Claude Code / AI Coding Tools

Claude Code MCP STDIO subprocess reaped mid-conversation without shutdown signal

Users running Claude Code with MCP STDIO-based tools experience server processes getting OS-reaped during conversations, then respawned without graceful shutdown, causing hung connections and tool failures. Includes evidence for Claude Code troubleshooting demand.

Source-backed Last updated May 21, 2026 1 source Needs local verification

Category: AI Coding Tools
Error signature: MCP STDIO subprocess reaped + respawned mid-conversation, no shutdown signal to the server
Quick fix: Compare the failing environment with a known working setup, then change one configuration value at a time.
Updated: May 21, 2026
Verification status: Source-backed
Evidence: 1 public source URL

Before you change production

This page includes public source URLs in the imported troubleshooting record. Compare those references with your version and environment before applying changes.

Reproduce the smallest failing action and save non-secret logs before changing configuration.
Check versions for Claude Code, related SDKs, package managers, CI runners, and hosting providers.
Change one setting or dependency at a time, then rerun the same failing command or request.
Avoid destructive commands, credential rotation, billing changes, or security relaxations without a rollback plan.

What this error means

MCP STDIO subprocess reaped + respawned mid-conversation, no shutdown signal to the server is a Claude Code failure pattern reported for developers trying to users running claude code with mcp stdio-based tools experience server processes getting os-reaped during conversations, then respawned without graceful shutdown, causing hung connections and tool failures.. Based on the imported evidence, treat this as a tool-specific troubleshooting page rather than a generic API error.

Why this happens

Source: anthropics/claude-code#61146 (opened May 21, 2026, today — very recent). Labeled area:mcp and bug. MCP servers use STDIO transport; when parent process signals cause SIGTERM/SIGKILL, child servers restart without prior termination handshake. Affects developers relying on custom MCP tools (GitHub, databases, etc.) within Claude Code sessions. Category: AI Coding Tools — MCP auth/tool integration.

Common causes

Source: anthropics/claude-code#61146 (opened May 21, 2026, today — very recent). Labeled area:mcp and bug. MCP servers use STDIO transport; when parent process signals cause SIGTERM/SIGKILL, child servers restart without prior termination handshake. Affects developers relying on custom MCP tools (GitHub, databases, etc.) within Claude Code sessions. Category: AI Coding Tools — MCP auth/tool integration.

Quick fixes

Confirm the exact error signature matches MCP STDIO subprocess reaped + respawned mid-conversation, no shutdown signal to the server.
Check the Claude Code account, local tool state, and provider configuration involved in the failing workflow.
Compare the failing environment with a known working setup, then change one configuration value at a time.

Platform/tool-specific checks

Verify the command, editor, extension, or API client that produced the error.
Compare local settings with CI, deployment, or editor-level settings when the error appears in only one environment.
Avoid deleting credentials, local model data, or project settings until the failing scope is clear.

Step-by-step troubleshooting

Capture the exact error message and the command, editor action, or request that triggered it.
Check whether the failure is account/auth, quota/rate, model/provider, local runtime, or deployment configuration.
Review the source evidence below and compare it with your environment.
Apply one change at a time and rerun the smallest failing action.
Keep the working fix documented for the team or deployment environment.

How to prevent it

Keep provider/tool configuration documented.
Record non-secret diagnostics such as tool version, provider name, model name, and command path.
Add a lightweight check before CI or production workflows depend on the tool.

Diagnostic flow for this page

Match MCP STDIO subprocess reaped + respawned mid-conversation, no shutdown signal to the server exactly before applying the quick fix.
Compare the failing environment with Claude Code versions, account scope, provider settings, and deployment context.
Check the listed common causes in order, starting with the cause that best matches your logs.
Use the evidence status below to decide whether to confirm against public sources or official documentation.
Apply one reversible change, rerun the smallest failing action, and keep rollback notes.

FAQ

What does MCP STDIO subprocess reaped + respawned mid-conversation, no shutdown signal to the server mean in Claude Code?

MCP STDIO subprocess reaped + respawned mid-conversation, no shutdown signal to the server indicates the workflow described by "Claude Code MCP STDIO subprocess reaped mid-conversation without shutdown signal" failed in a AI Coding Tools context. Start by confirming the exact signature and the component that emitted it.

What should I check first for MCP STDIO subprocess reaped + respawned mid-conversation, no shutdown signal to the server?

Check whether this cause matches your environment: Source: anthropics/claude-code#61146 (opened May 21, 2026, today — very recent). Labeled area:mcp and bug. MCP servers use STDIO transport; when parent process signals cause SIGTERM/SIGKILL, child servers restart without prior termination handshake. Affects developers relying on custom MCP tools (GitHub, databases, etc.) within Claude Code sessions. Category: AI Coding Tools — MCP auth/tool integration.

Is the MCP STDIO subprocess reaped + respawned mid-conversation, no shutdown signal to the server guidance source-backed?

The "Claude Code MCP STDIO subprocess reaped mid-conversation without shutdown signal" page is labeled source-backed. It has 1 public source URL from github.com, so use that evidence status when deciding how much additional verification you need.

When should I avoid the quick fix for MCP STDIO subprocess reaped + respawned mid-conversation, no shutdown signal to the server?

For "Claude Code MCP STDIO subprocess reaped mid-conversation without shutdown signal", avoid applying "Compare the failing environment with a known working setup, then change one configuration value at a time." when the error text differs, the affected version or provider is different, or the change would touch credentials, billing, DNS, production deploy settings, or irreversible data.

What should I collect before debugging MCP STDIO subprocess reaped + respawned mid-conversation, no shutdown signal to the server?

For "Claude Code MCP STDIO subprocess reaped mid-conversation without shutdown signal", collect the failing Claude Code command or request, non-secret configuration, versions, timestamps, request IDs when available, and the smallest reproduction that still triggers the signature.