# MCP Round 4 Plan
## Summary
Round 4 expands `spool-mcp` from lifecycle-only tooling into a retrieval gateway that exposes the existing context and wakeup core through MCP.
The work is sequenced in this order:
1. add retrieval MCP tools on top of `app` and `memory_gateway`
2. keep response payloads structured and aligned with existing domain objects
3. verify both lifecycle and retrieval tools through the same MCP server
## Key Changes
### Retrieval tools
- add `memory_search`
- add `memory_explain`
- add `memory_wakeup`
- reuse existing route input concepts:
- `task`
- `cwd`
- optional `files`
- optional `target`
- optional `format`
- optional `profile` for wakeup
### MCP server shape
- keep a single `spool-mcp` binary
- continue using newline-delimited JSON-RPC over stdio
- keep lifecycle and retrieval tools in one shared tool registry
## Test Plan
- handler tests for retrieval tools
- process smoke test covering:
- `initialize`
- `tools/list`
- lifecycle tool call
- retrieval tool call
## Assumptions
- this round does not rename existing lifecycle tool names
- this round does not add MCP prompts/resources
- this round does not add write metadata yet
## Completion Status
Last checked: `2026-04-11`
Completed in this round:
- added retrieval MCP tools:
- `memory_search`
- `memory_explain`
- `memory_wakeup`
- kept lifecycle and retrieval tools on the same MCP server
- added retrieval handler coverage and expanded MCP smoke coverage
- verification completed with full test and check passes
Checked for omissions against this plan:
- no missed items inside the scoped implementation baseline
- lifecycle tool names remain unchanged
- MCP prompts/resources remain intentionally deferred
- write metadata remains intentionally deferred