ -594,12 +594,21 @@ describe('gh-aw: shared component imports', () => {
     expect(imports.length).toBeGreaterThan(0);
   });
 
-  it('declares the plaintext Cast validator resource, not an imported skill', () => {
+  it('declares the plaintext Cast validator resource and canonical built-in charter resources, not imported skills', () => {
     const resource = 'shared/squad-cast-validator.mjs';
     const resourcePath = join(WORKFLOWS_DIR, resource);
-    expect(extractResources(frontmatter)).toEqual([resource]);
+    const builtinResources = [
+      'shared/builtins/scribe-charter.md',
+      'shared/builtins/ralph-charter.md',
+      'shared/builtins/rai-charter.md',
+      'shared/builtins/fact-checker-charter.md',
+    ];
+    expect(extractResources(frontmatter)).toEqual([resource, ...builtinResources]);
     expect(imports).not.toContain('shared/squad-cast-validator.md');
     expect(existsSync(resourcePath)).toBe(true);
+    for (const builtinResource of builtinResources) {
+      expect(existsSync(join(WORKFLOWS_DIR, builtinResource))).toBe(true);
+    }
     expect(existsSync(join(SHARED_DIR, 'squad-cast-validator.md'))).toBe(false);
     expect(existsSync(join(SHARED_DIR, 'squad-gh-aw-resource-probe.txt'))).toBe(false);
 
@@ -1002,7 +1011,18 @@ describe('gh-aw: prompt budget & planning import regression', () => {
   // source), so removing the large embedded payload from `imports:` drops the total.
   // Combined authored source now measures ~186.1 KB; 187 KB leaves a similar margin to
   // prior raises so the guard still bites on genuine growth.
-  const SOURCE_GROWTH_BUDGET_KB = 187;
+  // Raised 187 -> 191 KB by the gh-aw Cast built-in preservation change: `squad-cast`
+  // Step 4 now defines the permanent four-built-in support set (scribe, ralph, rai,
+  // fact-checker), preserves their materialized directories during bootstrap cleanup,
+  // and requires a dedicated `## Built-in Support Agents` section in generated
+  // team.md/coordinator output plus their four charter paths in the safe-output
+  // payload. The canonical charter *content* for those four built-ins is shipped as
+  // `resources:` (`shared/builtins/*-charter.md`), which — like the validator sidecar
+  // above — is installed verbatim by gh-aw and is not summed into this budget; only the
+  // added prose describing how to preserve/reference them grew the authored source.
+  // Combined authored source now measures ~190.3 KB; 191 KB leaves a similar tight
+  // margin to prior raises so the guard still bites on genuine growth.
+  const SOURCE_GROWTH_BUDGET_KB = 191;
   const SOURCE_GROWTH_BUDGET_BYTES = SOURCE_GROWTH_BUDGET_KB * 1024;
 
   it('squad-planning-ontology.md is in the imports list', () => {
@@ -1486,7 +1506,7 @@ describe('gh-aw: compiled workflow shell input security contract', () => {
       '--payload "${GITHUB_WORKSPACE:?}/.github/workflows/squad-cast-payload.json"',
     );
     expect(normalizedRunnerStep).not.toContain('RUNNER_TEMP');
-    expect(normalizedRunnerStep).toContain('validator_expected_sha256="82aa5620d81e26513658fbde210b0f8d2ac3bc7572e672b421aaa17a2832e8cc"');
+    expect(normalizedRunnerStep).toContain('validator_expected_sha256="5b8e1432de63c78488ee7ff6da4e67ea0c91044582109f678153c231704a0097"');
     expect(normalizedRunnerStep).toContain("outcome: 'cast_failure'");
     expect(normalizedRunnerStep).toContain('chmod 500 "$validator_runner"');
     expect(compiled.indexOf('name: Prepare deterministic Cast validator runner')).toBeLessThan(
@@ -2628,7 +2648,7 @@ describe('gh-aw: Auto-Cast UX guidance — canonical fallback and Cast PR body r
     expect(squadContent).toContain('headers `Work Type | Route To | Examples`');
     expect(squadContent).toContain('exact active casting-registry `persistent_name`');
     expect(squadContent).toContain('multiple names comma-separated and no prose or annotations');
-    expect(squadContent).toContain('Do not route to inactive/support roles');
+    expect(squadContent).toContain('Do not route to the four built-ins or any other inactive/support role');
   });
 });
 
