PRD: Squad TypeSpec Emitters — @bradygaster/typespec-squad + copilot (Phase 2 of #511) #517

PRD: Squad TypeSpec Emitters — @bradygaster/typespec-squad and @bradygaster/typespec-squad-copilot

Depends on: #511 (@agentspec/core must ship first)
Author: Dina's Squad (Flight, EECOM, CONTROL)
Status: Architecture complete, ready for implementation after #511 merges
Related: #485 (Agent Spec), #332 (A2A Protocol)

Problem

Squad's squad.config.ts → squad build → .squad/ pipeline works but is TypeScript-only. A TypeSpec-based definition would give compile-time validation, single-source-of-truth, and portability via @agentspec/core.

Solution — two packages

@bradygaster/typespec-squad — Squad extensions that inherit @agentspec/core

• Adds decorators: @casting (universe, castingName), @routing (pattern, agents, tier), @ceremony, @team
• Emits: charter.md, team.md, routing.md, casting/registry.json
• Peer depends on @agentspec/core

@bradygaster/typespec-squad-copilot — Copilot SDK target

• Adds decorators: @model (Copilot model selection)
• Emits: squad.config.ts, copilot-instructions.md, .github/agents/ governance
• Peer depends on @bradygaster/typespec-squad

Architecture

@agentspec/core (Phase 1, #511) | +-- @bradygaster/typespec-squad <- THIS ISSUE | Adds: @casting, @routing, @ceremony, @team | Emits: charter.md, team.md, routing.md | +-- @bradygaster/typespec-squad-copilot <- THIS ISSUE Adds: @model Emits: squad.config.ts, copilot-instructions.md

Key decisions (from team review)

• Casting stays in Squad layer (not base) — implementation flavor, not universal
• @model is Copilot-specific (not base or Squad)
• Parallel path to existing squad build — not a replacement
• tsp compile never embedded in squad build (no transitive dep on all users)
• Phase 2 generates AgentDefinition TypeScript type from TypeSpec into builders/generated/types.ts

Future emitters (documented, not built here)

• @bradygaster/typespec-squad-mcp — MCP server scaffolding
• @bradygaster/typespec-squad-a2a — A2A Agent Card and protocol types

Effort estimate

~2.5 weeks (corrected from 1.5 by EECOM review — sub-emitter split and squad.config.ts codegen add complexity)

Full PRD

Complete PRD v2 with test strategy, security requirements, and all 29 review items: .squad/decisions/inbox/pao-agentspec-typespec-prd-v2.md on the dev branch.

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