Fix Zod validation for non-string enums in OpenAPI parser#4
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ENG-9167 MCP server silently fails on OpenAPI endpoints with integer enums
The OpenAPI parser in |
mikesellitto
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amoses12,
another-yijiao,
dp-franklin and
emily-curry
February 18, 2026 21:30
emily-curry
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Feb 18, 2026
dp-franklin
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Feb 19, 2026
| return z.union( | ||
| schema.enum.map((val: any) => z.literal(val)) as [ | ||
| z.ZodLiteral<any>, | ||
| z.ZodLiteral<any>, |
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fyi: I assume that the z.union type requires at least two items in the array, but only one item is actually required at runtime. (0 will throw)
dp-franklin
approved these changes
Feb 19, 2026
z.enum() only accepts string values, so integer enums like visType: [0, 1, 2] on change request endpoints would fail validation before the request ever reached our api, producing a generic "tool execution failed" error. Now we use z.union of z.literal values for non-string enums instead.
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Currently, The OpenAPI parser in
src/parser.tsconverts all enum fields to z.enum(), which only supports string values. When the OpenAPI spec defines an non-string enum (i.e. visType with"type": "integer", "enum": [0, 1, 2]), the resulting Zod schema rejects every inputThis PR makes it so that we use
z.unionofz.literalvalues for non-string enums instead.Closes ENG-9167