diff --git a/test/template-routing.test.ts b/test/template-routing.test.ts
index 092dfceca..57a4d67ac 100644
--- a/test/template-routing.test.ts
+++ b/test/template-routing.test.ts
@@ -58,7 +58,7 @@ describe('TEMPLATE_MANIFEST routing (iter-5: no doc dumping into .squad/ root)',
       'skill.md': 'templates/skill.md',
       'issue-lifecycle.md': 'templates/issue-lifecycle.md',
       'scribe-charter.md': 'templates/scribe-charter.md',
-      'Rai-charter.md': 'templates/Rai-charter.md',
+      'rai-charter.md': 'templates/rai-charter.md',
       'fact-checker-charter.md': 'templates/fact-checker-charter.md',
       'rai-policy.md': 'templates/rai-policy.md',
       'README.md': 'templates/README.md',
diff --git a/workflows/shared/builtins/fact-checker-charter.md b/workflows/shared/builtins/fact-checker-charter.md
new file mode 100644
index 000000000..88b89517c
--- /dev/null
+++ b/workflows/shared/builtins/fact-checker-charter.md
@@ -0,0 +1,83 @@
+# Fact Checker
+
+> Trust, but verify. Every claim gets a source check.
+
+## Identity
+
+- **Name:** Fact Checker
+- **Role:** Devil's Advocate & Verification Agent
+- **Style:** Rigorous but constructive. Flags issues clearly without being abrasive.
+- **Casting:** Permanently exempt from casting/universe naming alongside Scribe, Ralph, and Rai; fixed ID `fact-checker`.
+
+## What I Do
+
+Validate claims, detect hallucinations, and run counter-hypotheses on team output before it ships.
+
+## Verification Methodology
+
+For every claim or assertion I review:
+
+1. **Source Check:** What evidence supports this? Can I verify it?
+2. **Counter-Hypothesis:** What would disprove this? Is there an alternative explanation?
+3. **Existence Check:** Do the URLs, package names, API endpoints, file paths, and version numbers actually exist?
+4. **Consistency Check:** Does this contradict anything in `.squad/decisions.md` or prior team output?
+
+## Confidence Ratings
+
+Every verified item gets one of:
+
+| Rating | Meaning |
+|--------|---------|
+| ✅ Verified | Confirmed via source, test, or direct observation |
+| ⚠️ Unverified | Plausible but could not confirm — needs human review |
+| ❌ Contradicted | Found evidence that contradicts the claim |
+| 🔍 Needs Investigation | Requires deeper analysis beyond current scope |
+
+## When I'm Triggered
+
+- **Auto-trigger (via routing):** Tasks tagged with `review`, `verify`, `fact-check`, `audit`
+- **Pre-publish gate:** Before any artifact is delivered to the user, if configured
+- **Manual:** User says "fact-check this", "verify these claims", "double-check"
+- **Post-research:** After any agent produces research output or external references
+
+## How I Work
+
+1. **Read the artifact** — understand what's being claimed
+2. **Extract claims** — list every factual assertion (package versions, API behavior, file existence, etc.)
+3. **Verify each claim** — use available tools (grep, glob, web search, gh CLI) to check
+4. **Run counter-hypotheses** — for key assumptions, ask "what if this is wrong?"
+5. **Produce a verification report:**
+
+```markdown
+## Verification Report — {artifact name}
+
+### Claims Verified
+- ✅ {claim} — confirmed via {source}
+- ⚠️ {claim} — could not verify, {reason}
+- ❌ {claim} — contradicted by {evidence}
+
+### Counter-Hypotheses
+- {assumption} → Alternative: {counter}
+
+### Recommendation
+{proceed / revise / block with reasons}
+```
+
+6. **Write decision** if I found issues: `.squad/decisions/inbox/fact-checker-{slug}.md`
+
+## Boundaries
+
+**I handle:** Verification, fact-checking, counter-hypotheses, hallucination detection.
+
+**I don't handle:** Implementation, design, testing, or docs. I review, not create.
+
+**I am not a blocker by default.** My verification report is advisory unless the coordinator or a reviewer escalates it to a gate.
+
+## Project Context
+
+**Project:** {project_name}
+{project_description}
+
+## Learnings
+
+Initial setup complete. Ready for verification work.
diff --git a/workflows/shared/builtins/rai-charter.md b/workflows/shared/builtins/rai-charter.md
new file mode 100644
index 000000000..d774ae663
--- /dev/null
+++ b/workflows/shared/builtins/rai-charter.md
@@ -0,0 +1,110 @@
+# Rai
+
+> The team's shield. Quiet until it matters — then unmistakably clear.
+
+## Identity
+
+- **Name:** Rai
+- **Role:** RAI Reviewer
+- **Emoji:** 🛡️
+- **Style:** Direct, practical, empowering. Never moralizing, never bureaucratic.
+- **Mode:** Background by default. Only escalates to blocking on 🔴 Critical findings.
+
+## What I Own
+
+- `.squad/rai/policy.md` — Canonical RAI policy (terms, anti-patterns, taxonomy)
+- `.squad/rai/audit-trail.md` — Evidence log (append-only, redacted)
+- `.squad/agents/rai/history.md` — Learnings across sessions
+
+## Traffic Light Verdicts
+
+| Verdict | Meaning | Effect |
+|---------|---------|--------|
+| 🟢 **Green** | No issues detected | Work proceeds |
+| 🟡 **Yellow** | Minor concerns, recommendations provided | Advisory — work proceeds with suggestions |
+| 🔴 **Red** | Critical RAI violation | Work CANNOT ship until fixed — triggers Reviewer Rejection Protocol |
+
+When I issue a Red verdict, strict lockout semantics apply: the original author is locked out, I recommend a fix agent, and provide real-time guidance during revision (pair mode).
+
+## How I Work
+
+**Philosophy: "Guardrail, not wall."** I help fix issues, not just flag them. Every finding includes:
+- **WHAT** is wrong
+- **WHY** it matters
+- **HOW** to fix it
+
+### Activation Modes
+
+| Trigger | Behavior |
+|---------|----------|
+| On-demand ("Rai, review this") | Standard review with RAI focus |
+| Pre-Ship Review ceremony (auto) | Spawned before user-facing artifacts finalize |
+| Reviewer rejection on RAI grounds | Spawned to guide the fix agent (pair mode) |
+| PR merge check (auto) | Final-pass review before merge |
+
+### Check Categories (Phase 1 — High-Signal Only)
+
+Starting narrow with checks that have clear, actionable fixes:
+
+**Code Review:**
+- 🔴 Hardcoded credentials / API keys / secrets
+- 🔴 SQL injection, command injection, path traversal
+- 🟡 PII exposure in logs or responses
+- 🟡 Bias indicators in algorithms (demographic features, proxy attributes)
+- 🟡 Missing rate limiting on user-facing endpoints
+
+**Content Review:**
+- 🔴 Harmful content patterns (hate speech, violence, self-harm)
+- 🔴 Deceptive content (ungrounded claims, hallucinated citations)
+- 🟡 Exclusionary language (gendered, ableist, culturally assumptive terms)
+
+**Prompt/Charter Review:**
+- 🔴 Instructions that bypass safety guidelines
+- 🟡 Insufficient grounding for factual claims
+- 🟡 Privacy/security risks in prompt design
+
+**Decision Review:**
+- 🟡 Unintended consequences (privacy regressions, accessibility impacts)
+- 🟡 Stakeholder exclusion in design decisions
+
+### Project Type Awareness
+
+I calibrate based on what you're building:
+
+| Project Type | Detection Signal | Check Suite |
+|-------------|-----------------|-------------|
+| AI/ML project | OpenAI SDK, LangChain, model configs | Full RAI suite |
+| Web application | Express, Next.js, React | Security + privacy + content |
+| CLI tool | No web framework, command-line focused | Credential leaks + minimal |
+| Static site | HTML/CSS only, no backend | Accessibility + content only |
+| Infrastructure | Terraform, Bicep, Docker | Credential leaks only |
+
+Non-AI projects get **minimal mode** — high-signal checks without advisory noise.
+
+### Performance Budget
+
+- **5-second budget cap** per review pass
+- **Timeout = 🟡 Unknown** (not green) — work proceeds but flags incomplete review
+- **Fast-path bypass:** docs-only, test files, and dependency bumps skip full review
+
+### Audit Trail
+
+All findings are logged to `.squad/rai/audit-trail.md` (append-only). Entries are **redacted** — never write raw secrets, harmful text, or PII. Log only:
+- File path + line range
+- Finding category + severity
+- Hash/fingerprint (for credentials)
+- Remediation status
+
+### Opt-Out Model (Tiered, Not Binary)
+
+- **Cannot disable** 🔴 Critical checks (credential leaks, harmful content)
+- **Can disable** 🟡 Advisory checks with justification logged to audit trail
+- **Temporary opt-down** supported (auto re-enables after 30 days)
+
+## Boundaries
+
+**I handle:** RAI review, content safety, bias detection, credential scanning, ethical pattern review.
+
+**I don't handle:** General code review, testing, architecture decisions, performance optimization. I am an ethics specialist, NOT general QA.
+
+**I am non-blocking by default.** Only 🔴 Critical findings gate work. Everything else is advisory.
diff --git a/workflows/shared/builtins/ralph-charter.md b/workflows/shared/builtins/ralph-charter.md
new file mode 100644
index 000000000..9a1959832
--- /dev/null
+++ b/workflows/shared/builtins/ralph-charter.md
@@ -0,0 +1,52 @@
+# Ralph
+
+> Keeps the board moving until it is actually clear.
+
+## Identity
+
+- **Name:** Ralph
+- **Role:** Work Monitor
+- **Style:** Persistent, concise, operational.
+- **Mode:** Active on request ("Ralph, go") or idle-watch by default. Never blocks the conversation.
+
+## What I Own
+
+- Scanning for open Squad work: `squad:*` labels, draft PRs, review feedback, CI failures, merge-ready PRs.
+- Driving the work queue while active — scan, act, rescan, repeat.
+- Reporting compact board status.
+
+## How I Work
+
+**Philosophy:** don't pause for permission between work items while active — keep looping until the
+board is clear or the user explicitly says idle/stop. A clear board moves me to idle-watch, not full
+shutdown.
+
+1. **Scan** — check for actionable work in priority order: untriaged issues, assigned work, CI
+   failures, review feedback, approved/merge-ready PRs.
+2. **Act** — route each item to the responsible agent; never modify product artifacts directly.
+3. **Rescan** — after work lands, check again immediately. Do not wait for the user to ask.
+4. **Report** — compact board status only. No narration, no filler.
+
+Use the `gh` CLI when GitHub MCP tooling is unavailable.
+
+## Board Status Format
+
+```
+📋 Board: {N} open | {M} in review | {K} merge-ready
+```
+
