fix: allow casting runtime state writes

.changeset/casting-runtime-state.md

@@ -0,0 +1,6 @@
+---
+'@bradygaster/squad-cli': patch
+'@bradygaster/squad-sdk': patch
+---
+
+Allow the casting policy, registry, and history to be persisted through runtime state tools.

packages/squad-sdk/src/tools/index.ts

@@ -255,10 +255,17 @@ function normalizeStateToolDir(dir?: string): string {
   return normalized;
 }
 
+const MUTABLE_CASTING_STATE_KEYS = new Set([
+  'casting/policy.json',
+  'casting/registry.json',
+  'casting/history.json',
+]);
+
 function validateMutableStateToolKey(key: string): void {
   const isMutable =
     key === 'decisions.md' ||
     key.startsWith('decisions/inbox/') ||
+    MUTABLE_CASTING_STATE_KEYS.has(key) ||
     /^agents\/[a-zA-Z0-9_-]+\/history\.md$/.test(key) ||
     key.startsWith('log/') ||
     key.startsWith('orchestration-log/') ||
@@ -268,7 +275,7 @@ function validateMutableStateToolKey(key: string): void {
 
   if (!isMutable) {
     throw new Error(
-      'State mutations are limited to mutable runtime state (decisions, inbox, logs, sessions, scratch files, agent history, and identity). Static config such as config.json, team.md, routing.md, charters, templates, and skills must not be changed with state tools.',
+      'State mutations are limited to mutable runtime state (decisions, inbox, casting policy/registry/history, logs, sessions, scratch files, agent history, and identity). Static config such as config.json, team.md, routing.md, charters, templates, and skills must not be changed with state tools.',
     );
   }
 }

test/cli/state-mcp.test.ts

@@ -19,14 +19,14 @@ function git(args: string): string {
   return execSync(`git ${args}`, { cwd: TMP, encoding: 'utf-8', stdio: ['pipe', 'pipe', 'pipe'] }).trim();
 }
 
-function initTwoLayerSquad(): void {
+function initSquad(stateBackend: 'orphan' | 'two-layer'): void {
   mkdirSync(join(TMP, '.squad'), { recursive: true });
-  writeFileSync(join(TMP, '.squad', 'config.json'), JSON.stringify({ stateBackend: 'two-layer' }, null, 2));
+  writeFileSync(join(TMP, '.squad', 'config.json'), JSON.stringify({ stateBackend }, null, 2));
   writeFileSync(join(TMP, 'README.md'), '# state mcp test\n');
   git('init');
   git('config user.email "test@test.com"');
   git('config user.name "Test"');
-  git('add .');
+  git('add README.md .squad/config.json');
   git('commit -m "init"');
 }
 
@@ -40,7 +40,6 @@ describe('state-mcp bridge', () => {
   beforeEach(() => {
     if (existsSync(TMP)) rmSync(TMP, { recursive: true, force: true });
     mkdirSync(TMP, { recursive: true });
-    initTwoLayerSquad();
   });
 
   afterEach(() => {
@@ -49,6 +48,7 @@ describe('state-mcp bridge', () => {
   });
 
   it('lists Squad state tools for MCP clients', async () => {
+    initSquad('two-layer');
     const messages: JsonRpcMessage[] = [];
     const session = createStateMcpSession(TMP, message => messages.push(message as JsonRpcMessage));
 
@@ -63,6 +63,7 @@ describe('state-mcp bridge', () => {
   });
 
   it('writes and reads two-layer state without mutating the worktree .squad files', async () => {
+    initSquad('two-layer');
     const messages: JsonRpcMessage[] = [];
     const session = createStateMcpSession(TMP, message => messages.push(message as JsonRpcMessage));
 
@@ -92,4 +93,48 @@ describe('state-mcp bridge', () => {
     expect(existsSync(join(TMP, '.squad', 'decisions', 'inbox', 'mcp-proof.md'))).toBe(false);
     expect(readFileSync(join(TMP, '.squad', 'config.json'), 'utf8')).toContain('two-layer');
   });
+
+  it.each(['orphan', 'two-layer'] as const)(
+    'writes all casting runtime state keys through the %s backend',
+    async (stateBackend) => {
+      initSquad(stateBackend);
+      const messages: JsonRpcMessage[] = [];
+      const session = createStateMcpSession(TMP, message => messages.push(message as JsonRpcMessage));
+      const castingState = [
+        ['casting/policy.json', '{"mode":"auto"}\n'],
+        ['casting/registry.json', '{"agents":{}}\n'],
+        ['casting/history.json', '{"events":[]}\n'],
+      ] as const;
+
+      for (const [key, content] of castingState) {
+        const writeIndex = messages.length;
+        await session.handleRequest({
+          jsonrpc: '2.0',
+          id: `write-${key}`,
+          method: 'tools/call',
+          params: {
+            name: 'squad_state_write',
+            arguments: { key, content },
+          },
+        });
+        expect(resultAsRecord(messages[writeIndex]!)['isError']).not.toBe(true);
+
+        const readIndex = messages.length;
+        await session.handleRequest({
+          jsonrpc: '2.0',
+          id: `read-${key}`,
+          method: 'tools/call',
+          params: {
+            name: 'squad_state_read',
+            arguments: { key },
+          },
+        });
+        expect(resultAsRecord(messages[readIndex]!)['content']).toEqual([{ type: 'text', text: content }]);
+        expect(existsSync(join(TMP, '.squad', ...key.split('/')))).toBe(false);
+      }
+
+      expect(git('status --porcelain')).toBe('');
+    },
+    30_000,
+  );
 });

test/state-backend.test.ts

@@ -757,6 +757,30 @@ describe('ToolRegistry state tools with git-native backend', () => {
     expect(backend.read('sessions/session-1/state.md')).toBeUndefined();
   });
 
+  it('allows exactly the three casting runtime state keys', { timeout: 30_000 }, async () => {
+    const backend = new OrphanBranchBackend(TMP);
+    const adapter = new StateBackendStorageAdapter(backend, squadDir());
+    const registry = new ToolRegistry(squadDir(), undefined, adapter);
+    const write = registry.getTool('squad_state_write')!;
+
+    const castingKeys = [
+      'casting/policy.json',
+      'casting/registry.json',
+      'casting/history.json',
+    ];
+    for (const key of castingKeys) {
+      await expect(write.handler({ key, content: '{}\n' })).resolves.toMatchObject({ resultType: 'success' });
+      expect(backend.read(key)).toBe('{}\n');
+      expect(existsSync(join(squadDir(), key))).toBe(false);
+    }
+
+    await expect(write.handler({ key: 'casting/agents.json', content: '{}\n' })).resolves.toMatchObject({ resultType: 'failure' });
+    await expect(write.handler({ key: 'casting/archive/history.json', content: '{}\n' })).resolves.toMatchObject({ resultType: 'failure' });
+    expect(backend.read('casting/agents.json')).toBeUndefined();
+    expect(backend.read('casting/archive/history.json')).toBeUndefined();
+    expect(git('status --porcelain')).toBe('');
+  });
+
   it('routes existing squad_decide writes through configured backend storage', { timeout: 20_000 }, async () => {
     const backend = new OrphanBranchBackend(TMP);
     const adapter = new StateBackendStorageAdapter(backend, squadDir());