fix(mcp): keep stdio child no-proxy entries runtime-safe#2081
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| function usesNodeEnvProxy(command: string, args: readonly string[]): boolean { | ||
| const executable = command.split(/[\\/]/).at(-1) ?? ''; | ||
| if (NODE_ENV_PROXY_COMMAND_RE.test(executable)) return true; | ||
| return NODE_ENV_PROXY_WRAPPER_RE.test(executable) && args.some((arg) => NODE_ENV_PROXY_ARGUMENT_RE.test(arg)); |
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A stdio server started through an extensionless Node bin (for example command: "./node_modules/.bin/my-mcp" or a globally installed MCP executable) inherits NODE_USE_ENV_PROXY=1, but its command does not match either regex and is therefore treated as a non-Node runtime. The new code removes [::1], so that Node child loses the IPv6 loopback proxy bypass that this change is intended to preserve; any such server that connects to http://[::1]:<port> under an HTTP proxy will attempt the proxy instead. This classifier is duplicated in the v2 client as well, so both engines need a way to preserve the entry for Node shebang/bin launchers.
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Related Issue
Fixes #1931
Problem
When an HTTP proxy is configured, stdio MCP children inherit
[::1]in bothNO_PROXYcasings. Pythonhttpxtreats that entry as an invalid port and exits before the MCP handshake. Removing it unconditionally would instead regress Node's IPv6 loopback bypass whenNODE_USE_ENV_PROXY=1.What changed
[::1]for direct and commonly wrapped Node launchers and JavaScript entry points::1form for other runtimes, while honoring explicit parent or per-server bracketed overridesNo documentation update is needed because the public proxy configuration and precedence are unchanged.
Testing
pnpm exec vitest run test/mcp/client-stdio.test.tsinpackages/agent-core— 29 passedpnpm exec vitest run test/agent/mcp/client-stdio.test.tsinpackages/agent-core-v2— 20 passedpnpm --filter @moonshot-ai/agent-core test— 3,990 passed, 3 expected failures, 30 skipped, 1 todopnpm --filter @moonshot-ai/agent-core-v2 test— 3,958 passedpnpm lint— 0 errors (existing warnings only)httpx.Client()reproducer — bracketed child value fails; portable child value succeeds200 ok; bare value attempts the proxy and failsChecklist
gen-changesetsskill, or this PR needs no changeset.gen-docsskill, or this PR needs no doc update.