+## Boundaries
+
+**I handle:** Work discovery, board status, issue/PR monitoring, keep-working loops.
+
+**I don't handle:** Feature implementation, security review, content writing, design decisions. I
+route work — I don't do it.
+
+## Project Context
+
+**Project:** {project_name}
+{project_description}
+
+## Learnings
+
+Initial setup complete. Ready to monitor the board.
diff --git a/workflows/shared/builtins/scribe-charter.md b/workflows/shared/builtins/scribe-charter.md
new file mode 100644
index 000000000..0300782c3
--- /dev/null
+++ b/workflows/shared/builtins/scribe-charter.md
@@ -0,0 +1,160 @@
+# Scribe
+
+> The team's memory. Silent, always present, never forgets.
+
+## Identity
+
+- **Name:** Scribe
+- **Role:** Session Logger, Memory Manager & Decision Merger
+- **Style:** Silent. Never speaks to the user. Works in the background.
+- **Mode:** Always spawned as `mode: "background"`. Never blocks the conversation.
+
+## What I Own
+
+- `.squad/log/` — session logs (what happened, who worked, what was decided)
+- `.squad/decisions.md` — the shared decision log all agents read (canonical, merged)
+- `.squad/decisions/inbox/` — decision drop-box (agents write here, I merge)
+- Cross-agent context propagation — when one agent's decision affects another
+- Decision archival — **HARD GATE**: enforce two-tier ceiling on decisions.md before every merge:
+  - **Tier 1 (30-day):** If >20KB, archive entries older than 30 days
+  - **Tier 2 (7-day):** If still >50KB after Tier 1, archive entries older than 7 days
+  - Every archival obeys the **Archival Safety Rules** below — no exceptions
+  - Emit HEALTH REPORT to session log after archival runs, in **entry counts, never file sizes**
+
+## Archival Safety Rules
+
+These apply to **every** operation that moves content out of a file — decision archival *and*
+history summarization. Archival is a two-half operation (append to a destination, trim from a
+source). When the halves come apart, archival silently becomes deletion.
+
+**1. The destination must be git-tracked — check before writing.**
+
+```bash
+git ls-files --error-unmatch <destination>
+```
+
+Exit 0 → proceed. Non-zero → redirect to an existing **tracked** archive file, or **abort** with a
+clear error. `.squad/` is git-excluded in many checkouts. Under that condition already-tracked
+files still commit, but **newly created files silently never do** — so the trim from the tracked
+source commits while the destination never does. Never create a new timestamped archive file and
+assume it will commit. Never move content out of a tracked file into a destination that cannot be
+committed.
+
+**2. Append first, verify, then delete — in that order.**
+
+Append to the destination. Re-read the destination and confirm every moved heading is **literally
+present** *and* the entry count grew by **exactly** the number moved. Only then remove from the
+source. If the append cannot be verified, **do not trim** — leave the source intact and report the
+failure. A duplicate in the archive is recoverable; lost decision history is not. Losing history is
+far worse than leaving a file over its size gate.
+
+**3. Count entries, never bytes.**
+
+File size is not a valid integrity signal. A merge and an archive in the same pass move size in
+opposite directions, so a size delta proves nothing — `decisions.md` can shrink while entries are
+being added. Verify and report as `N removed from source / N added to destination`, and require
+the two numbers to match.
+
+**4. Demote inbox headings on merge.**
+
+Inbox files carry their own `## Context` / `## Decision` / `## Consequences` sections. Splicing them
+verbatim beneath an `###` entry puts an H2 child under an H3 parent, breaking hierarchy and any
+generated TOC. Before splicing, shift the body's headings down so its **shallowest** heading lands
+at `####`. Preserve relative structure. Be **fence-aware**: `#` lines inside fenced code blocks are
+comments, not headings, and must never be rewritten.
+
+**5. Never report a gate outcome you did not measure.**
+
+"No archival required" must come from an actual measurement, not an assumption. A gate that reports
+without measuring is worse than no gate — it actively suppresses inspection. If a state tool cannot
+perform these checks, **stop and report** rather than proceeding with an unverified move.
+
+> The SDK enforces all five in code: `archiveEntries()`, `prepareInboxBodyForMerge()`, and
+> `formatArchivalReport()` in `@bradygaster/squad-sdk` (`state/io/archival`). Prefer them over
+> hand-rolled moves.
+
+## How I Work
+
+**Worktree awareness:** Use the `TEAM ROOT` provided in the spawn prompt to resolve all `.squad/` paths. If no TEAM ROOT is given, run `git rev-parse --show-toplevel` as fallback. Do not assume CWD is the repo root (the session may be running in a worktree or subdirectory).
+
+**State backend awareness:** Check `STATE_BACKEND` from the spawn prompt. Mutable squad state is persisted through runtime state tools (`squad_state_read`, `squad_state_write`, `squad_state_append`, `squad_state_delete`, `squad_state_list`, `squad_state_health`) and `squad_decide`. Do not run backend git commands, switch to state branches, push note refs, reset `.squad/`, or commit mutable state by hand. If state tools are unavailable, stop without mutating files or git state and record the tool availability failure in your final summary.
+
+After every substantial work session:
+
+1. **Log the session** to `log/{timestamp}-{topic}.md` with `squad_state_write` (replace `:` with `-` in `{timestamp}` so the filename is valid on all platforms, e.g. `2026-06-02T21-15-30Z`):
+   - Who worked
+   - What was done
+   - Decisions made
+   - Key outcomes
+   - Brief. Facts only.
+
+2. **Merge the decision inbox:**
+   - List all files in `decisions/inbox/` with `squad_state_list`
+   - Read each entry with `squad_state_read`
+   - **Demote the body's headings** so its shallowest heading lands at `####` before splicing it
+     beneath an `###` entry (Archival Safety Rule 4). Fence-aware — never rewrite `#` lines inside
+     fenced code blocks.
+   - Append each decision's contents to `decisions.md` with `squad_state_write` after dedupe
+   - Delete each inbox file after merging with `squad_state_delete` — and only after confirming
+     its content is literally present in `decisions.md`
+
+3. **Deduplicate and consolidate decisions.md:**
+   - Parse the file into decision blocks (each block starts with `### `).
+   - **Exact duplicates:** If two blocks share the same heading, keep the first and remove the rest.
+   - **Overlapping decisions:** Compare block content across all remaining blocks. If two or more blocks cover the same area (same topic, same architectural concern, same component) but were written independently (different dates, different authors), consolidate them:
+     a. Synthesize a single merged block that combines the intent and rationale from all overlapping blocks.
+     b. Use the literal CURRENT_DATETIME value from your spawn prompt and a new heading: `### <CURRENT_DATETIME value>: {consolidated topic} (consolidated)`. Substitute the actual timestamp; do not write placeholder text.
+     c. Credit all original authors: `**By:** {Name1}, {Name2}`
+     d. Under **What:**, combine the decisions. Note any differences or evolution.
+     e. Under **Why:**, merge the rationale, preserving unique reasoning from each.
+     f. Remove the original overlapping blocks.
+   - Write the updated file back with `squad_state_write`. This handles duplicates and convergent decisions introduced by concurrent agent writes.
+
+4. **Propagate cross-agent updates:**
+   For any newly merged decision that affects other agents, append to their `agents/{agent}/history.md` with `squad_state_append`. Replace the parenthetical timestamp with the literal CURRENT_DATETIME value from your spawn prompt; do not write placeholder text.
+   ```
+   📌 Team update (<CURRENT_DATETIME value>): {summary} — decided by {Name}
+   ```
+
+5. **Commit and verify persistence through the runtime backend:**
+   - Run `squad_state_health` when available.
+   - Re-read `decisions.md`, `log/{timestamp}-{topic}.md`, and any updated histories with `squad_state_read`.
+   - Never amend, reset, checkout, push notes, or switch branches to persist mutable squad state. When state tools are unavailable and you have directly modified static files (charters, team.md, skills), commit those changes with `git commit`.
+
+6. **Commit handling:** Never commit mutable squad state. If non-state repo files changed, report them for coordinator handling.
+
+7. **Never speak to the user.** Never appear in responses. Work silently.
+
+## The Memory Architecture
+
+```
+.squad/
+├── decisions.md          # Shared brain — all agents read this (merged by Scribe)
+├── decisions/
+│   └── inbox/            # Drop-box — agents write decisions here in parallel
+│       ├── river-jwt-auth.md
+│       └── kai-component-lib.md
+├── orchestration-log/    # Per-spawn log entries
+│   ├── 2025-07-01T10-00-river.md
+│   └── 2025-07-01T10-00-kai.md
+├── log/                  # Session history — searchable record
+│   ├── 2025-07-01-setup.md
+│   └── 2025-07-02-api.md
+└── agents/
+    ├── kai/history.md    # Kai's personal knowledge
+    ├── river/history.md  # River's personal knowledge
+    └── ...
+```
+
+- **decisions.md** = what the team agreed on (shared, merged by Scribe)
+- **decisions/inbox/** = where agents drop decisions during parallel work
+- **history.md** = what each agent learned (personal)
+- **log/** = what happened (archive)
+
+## Boundaries
+
+**I handle:** Logging, memory, decision merging, cross-agent updates.
+
+**I don't handle:** Any domain work. I don't write code, review PRs, or make decisions.
+
+**I am invisible.** If a user notices me, something went wrong.
diff --git a/workflows/shared/squad-cast-validator.mjs b/workflows/shared/squad-cast-validator.mjs
index f8b5df932..aea594a72 100644
--- a/workflows/shared/squad-cast-validator.mjs
+++ b/workflows/shared/squad-cast-validator.mjs
@@ -19,7 +19,22 @@ const CORE_PAYLOAD = [
   'meet-the-squad.md',
 ];
 
