fix: bedrock stop reason

[TejasGhatte]

Summary

Stop reason normalization was inconsistent across the Bedrock and Anthropic providers. Unknown or unmappable stop reasons (e.g. guardrail_intervened) were silently coerced to "stop", and the Responses API path for Bedrock was not applying any stop reason conversion at all. This PR fixes both issues and adds a proper reverse mapping for converting Bifrost stop reasons back to Bedrock format.

Changes

• guardrail_intervened no longer maps to content_filter — it passes through as-is since there is no clean semantic equivalent in the Bifrost format.
• Unknown stop reasons now pass through unchanged instead of defaulting to "stop".
• Added convertBifrostToBedrockStopReason and a bifrostToBedrockStopReason reverse lookup map to support converting Bifrost stop reasons back to Bedrock format.
• BedrockConverseResponse.ToBifrostResponsesResponse now applies stop reason conversion via convertBedrockStopReason, which was previously missing.
• ToBedrockConverseResponse now prioritizes StopReason over IncompleteDetails when deriving the Bedrock stop reason.
• AnthropicMessageResponse.ToBifrostResponsesResponse now uses ConvertAnthropicFinishReasonToBifrost instead of passing the raw Anthropic stop reason string through.
• Added TestBedrockStopReasonMappingResponsesPath and TestBifrostToBedrockStopReasonReverseMapping to cover the Responses API path and reverse mapping behavior.

Type of change

• Bug fix
• Feature
• Refactor
• Documentation
• Chore/CI

Affected areas

• Core (Go)
• Transports (HTTP)
• Providers/Integrations
• Plugins
• UI (React)
• Docs

How to test

go test ./core/providers/bedrock/... ./core/providers/anthropic/...

Expected: all existing and new tests pass, including TestBedrockStopReasonMapping, TestBedrockStopReasonMappingResponsesPath, and TestBifrostToBedrockStopReasonReverseMapping.

Breaking changes

• Yes
• No

guardrail_intervened previously mapped to content_filter in Bedrock stop reason normalization. It now passes through as guardrail_intervened. Consumers relying on the old mapping will need to handle this value explicitly.

Related issues

Security considerations

None.

Checklist

• I read docs/contributing/README.md and followed the guidelines
• I added/updated tests where appropriate
• I updated documentation where needed
• I verified builds succeed (Go and UI)
• I verified the CI pipeline passes locally if applicable

[CLAassistant]

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[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

Run ID: 91346463-c301-4dcf-8964-c0ac7450783a

📥 Commits

Reviewing files that changed from the base of the PR and between f4bd3f6 and f231f09.

📒 Files selected for processing (4)

• core/providers/anthropic/responses.go
• core/providers/bedrock/bedrock_test.go
• core/providers/bedrock/responses.go
• core/providers/bedrock/utils.go

🚧 Files skipped from review as they are similar to previous changes (4)

• core/providers/anthropic/responses.go
• core/providers/bedrock/responses.go
• core/providers/bedrock/bedrock_test.go
• core/providers/bedrock/utils.go

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📝 Walkthrough

Summary by CodeRabbit

• Bug Fixes

  • Improved stop-reason mapping across AI providers (Anthropic and Bedrock) for more accurate termination reporting.
  • Preserve unknown pass-through reasons and correct guardrail/content-filter normalization; explicit stop-reasons now take priority when present.

• Tests

  • Added and expanded test coverage for stop-reason normalization and reverse-conversion scenarios.

Walkthrough

Stop-reason handling was unified: Bedrock and Anthropic providers now convert known finish reasons via explicit mapping functions, unmapped reasons pass through unchanged, and tests were added/updated to verify forward and reverse mappings and precedence rules.

