fix(mcp): sanitize bridged tool names to the API charset#2285
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MCP tools whose names contain characters outside the OpenAI/DeepSeek function-name charset (e.g. unity/health) were sent to the API verbatim and rejected with a 400, making the whole server unusable. Sanitize the model-facing/registered name to [a-zA-Z0-9_-] (64-char cap) at the single registration chokepoint. The bridge closure still calls the server with the original name, so no reverse mapping is needed. Sanitized names that collide get a numeric suffix and a startup warning.
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What
Sanitizes bridged MCP tool names to the OpenAI/DeepSeek function-name charset (
[a-zA-Z0-9_-], 64-char cap) at the single registration chokepoint inregisterSingleMcpTool. The bridge closure still dispatches to the server with the original name, so no reverse mapping is needed. Sanitized names that collide get a numeric suffix and a startup warning.Why
MCP servers whose tools are named with characters outside the API charset — e.g.
unity/health,unity/changes/applyfrom a Unity MCP bridge — were sent to the DeepSeek API verbatim and rejected with a 400 before the agent loop could run, making the entire server unusable.The bridge already separates the model-facing/registered name from the server-side name (the dispatch closure captures the original
stableTool.name), so the fix only needs to make the registered name API-safe; dispatch is untouched.Verified end-to-end against a live Unity MCP (streamable HTTP): tools bridge with rename notices (
unity/health→unity_health), the model calls the sanitized name, and Unity receives the original endpoint.How to verify
npm run verify(lint + typecheck + tests + comment-policy gate) — passes locally.tests/mcp-registered-name-sanitize.test.tscovers:/sanitized, dispatch hits the original endpoint, not the sanitized name (the key regression guard), collision auto-suffix, charset/length invariant, and no-op for already-valid names.Checklist
npm run verifypasses locally (lint + typecheck + tests + comment-policy gate)Co-Authored-By: Claudetrailer in commitsCHANGELOG.md— release notes are maintainer-written at release time