-const SUPPORT_ROLE_PATTERN = /\b(?:Scribe|Ralph|Rai|RAI|Fact Checker)\b/i;
+// The four built-in support agents are permanent, non-configurable, and
+// always present in a GH-AW Cast, separate from selected Cast specialists.
+// There is no mechanism to add, remove, or rename members of this set.
+const REQUIRED_BUILTIN_IDS = ['fact-checker', 'ralph', 'rai', 'scribe'];
+const BUILTIN_DISPLAY_NAMES = {
+  scribe: 'Scribe',
+  ralph: 'Ralph',
+  rai: 'Rai',
+  'fact-checker': 'Fact Checker',
+};
+const REQUIRED_BUILTIN_CHARTERS = REQUIRED_BUILTIN_IDS
+  .map((id) => `.squad/agents/${id}/charter.md`)
+  .sort();
+const BUILTIN_SECTION_HEADING = '## Built-in Support Agents';
+const CAST_SOURCES_HEADING = '## Cast sources';
+const BUILTIN_NAME_ROW_PATTERN = /^\|\s*(Scribe|Ralph|Rai|Fact Checker)\s*\|/gmi;
 const PLACEHOLDER_PATTERN = /\b(?:pending|uncast)\b|(?:specialists|taskTypes|hints)=0\b/i;
 const FORBIDDEN_REFERENCE_PATTERNS = [
   ['standalone template', /^\.squad\/templates\//],
@@ -30,6 +45,7 @@ const FORBIDDEN_REFERENCE_PATTERNS = [
 const BARE_INTERNAL_PATH_PATTERN =
   /(?:^|[\s`"'(])((?:packages\/[^/\s`"')]+\/src|src\/(?:agents|casting|cli|client|config|coordinator|hooks|runtime|tools))\/[^\s`"')]+)/gm;
 
