Phase 5: Harness Adapters #18

Phase 5: Harness Adapters

Implement the adapter pattern for all 5 supported harnesses (Claude Code, Codex CLI, OpenCode, Pi Agent, Antigravity) plus the base interface.

Tasks

• Task 15: Implement base harness adapter interface — Create harness-adapter.ts with abstract base class or interface. Define methods: getMcpConfigPath(), getSkillsPath(), readMcpConfig(), writeMcpConfig(), supportsMcp(). Create adapter factory function.

  • Depends on: Task 4
  • Files: packages/core/src/harnesses/harness-adapter.ts, packages/core/src/harnesses/index.ts
  • Testing: Type checking to ensure all adapters implement interface.

• Task 16: Implement Claude Code adapter — Config path: ~/.claude.json (user-scoped MCP config). Skills path: ~/.claude/skills/. JSON format. Supports MCP: true.

  • Depends on: Task 15
  • Files: packages/core/src/harnesses/claude-adapter.ts
  • Testing: Unit tests for path resolution, config read/write with JSON format.

• Task 17: Implement Codex CLI adapter — Config path: ~/.codex/config.toml. Skills path: ~/.codex/skills/. TOML format. Supports MCP: true.

  • Depends on: Task 15
  • Files: packages/core/src/harnesses/codex-adapter.ts
  • Testing: Unit tests for path resolution, config read/write with TOML format.

• Task 18: Implement OpenCode adapter — Config path: ~/.config/opencode/opencode.jsonc. Skills path: ~/.config/opencode/skills/. JSONC format (JSON with comments). Supports MCP: true.

  • Depends on: Task 15
  • Files: packages/core/src/harnesses/opencode-adapter.ts
  • Testing: Unit tests for path resolution, config read/write with JSONC format (preserve comments).

• Task 19: Implement Pi Agent adapter — No MCP config path (returns null). Skills path: ~/.pi/agent/skills/. Note: Pi also reads from ~/.agents/skills/ natively. Supports MCP: false. Skip MCP configuration in install flow.

  • Depends on: Task 15
  • Files: packages/core/src/harnesses/pi-adapter.ts
  • Testing: Unit tests for path resolution, verify supportsMcp() returns false.

• Task 19b: Implement Antigravity adapter — Config path: ~/.gemini/antigravity-cli/mcp_config.json. Skills path: ~/.gemini/antigravity-cli/skills/. JSON format. Supports MCP: true. Export from packages/core/src/harnesses/index.ts.

  • Depends on: Task 15
  • Files: packages/core/src/harnesses/antigravity-adapter.ts, packages/core/src/harnesses/index.ts
  • Testing: Unit tests for path resolution, config read/write with JSON format.