From 35e65339866f029c04e3e552619f2a74e83934c6 Mon Sep 17 00:00:00 2001
From: Hare <kei.hiracchi.0928@gmail.com>
Date: Sat, 20 Jun 2026 16:46:05 +0900
Subject: [PATCH] ticket: record mcp stdio lifecycle implementation report

---
 .yoi/tickets/00001KVHR3WRY/item.md   |  2 +-
 .yoi/tickets/00001KVHR3WRY/thread.md | 57 ++++++++++++++++++++++++++++
 2 files changed, 58 insertions(+), 1 deletion(-)

diff --git a/.yoi/tickets/00001KVHR3WRY/item.md b/.yoi/tickets/00001KVHR3WRY/item.md
index 2fccde95..bdb0c0ab 100644
--- a/.yoi/tickets/00001KVHR3WRY/item.md
+++ b/.yoi/tickets/00001KVHR3WRY/item.md
@@ -2,7 +2,7 @@
 title: 'MCP: implement stdio JSON-RPC lifecycle client'
 state: 'inprogress'
 created_at: '2026-06-20T05:30:04Z'
-updated_at: '2026-06-20T07:30:59Z'
+updated_at: '2026-06-20T07:45:58Z'
 assignee: null
 readiness: 'implementation_ready'
 risk_flags: ['mcp', 'stdio', 'json-rpc', 'process-lifecycle', 'diagnostics']
diff --git a/.yoi/tickets/00001KVHR3WRY/thread.md b/.yoi/tickets/00001KVHR3WRY/thread.md
index 70c3e0b9..bbcc4b37 100644
--- a/.yoi/tickets/00001KVHR3WRY/thread.md
+++ b/.yoi/tickets/00001KVHR3WRY/thread.md
@@ -110,3 +110,60 @@ Next action:
 - Wait for Coder implementation report, then inspect branch diff/validation evidence and route to Reviewer。
 
 ---
+
+<!-- event: implementation_report author: yoi-orchestrator at: 2026-06-20T07:45:58Z -->
+
+## Implementation report
+
+Coder implementation report received from `yoi-coder-00001KVHR3WRY`.
+
+Implementation commit:
+- `a114fa9d mcp: implement stdio lifecycle client`
+
+Changed areas reported:
+- Added new internal reusable crate `crates/mcp`。
+- Implemented stdio MCP lifecycle foundation:
+  - explicit resolved stdio server spec/config bridge from typed manifest MCP config。
+  - Tokio child process spawn with `stdin` / `stdout` / `stderr`。
+  - newline-delimited JSON-RPC request/response handling。
+  - `initialize` capability negotiation。
+  - `notifications/initialized`。
+  - bounded stdout/stderr/protocol payload handling。
+  - bounded/redacted stderr diagnostics。
+  - server-name + phase-aware errors。
+  - safe shutdown via stdin close, wait, terminate, and kill fallback。
+  - fail-closed server-to-client request handling including sampling/elicitation。
+- Added mock local stdio MCP server test binary scoped to `crates/mcp` tests。
+- Updated workspace membership and `package.nix` cargo hash。
+
+Coder validation reported:
+- `cargo test -p mcp`: passed。
+- `cargo check`: passed。
+- `cargo fmt --check`: passed。
+- `git diff --check`: passed。
+- `nix build .#yoi --no-link`: passed。
+
+Acceptance notes reported:
+- Mock stdio MCP server initializes successfully。
+- Initialize failure includes server name and `initialize` phase。
+- stderr diagnostics are bounded and secret/env values are redacted。
+- Shutdown is deterministic with terminate/kill fallback for uncooperative server。
+- Client capabilities do not advertise sampling or elicitation。
+- Server sampling requests receive JSON-RPC `-32601` fail-closed response。
+- No ToolRegistry/tool/resource/prompt registration was added。
+
+Known deferrals:
+- No MCP tools/resources/prompts exposure。
+- No remote MCP / Streamable HTTP / OAuth。
+- Downstream list/call/resource/prompt support remains for later Tickets。
+
+Orchestrator evidence checked before review dispatch:
+- Implementation worktree is clean。
+- HEAD is `a114fa9d`。
+- Diff from acceptance `c0e760d7..HEAD` is one implementation commit touching 8 files, about 1369 insertions / 1 deletion。
+- `git diff --check c0e760d7..HEAD` produced no diagnostics。
+
+Next action:
+- Dispatch Reviewer for r1 review against Ticket requirements, with focus on process lifecycle cleanup, JSON-RPC framing/bounds, stdout/stderr handling, secret redaction, sampling/elicitation fail-closed, no ToolRegistry/resources/prompts exposure, test determinism, and package/Nix impact。
+
+---