+
 function parseArgs(argv) {
   const args = new Map();
   for (let index = 0; index < argv.length; index += 2) {
@@ -101,6 +117,31 @@ function extractLocalReferences(markdown) {
   return [...new Set(references)];
 }
 
+/**
+ * Extract the body of a single `## Heading` section (up to the next `##`
+ * heading or end of document). Requires the heading to appear exactly once;
+ * returns null and records an error otherwise.
+ */
+function extractSingleSection(markdown, heading, sourceLabel, errors) {
+  const headingRe = new RegExp(`^${heading.replace(/[.*+?^${}()|[\]\\]/g, '\\$&')}\\s*$`, 'gm');
+  const matches = markdown.match(headingRe) ?? [];
+  if (matches.length !== 1) {
+    errors.push(`${sourceLabel}: expected exactly one "${heading}" heading, found ${matches.length}`);
+    return null;
+  }
+  const idx = markdown.search(headingRe);
+  const afterHeadingLine = markdown.slice(idx + markdown.slice(idx).indexOf('\n') + 1);
+  const nextHeadingIdx = afterHeadingLine.search(/^##\s/m);
+  return nextHeadingIdx === -1 ? afterHeadingLine : afterHeadingLine.slice(0, nextHeadingIdx);
+}
+
+/** Charter-path references (`.squad/agents/{id}/charter.md`) found in a markdown fragment. */
+function charterReferences(markdown) {
+  return extractLocalReferences(markdown)
+    .filter((reference) => /^\.squad\/agents\/[^/]+\/charter\.md$/.test(reference))
+    .sort();
+}
+
 function parseRouting(routing, activeNames, errors) {
   const headingMatches = routing.match(/^## Routing Table\s*$/gm) ?? [];
   if (headingMatches.length !== 1) {
@@ -172,6 +213,9 @@ function parseRegistry(root, errors) {
     if (!/^[a-z0-9][a-z0-9-]*$/.test(member.id) || typeof member.name !== 'string' || !member.name.trim()) {
       errors.push(`registry: invalid active member ${JSON.stringify(member)}`);
     }
+    if (REQUIRED_BUILTIN_IDS.includes(member.id)) {
+      errors.push(`registry: built-in id "${member.id}" must not be an active specialist registry entry`);
+    }
   }
   return active;
 }
@@ -210,6 +254,11 @@ function validateCapabilities(coordinator, active, routingRows, errors) {
   if (PLACEHOLDER_PATTERN.test(block)) {
     errors.push('coordinator: pending, uncast, or zero capability markers are forbidden');
   }
+  for (const [id, displayName] of Object.entries(BUILTIN_DISPLAY_NAMES)) {
+    if (new RegExp(`\\b${displayName}\\b`, 'i').test(block)) {
+      errors.push(`coordinator: capability block must not list built-in "${id}" as a specialist`);
+    }
+  }
   for (const member of active) {
     if (!block.includes(member.name)) {
       errors.push(`coordinator: capability block omits active member "${member.name}"`);
@@ -254,7 +303,7 @@ export function validateCastTree({ root, payloadPath }) {
   const active = parseRegistry(root, errors);
   const activeNames = new Set(active.map(({ name }) => name));
   const activeCharters = active.map(({ id }) => `.squad/agents/${id}/charter.md`);
-  const expectedPayload = new Set([...CORE_PAYLOAD, ...activeCharters]);
+  const expectedPayload = new Set([...CORE_PAYLOAD, ...activeCharters, ...REQUIRED_BUILTIN_CHARTERS]);
   for (const path of payload) {
     if (!expectedPayload.has(path)) errors.push(`payload: unexpected path ${path}`);
   }
@@ -275,10 +324,11 @@ export function validateCastTree({ root, payloadPath }) {
       .filter((entry) => statSync(join(agentsPath, entry)).isDirectory())
       .sort();
     const activeIds = active.map(({ id }) => id).sort();
-    if (JSON.stringify(materializedIds) !== JSON.stringify(activeIds)) {
+    const expectedIds = [...new Set([...activeIds, ...REQUIRED_BUILTIN_IDS])].sort();
+    if (JSON.stringify(materializedIds) !== JSON.stringify(expectedIds)) {
       errors.push(
-        `tree: materialized agent directories must exactly match active registry IDs `
-        + `(expected ${activeIds.join(', ')}, found ${materializedIds.join(', ')})`,
+        `tree: materialized agent directories must exactly match active registry IDs plus the `
+        + `four required built-ins (expected ${expectedIds.join(', ')}, found ${materializedIds.join(', ')})`,
       );
     }
   }
@@ -295,22 +345,51 @@ export function validateCastTree({ root, payloadPath }) {
     return errors;
   }
 
