Fix: FastAPI list parameter parsing in experimental OpenAPI parser #1834
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Resolves issue where FastAPI endpoints with list[T] parameters (e.g., `values: list[str]`)
generated empty input schemas, causing tools to be unusable.
The root cause was that FastAPI generates direct array schemas like:
```json
{
"type": "array",
"items": {"type": "string"},
"title": "Values"
}
```
But the schema combination logic only handled:
1. $ref schemas → single "body" property
2. Object schemas with properties → iterate properties
Added third case to handle direct array/primitive schemas by using the schema title
as the parameter name (e.g., "Values" → "values"), with fallback to generic names.
🤖 Generated with [Claude Code](https://claude.ai/code)
Co-authored-by: Jeremiah Lowin <[email protected]>
marvin-context-protocol
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| properties[param_name] = body_schema | ||
| if route.request_body.required: | ||
| required.append(param_name) | ||
| parameter_map[param_name] = {"location": "body", "openapi_name": param_name} |
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[P1] Prevent direct array body names from clobbering other parameters
The new branch that generates a parameter name for direct array/primitive request bodies writes the name straight into properties and parameter_map without checking for collisions with existing query/path/header parameters. When a route already has a parameter called the same as the array title (e.g. a query parameter values and a body schema titled Values), this code replaces the earlier entry so the combined schema loses the query parameter and parameter_map no longer contains it, meaning the request director cannot send that query parameter at all. The previous collision handling covers only object body properties, so this branch needs similar suffixing or uniqueness logic.
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|
@silb-saxobank this appears to resolve the example you provided in #1815 |
|
Tried this change locally and it does indeed seem to solve my issue. 😄 |
Resolves issue #1815 where FastAPI endpoints with list[T] parameters generated empty input schemas, causing tools to be unusable.
The root cause was that the schema combination logic didn't handle direct array schemas generated by FastAPI. Added support for these schemas with comprehensive test coverage.
🤖 Generated with Claude Code