Changes

Stop-Reason Conversion Unification

Layer / File(s)	Summary
Bedrock stop-reason conversion utilities core/providers/bedrock/utils.go	bedrockFinishReasonToBifrost mapping table updated to omit guardrail_intervened→content_filter; added bifrostToBedrockStopReason reverse map; unmapped reasons now passthrough instead of defaulting to "stop".
Bedrock response handlers core/providers/bedrock/responses.go	Stream and Converse conversions delegate stop-reason mapping to convertBedrockStopReason; ToBedrockConverseResponse now prefers bifrostResp.StopReason (converted) over IncompleteDetails.Reason, then tool_use, then end_turn.
Anthropic response conversion core/providers/anthropic/responses.go	ToBifrostResponsesResponse sets bifrostResp.StopReason via ConvertAnthropicFinishReasonToBifrost(response.StopReason) instead of raw string casting.
Stop-reason conversion tests core/providers/bedrock/bedrock_test.go	Updated TestBedrockStopReasonMapping expectations; added TestBedrockStopReasonMappingResponsesPath and TestBifrostToBedrockStopReasonReverseMapping to cover Responses-path mapping, reverse mapping, and precedence/passthrough behaviors.

🎯 3 (Moderate) | ⏱️ ~20 minutes

Suggested reviewers:

• akshaydeo

"I hopped through mappings, neat and spry,
Unknown reasons pass on by,
Bedrock, Anthropic—both in tune,
Tests now sing a steady tune,
A rabbit's cheer for refactor boon!" 🐇

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 75.00% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title 'fix: bedrock stop reason' is concise and clearly identifies the primary change—a bug fix addressing Bedrock stop reason handling inconsistencies.
Description check	✅ Passed	The description comprehensively covers all template sections with clear explanations of the problem, changes made, affected areas, testing instructions, and breaking changes.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

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✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch 05-14-fix_bedrock_stop_reason

Warning

There were issues while running some tools. Please review the errors and either fix the tool's configuration or disable the tool if it's a critical failure.

🔧 golangci-lint (2.12.2)

level=error msg="[linters_context] typechecking error: pattern ./...: directory prefix . does not contain main module or its selected dependencies"

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[TejasGhatte]

• fix: bedrock stop reason #3506 👈 (View in Graphite)
• dev

This stack of pull requests is managed by Graphite. Learn more about stacking.

[greptile-apps]

Confidence Score: 5/5

Safe to merge — all changes are narrowly scoped stop reason normalization fixes with good test coverage on the main paths.

The logic is straightforward and correct: the forward and reverse lookup maps are consistent, the previously missing conversion in ToBifrostResponsesResponse is now present, and the Anthropic path is aligned with every other path in the codebase. The one gap is that the streaming path implicitly picks up two additional mappings (stop_sequence and content_filtered) with no dedicated test, but the behavior is correct and the risk of regression is low.

core/providers/bedrock/responses.go — specifically the ToBifrostResponsesStream streaming path, which gained two additional stop reason conversions without test coverage.

Important Files Changed

Filename	Overview
core/providers/bedrock/utils.go	Adds bifrostToBedrockStopReason reverse map and convertBifrostToBedrockStopReason helper; removes guardrail_intervened from forward map; unknown reasons now pass through instead of defaulting to "stop"
core/providers/bedrock/responses.go	Fixes missing stop reason conversion in ToBifrostResponsesResponse; promotes StopReason over IncompleteDetails in ToBedrockConverseResponse; refactors streaming inline switch to use convertBedrockStopReason (adds stop_sequence→stop and content_filtered→content_filter conversions in streaming path, untested)
core/providers/anthropic/responses.go	ToBifrostResponsesResponse now uses ConvertAnthropicFinishReasonToBifrost instead of raw string passthrough — aligns with the existing streaming and chat paths
core/providers/bedrock/bedrock_test.go	Updates existing guardrail_intervened and unknown-reason test expectations; adds TestBedrockStopReasonMappingResponsesPath (non-streaming Responses path) and TestBifrostToBedrockStopReasonReverseMapping tests

_{Reviews (2): Last reviewed commit: "fix: bedrock stop reason" | Re-trigger Greptile}

The merge-base changed after approval.

[akshaydeo]

Merge activity

• May 15, 2:03 PM UTC: A user started a stack merge that includes this pull request via Graphite.
• May 15, 2:04 PM UTC: @akshaydeo merged this pull request with Graphite.