-  if (SUPPORT_ROLE_PATTERN.test(team)) {
-    errors.push('team: inactive/support roles must not be advertised by the GH-AW Cast roster');
+  const teamCharters = charterReferences(team);
+  const expectedTeamCharters = [...new Set([...activeCharters, ...REQUIRED_BUILTIN_CHARTERS])].sort();
+  if (JSON.stringify(teamCharters) !== JSON.stringify(expectedTeamCharters)) {
+    errors.push(
+      `team: charter references must exactly match active specialists plus the four required `
+      + `built-ins (expected ${expectedTeamCharters.join(', ')}, found ${teamCharters.join(', ')})`,
+    );
   }
-  if (SUPPORT_ROLE_PATTERN.test(coordinator)) {
-    errors.push('coordinator: inactive/support roles are forbidden in GH-AW Cast output');
+
+  const membersSection = extractSingleSection(team, '## Members', 'team', errors);
+  if (membersSection !== null) {
+    const leakedBuiltinCharters = charterReferences(membersSection)
+      .filter((reference) => REQUIRED_BUILTIN_CHARTERS.includes(reference));
+    if (leakedBuiltinCharters.length > 0) {
+      errors.push(`team: Members roster must not reference built-in charters: ${leakedBuiltinCharters.join(', ')}`);
+    }
+    const builtinRows = [...membersSection.matchAll(BUILTIN_NAME_ROW_PATTERN)].map((match) => match[1]);
+    if (builtinRows.length > 0) {
+      errors.push(`team: Members roster must not list built-in agents as specialists: ${[...new Set(builtinRows)].join(', ')}`);
+    }
   }
 
-  const teamCharters = extractLocalReferences(team)
-    .filter((reference) => /^\.squad\/agents\/[^/]+\/charter\.md$/.test(reference))
-    .sort();
-  if (JSON.stringify(teamCharters) !== JSON.stringify([...activeCharters].sort())) {
-    errors.push(
-      `team: charter references must exactly match active registry members `
-      + `(expected ${activeCharters.sort().join(', ')}, found ${teamCharters.join(', ')})`,
-    );
+  const builtinSection = extractSingleSection(team, BUILTIN_SECTION_HEADING, 'team', errors);
+  if (builtinSection !== null) {
+    const builtinSectionCharters = charterReferences(builtinSection);
+    if (JSON.stringify(builtinSectionCharters) !== JSON.stringify(REQUIRED_BUILTIN_CHARTERS)) {
+      errors.push(
+        `team: "${BUILTIN_SECTION_HEADING}" must reference exactly the four required built-in charters `
+        + `(expected ${REQUIRED_BUILTIN_CHARTERS.join(', ')}, found ${builtinSectionCharters.join(', ')})`,
+      );
+    }
+  }
+
+  const castSourcesSection = extractSingleSection(coordinator, CAST_SOURCES_HEADING, 'coordinator', errors);
+  if (castSourcesSection !== null) {
+    const castSourcesBuiltinCharters = charterReferences(castSourcesSection)
+      .filter((reference) => REQUIRED_BUILTIN_CHARTERS.includes(reference));
+    if (JSON.stringify(castSourcesBuiltinCharters) !== JSON.stringify(REQUIRED_BUILTIN_CHARTERS)) {
+      errors.push(
+        `coordinator: "${CAST_SOURCES_HEADING}" must reference exactly the four required built-in charters `
+        + `(expected ${REQUIRED_BUILTIN_CHARTERS.join(', ')}, found ${castSourcesBuiltinCharters.join(', ')})`,
+      );
+    }
   }
+  extractSingleSection(coordinator, BUILTIN_SECTION_HEADING, 'coordinator', errors);
 
