fix(llm): handle LiteLLM supports_response_schema introspection failure gracefully (#6412)

[Hasnaathussain]

Pull Request Description

Description

Closes #6412

This PR resolves an issue in LLM._validate_call_params() where unhandled LiteLLM introspection failures in supports_response_schema() would cause _validate_call_params() to crash or skip parameter validation.

Root Cause

In crewai/llm.py, _validate_call_params() invoked supports_response_schema() directly without exception handling. If LiteLLM failed to introspect an unmapped/custom model ID or raised an exception, _validate_call_params() crashed unhandled.

Proposed Changes

1. Added exception handling around supports_response_schema() in _validate_call_params(), mirroring the pattern used in supports_function_calling().
2. On LiteLLM introspection errors, the failure is logged at DEBUG level and is_supported defaults to True (permitting modern models and proxies with custom model names to execute).
3. Added unit test test_validate_call_params_handles_introspection_error() in lib/crewai/tests/test_llm.py.

Testing

• Verified test_validate_call_params_handles_introspection_error passes.
• Verified linting and formatting with ruff check and ruff format.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro Plus

Run ID: ee9c425f-2799-495a-89c1-d28a33a412c0

📥 Commits

Reviewing files that changed from the base of the PR and between ce739e2 and 5c61444.

📒 Files selected for processing (2)

• lib/crewai/src/crewai/llm.py
• lib/crewai/tests/test_llm.py

---

📝 Walkthrough

Walkthrough

_validate_call_params now skips validation without a response format, tolerates LiteLLM schema introspection errors, and raises only for confirmed unsupported combinations. A unit test covers the introspection-error path.

Changes

Response format validation

Layer / File(s)	Summary
Guarded response-format validation and regression coverage lib/crewai/src/crewai/llm.py, lib/crewai/tests/test_llm.py	_validate_call_params handles missing formats and schema-check exceptions, while unsupported models still raise ValueError; a unit test verifies introspection failures do not propagate.

Suggested reviewers: lorenzejay, greysonlalonde

🚥 Pre-merge checks | ✅ 3 | ❌ 2

❌ Failed checks (2 warnings)

Check name	Status	Explanation	Resolution
Linked Issues check	⚠️ Warning	The change appears to fix the crash, but it doesn't show that get_capabilities fallback or reasoning_effort validation still run as required.	Ensure static capability checks run even when LiteLLM introspection fails, and add tests for response_format and reasoning_effort fallback coverage.
Docstring Coverage	⚠️ Warning	Docstring coverage is 66.67% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (3 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly describes the LiteLLM introspection failure fix.
Description check	✅ Passed	The description matches the bug fix and added test described in the changes.
Out of Scope Changes check	✅ Passed	Only the LLM validation code and a focused unit test were changed, which fits the stated bug fix.

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests

---

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

_{Comment @coderabbitai help to get the list of available commands.}