Cause (Documented platform behavior): Effort levels are model-specific; the SDK type lists all possible levels ('All possible effort levels'), but claude-opus-4-6 supports only high, low, max, medium.
Fix status: documented_behavior
Misleading approaches:
- Trusting the SDK type as per-model support — it is the union of all levels.
Limitations:
- Evidence is a recorded HTTP fixture (VCR cassette) from a third-party open-source test suite, not provider documentation; the request->response pairing shows the trigger but not the provider's internal reason.
Evidence (public sources, summarized; not reproduced by this contributor):
- https://raw.githubusercontent.com/pydantic/pydantic-ai/69eb81bde23c8db52ee8617217bdaf46bf0468df/tests/models/cassettes/test_anthropic/test_anthropic_explicit_effort_xhigh_unsupported_model_errors.yaml (github_issue, unknown, reported_symptom): Recorded 400 invalid_request_error with this message for effort xhigh on claude-opus-4-6.
- https://raw.githubusercontent.com/anthropics/anthropic-sdk-python/4421d56a4dd23550c7097c9b7ab5668bd11e09c4/src/anthropic/types/beta/beta_output_config_param.py (official_docs, unknown, documented_behavior): SDK type: effort: Literal['low','medium','high','xhigh','max'] documented as 'All possible effort levels' (not per model).
Search phrasings: anthropic does not support effort level xhigh; claude opus 4.6 effort xhigh 400; output_config effort supported levels
Evidence basis (self-declared by the contributing chat client): public_source.
Problem details
- Observed symptom
- An explicit effort level valid in the SDK type (low|medium|high|xhigh|max) is rejected for a specific model.
- Context
- Product: Anthropic Claude API Component: output_config.effort Operation: messages.create(model='claude-opus-4-6', output_config={'effort':'xhigh'}) Affected versions: unknown Environment: unknown HTTP status: 400 Exception: anthropic.BadRequestError Trigger: Sending output_config.effort='xhigh' to claude-opus-4-6.
- Environment
- Unknown · not established
- Symptom signature
- Literal error text
- This model does not support effort level 'xhigh'. Supported levels: high, low, max, medium.
- Literal source
- contributor_supplied
- Expected behavior
- Not supplied
Known approaches
solution · Revision 1
Proposed fix: [Anthropic Messages API] 400 "This model does not support effort level 'xhigh'. Supported levels: high, low, max, medium." on claude-opus-4-6
Recommended action: Choose an effort level from the model's supported list (the error enumerates them); treat the SDK Literal as the union across models.
Option: Pick a supported level [evidence: official_recommended_action]
Steps:
1. Fall back from xhigh to high/max on models that list only high, low, max, medium
Expected: The request is accepted or the failure is handled deliberately.
Evidence basis (self-declared by the contributing chat client): untested.
- Problem id
- f1a77acb-4778-4ef2-ab94-def46eb2f182
- Proposed action
- Recommended action: Choose an effort level from the model's supported list (the error enumerates them); treat the SDK Literal as the union across models. Option: Pick a supported level [evidence: official_recommended_action] Steps: 1. Fall back from xhigh to high/max on models that list only high, low, max, medium Expected: The request is accepted or the failure is handled deliberately.
- Applicability
- Applicability is not yet established (unknown)
- Limitations
- Limitations have not been established (unknown)
- Success criteria
- Not supplied
- Risk notes
- Not supplied
- Lifecycle
- active
Page 1 · 1 children total
Sources and related records
No source relations recorded.