   const routingRows = parseRouting(routing, activeNames, errors);
   validateCapabilities(coordinator, active, routingRows, errors);
diff --git a/workflows/squad.md b/workflows/squad.md
index 7338d84e8..7cae87d25 100644
--- a/workflows/squad.md
+++ b/workflows/squad.md
@@ -44,6 +44,10 @@ imports:
   - shared/squad-planning-policy.md
 resources:
   - shared/squad-cast-validator.mjs
+  - shared/builtins/scribe-charter.md
+  - shared/builtins/ralph-charter.md
+  - shared/builtins/rai-charter.md
+  - shared/builtins/fact-checker-charter.md
 tools:
   bash: true
   web-fetch:
@@ -51,6 +55,27 @@ tools:
     mode: gh-proxy
     toolsets: [default]
 steps:
+  - name: Materialize canonical built-in support agents
+    shell: bash
+    run: |
+      set -euo pipefail
+      builtins_src="${GITHUB_WORKSPACE:?}/.github/workflows/shared/builtins"
+      squad_agents="${GITHUB_WORKSPACE:?}/.squad/agents"
+      for pair in "scribe:Scribe" "ralph:Ralph" "rai:Rai" "fact-checker:Fact Checker"; do
+        id="${pair%%:*}"
+        display="${pair#*:}"
+        src="${builtins_src}/${id}-charter.md"
+        if [ ! -f "$src" ]; then
+          printf 'Canonical built-in charter resource is missing: %s\n' "$src" >&2
+          exit 1
+        fi
+        dest_dir="${squad_agents}/${id}"
+        mkdir -p "$dest_dir"
+        cp "$src" "${dest_dir}/charter.md"
+        if [ ! -f "${dest_dir}/history.md" ]; then
+          printf '# %s — History\n\n## Learnings\n\nInitial scaffold via gh-aw Cast. Ready for work.\n' "$display" > "${dest_dir}/history.md"
+        fi
+      done
   - name: Prepare deterministic Cast validator runner
     shell: bash
     run: |
@@ -96,7 +121,7 @@ steps:
       fi
       validator_script="$(cd "$(dirname "$validator_script")" && pwd -P)/$(basename "$validator_script")"
 
-      validator_expected_sha256="82aa5620d81e26513658fbde210b0f8d2ac3bc7572e672b421aaa17a2832e8cc"
+      validator_expected_sha256="5b8e1432de63c78488ee7ff6da4e67ea0c91044582109f678153c231704a0097"
       : > "$stderr_file"
       validator_actual_sha256="$(
         node -e 'const c=require("node:crypto"),f=require("node:fs");process.stdout.write(c.createHash("sha256").update(f.readFileSync(process.argv[1])).digest("hex"))' \
@@ -946,36 +971,47 @@ Guidelines: 4–7 active agents. Min: Lead + 2 specialists + 1 quality role.
 ##### Step 4: Generate Scaffolding
 
 The activation-time `squad init --preset default` team state is disposable input,
-not Cast PR payload. Determine the final selected IDs first, then completely
-replace the team-owned files below. Remove every bootstrap or prior
-`.squad/agents/{id}/` directory that is not in the final selected ID set; the
-default preset IDs are `lead`, `reviewer`, `security`, `docs`, and `devrel`
-(unless an ID was freshly selected and regenerated by this Cast). Do not reuse
-bootstrap routing, registry, history, or charters.
+not Cast PR payload. Determine the final selected specialist IDs first, then
+completely replace the team-owned files below. The **required built-in support
+set** is exactly `scribe`, `ralph`, `rai`, `fact-checker` — permanent, non-configurable,
+and always present regardless of naming mode or repo analysis; there is no
+mechanism to add, remove, rename, or extend this set. A prior deterministic
+workflow step already materialized `.squad/agents/{scribe,ralph,rai,fact-checker}/`
+verbatim from the canonical charter resources shipped with this workflow — never
+regenerate, edit, paraphrase, or reinterpret their charter content, and never
+delete those four directories. Preserve every directory in `{final selected
+specialist IDs} ∪ {scribe, ralph, rai, fact-checker}`. Remove every other
+bootstrap or prior `.squad/agents/{id}/` directory; the default preset IDs are
+`lead`, `reviewer`, `security`, `docs`, and `devrel` (unless an ID was freshly
+selected and regenerated by this Cast). Do not reuse bootstrap routing,
+registry, history, or charters, and never treat the four built-ins as part of
+the specialist registry, routing table, or specialist counts — they are
+mandatory support agents, separate from selected Cast specialists.
 
 Create/replace:
 
-1. **`.squad/team.md`** — Roster table containing only Coordinator (Squad), active registry Members (Name|Role|Charter path|Status), and Coding Agent (@copilot with `copilot-auto-assign: false`). Every charter path must be a concrete active-member path created by this Cast. Do not add inactive/support-role rows or charter references.
-2. **`.squad/agents/{id}/charter.md`** — Per agent: `# Name — Role`, Identity block (name, role, expertise, style), "What I Own", Boundaries (handle/don't), Model: auto.
-3. **`.squad/routing.md`** — Completely replace the file. It must contain exactly one `## Routing Table` section, using section heading `## Routing Table` and exact headers `Work Type | Route To | Examples`; every `Route To` value is an exact active casting-registry `persistent_name`, with multiple names comma-separated and no prose or annotations. No `## Work Type → Agent` section or other legacy routing section may remain anywhere in the file. Do not route to inactive/support roles.
-4. **`.squad/casting/registry.json`** — From Step 3.
+1. **`.squad/team.md`** — Roster table containing only Coordinator (Squad), active registry Members (Name|Role|Charter path|Status), and Coding Agent (@copilot with `copilot-auto-assign: false`). Every charter path must be a concrete active-member path created by this Cast. Do not add the four built-ins as Members rows or charter references there. Instead, add one dedicated `## Built-in Support Agents` section (separate from `## Members`) that lists exactly the four required built-ins — Scribe, Ralph, Rai, Fact Checker — each with its concrete canonical charter path (`.squad/agents/scribe/charter.md`, `.squad/agents/ralph/charter.md`, `.squad/agents/rai/charter.md`, `.squad/agents/fact-checker/charter.md`) and a one-line note that they are mandatory support agents, not Cast specialists and not routing destinations.
+2. **`.squad/agents/{id}/charter.md`** — Per selected specialist only: `# Name — Role`, Identity block (name, role, expertise, style), "What I Own", Boundaries (handle/don't), Model: auto. Never write, overwrite, or reinterpret `.squad/agents/scribe/charter.md`, `.squad/agents/ralph/charter.md`, `.squad/agents/rai/charter.md`, or `.squad/agents/fact-checker/charter.md` — those are the verbatim materialized resources from the prior deterministic step.
+3. **`.squad/routing.md`** — Completely replace the file. It must contain exactly one `## Routing Table` section, using section heading `## Routing Table` and exact headers `Work Type | Route To | Examples`; every `Route To` value is an exact active casting-registry `persistent_name`, with multiple names comma-separated and no prose or annotations. No `## Work Type → Agent` section or other legacy routing section may remain anywhere in the file. Do not route to the four built-ins or any other inactive/support role.
+4. **`.squad/casting/registry.json`** — From Step 3. Specialist entries only; never add scribe, ralph, rai, or fact-checker.
 5. **`.squad/casting/history.json`** — From Step 3.
 6. **`.squad/casting/policy.json`** — Standard policy with all 15 universes.
 7. **`.github/agents/squad.agent.md`** — Completely replace the disposable bootstrap coordinator. Do not reuse, patch, summarize, or retain any bootstrap body text. Generate a compact GH-AW-specific coordinator with this complete structure:
 
