fix(coderd/x/chatd): prevent nil required field in MCP tool schemas for OpenAI - #23538
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…or OpenAI
When an MCP server returns a tool whose inputSchema omits the
"required" field, the Go []string deserializes to nil. This nil
propagates through to the OpenAI API as "required": null, which
OpenAI rejects with "None is not of type 'array'".
Two fixes:
- mcpclient: coerce nil Required to []string{} in Info()
- chatloop: only include "required" key when non-empty
kylecarbs
marked this pull request as ready for review
March 24, 2026 21:53
ibetitsmike
approved these changes
Mar 24, 2026
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When an MCP server (e.g. Linear) returns a tool whose
inputSchemaomits therequiredfield, the Go[]stringdeserializes tonil. Thisnilpropagates through to the OpenAI API as"required": nullin JSON, which OpenAI rejects:Anthropic is unaffected because its provider defensively initializes
requiredto[]string{}. Fantasy's ownfuncToolWrapperalso has a nil guard, but the coder-sidemcpToolWrapperdid not.Two fixes:
Requiredto[]string{}inInfo(), matching what Fantasy'sfuncToolWrapperalready does."required"key in the schema map when non-empty, as defense-in-depth.