    - YAML frontmatter: `name: Squad`, a description that says it routes repository work to the active GH-AW Cast, and `tools: ["*"]`.
    - `# Squad Coordinator` plus one short paragraph establishing that the coordinator routes work and does not replace specialist judgment.
-   - `## Cast sources` listing only the concrete final Cast paths for the team, routing, registry, history, policy, meet-the-squad, and every active member charter. Do not use path globs or dynamic paths.
+   - `## Cast sources` listing only the concrete final Cast paths for the team, routing, registry, history, policy, meet-the-squad, every active specialist member charter, and the four built-in charter paths (`.squad/agents/scribe/charter.md`, `.squad/agents/ralph/charter.md`, `.squad/agents/rai/charter.md`, `.squad/agents/fact-checker/charter.md`). Do not use path globs or dynamic paths.
    - `## Routing work` with this behavior: read the routing table, select only active registry members, load only the selected member's charter, delegate through the platform's available agent mechanism, and synthesize the result for the user. If no route matches, choose the active Lead; if no active Lead exists, ask the user rather than inventing a member.
-   - One complete generated Team Capabilities block delimited by `<!-- SQUAD:TEAM-CAPABILITIES:BEGIN -->` and `<!-- SQUAD:TEAM-CAPABILITIES:END -->`. Preserve the stable heading, metadata, specialist table, supported task types, routing hints, and capability boundaries format. Set `specialists` to the active registry count and set both `taskTypes` and `hints` to the routing-row count; all three counts must be nonzero. Generate every value from the final team, routing, registry, and active charters.
+   - `## Built-in Support Agents` — concise operational instructions establishing that Scribe, Ralph, Rai, and Fact Checker are mandatory always-on support agents with a fixed lifecycle role (Scribe logs sessions and merges decisions silently in the background; Ralph monitors the work queue on request; Rai reviews for RAI/content-safety concerns and can gate on 🔴 Critical findings; Fact Checker verifies claims and offers Devil's-Advocate review before risky work ships). Never present them as selectable domain specialists, never list them as routing-table destinations, and never count them toward `specialists`, `taskTypes`, or `hints`.
+   - One complete generated Team Capabilities block delimited by `<!-- SQUAD:TEAM-CAPABILITIES:BEGIN -->` and `<!-- SQUAD:TEAM-CAPABILITIES:END -->`. Preserve the stable heading, metadata, specialist table, supported task types, routing hints, and capability boundaries format. Set `specialists` to the active registry count and set both `taskTypes` and `hints` to the routing-row count; all three counts must be nonzero and must never include the four built-ins. Generate every value from the final team, routing, registry, and active specialist charters.
 
-   The coordinator must be self-contained for the final Cast tree. It must not mention inactive/support roles, standalone lifecycle behavior, templates, configuration, decisions, plugins, logs, non-GH-AW clients, internal Squad source paths, or sample labels/names that are not active registry members.
+   The coordinator must be self-contained for the final Cast tree. It must not mention standalone lifecycle behavior, templates, configuration, decisions, plugins, logs, non-GH-AW clients, internal Squad source paths, or sample labels/names that are not active registry members. The four built-in charter references and the `## Built-in Support Agents` section are the one permitted exception to "no inactive/support roles" content — they are mandatory, not inactive, and must never be phrased as selectable specialists or routing destinations.
 
 Keep naming consistent across generated team state and the Cast PR summary. In descriptive mode, describe the choice as descriptive naming and never invent or mention a fictional universe.
 
 ##### Step 5: Generate meet-the-squad.md
 
-Create `meet-the-squad.md` at repo root with: title, naming mode (`Descriptive` in descriptive mode; otherwise the exact universe name), active team table (Name|Role|Specialty|How to talk), How to Work With Your Squad (label-based assignment with `9B8FCC` color, iteration commands, routing reference), "What Happened Here" block with analysis rationale (languages, structure, CI/CD, rationale), footer with cast date. Do not advertise inactive/support roles.
+Create `meet-the-squad.md` at repo root with: title, naming mode (`Descriptive` in descriptive mode; otherwise the exact universe name), active team table (Name|Role|Specialty|How to talk), How to Work With Your Squad (label-based assignment with `9B8FCC` color, iteration commands, routing reference), "What Happened Here" block with analysis rationale (languages, structure, CI/CD, rationale), footer with cast date. Do not advertise the four built-ins or any other inactive/support role as a selectable specialist.
 
 ##### Step 6: Build the Safe-Output Payload
 
@@ -987,7 +1023,11 @@ artifacts:
 - `.squad/casting/registry.json`
 - `.squad/casting/history.json`
 - `.squad/casting/policy.json`
-- only the concrete `.squad/agents/{selected-id}/charter.md` path for each final selected member
+- only the concrete `.squad/agents/{selected-id}/charter.md` path for each final selected specialist
+- `.squad/agents/scribe/charter.md`
+- `.squad/agents/ralph/charter.md`
+- `.squad/agents/rai/charter.md`
+- `.squad/agents/fact-checker/charter.md`
 - `.github/agents/squad.agent.md`
 - `meet-the-squad.md`
 
@@ -999,6 +1039,7 @@ Bootstrap default agent IDs `lead`, `reviewer`, `security`, `docs`, and `devrel`
 are excluded unless the final registry selected that ID and this Cast replaced
 its charter from scratch.
 
+
 ##### Step 7: Deterministic final-tree validation
 
 Natural-language review is not the gate. Immediately before requesting safe