fix(integrations): carry ToolMessage.error onto the tool-result flag in four more adapters - #2317
Merged
BenTaylorDev merged 1 commit intoAug 10, 2026
Conversation
…in four more adapters The same one-line omission fixed for LangGraph in ag-ui-protocol#2263 is present in several other first-party adapters: AG-UI's ToolMessage.error is not read when an incoming tool result is converted into the target framework's tool-result shape, so a client-reported tool failure is handed to the model as a success. Per the standard agreed on ag-ui-protocol#2306, set the framework's error flag from bool(error) (flag only; text is not folded because every target here has a dedicated flag): langchain/typescript ToolMessage status (verbatim ag-ui-protocol#2263); aws-strands/python Bedrock toolResult status (was pinned to success); vercel-ai-sdk/typescript AI SDK v4 tool-result isError; mastra/typescript AI SDK v4 tool-result isError. Both vercel-ai-sdk and mastra resolve AI SDK v4, whose ToolResultPart already carries isError; no version gate is needed. Also fix aws-strands _build_snapshot_messages, an AG-UI to AG-UI rebuild of the client's own messages: it dropped the client's error and encrypted_value on the snapshot echo. Copy both through. A test is added next to each adapter's conversion tests. Fixes ag-ui-protocol#2306
Contributor
Python Preview PackagesVersion
Install with uvAdd the TestPyPI index to your [[tool.uv.index]]
name = "testpypi"
url = "https://test.pypi.org/simple/"
explicit = trueThen install the packages you need: # Core SDK
uv add 'ag-ui-protocol==0.0.0.dev1785911101' --index testpypi
# Integrations (each already depends on the matching ag-ui-protocol preview)
uv add 'ag-ui-langgraph==0.0.0.dev1785911101' --index testpypi
uv add 'ag-ui-crewai==0.0.0.dev1785911101' --index testpypi
# NOTE: ag-ui-agent-spec depends on pyagentspec (git-only, not on PyPI).
# You will need to install pyagentspec separately from its git repo.
uv add 'ag-ui-agent-spec==0.0.0.dev1785911101' --index testpypi
uv add 'ag_ui_adk==0.0.0.dev1785911101' --index testpypi
uv add 'ag_ui_strands==0.0.0.dev1785911101' --index testpypiInstall with pippip install \
--index-url https://test.pypi.org/simple/ \
--extra-index-url https://pypi.org/simple/ \
ag-ui-protocol==0.0.0.dev1785911101
Commit: a31af59 |
@ag-ui/a2a-middleware
@ag-ui/a2ui-middleware
@ag-ui/event-throttle-middleware
@ag-ui/mcp-apps-middleware
@ag-ui/mcp-middleware
@ag-ui/a2a
@ag-ui/adk
@ag-ui/ag2
@ag-ui/agno
@ag-ui/aws-strands
@ag-ui/claude-agent-sdk
@ag-ui/claude-managed-agents
@ag-ui/crewai
@ag-ui/langchain
@ag-ui/langgraph
@ag-ui/llamaindex
@ag-ui/mastra
@ag-ui/pydantic-ai
@ag-ui/vercel-ai-sdk
@ag-ui/watsonx
@ag-ui/a2ui-toolkit
create-ag-ui-app
@ag-ui/client
@ag-ui/core
@ag-ui/encoder
@ag-ui/proto
commit: |
BenTaylorDev
approved these changes
Aug 10, 2026
BenTaylorDev
left a comment
BenTaylorDev
left a comment
Contributor
There was a problem hiding this comment.
Approving. CI is green across all 42 checks on 8cf5b879, and this holds up on review.
What I verified beyond reading the diff:
- Consistent with the merged #2316 and #2263. Every site derives the flag from
bool(error)/!!message.error, with no sentinel — correct, since the sentinel belongs only to the reverse direction. The five adapters now hold one rule. - The AI SDK version claims check out.
integrations/vercel-ai-sdk/typescriptresolvesai@4.3.19, whoseToolResultPartcarriesisError?: boolean. For mastra I went a level deeper, since that was the flagged uncertainty on #2306:@mastra/core@1.0.4exportsCoreMessage = AiCoreMessagefrom its bundled_types/@internal_ai-sdk-v4, and that bundledToolResultPartdoes declareisError?: boolean. - It survives
main's churn.aws-strands/.../agent.pytook 7 commits since this branch's base, including #2343's parallel tool-call rework in the same area. Merged against currentmainin a scratch worktree: no conflict, the post-merge delta is exactly this PR's 8 files, and the aws-strands suite passes at 199 — 195 baseline plus the 4 new tests, collection checked explicitly. - No interaction with the reconcile work.
session_reconcile.pynever writesstatus, so nothing downstream clobbers the flag this PR stamps. - Completeness on the sites in scope.
messages.ts:49is the only AG-UI → LangChain tool conversion; the othertoolCallIdhits across the three TS adapters are outbound streaming rather than conversion. In aws-strands,client_proxy_tool.py:58anda2ui_tool.py:640do hardcode"success", but those are placeholder and envelope results that genuinely are always successful.
One follow-up, filed as #2361 rather than held against this PR: the aws-strands fix reaches the replay_history branch only. _build_strands_history has a single caller gated on session_manager is None (agent.py:1040), so when a session_manager_provider is configured the model reads persisted toolResult blocks created by the proxy with status: "success", and _correct_message rewrites only content. A failed frontend tool is still reported as a success on that path. That's outside what #2306 scoped, and the default configuration (replay_history_into_strands=True, no session manager) takes the branch you fixed — so this is a widening job, not a defect here.
Nice work getting all four adapters onto one rule in a single pass, and for checking the AI SDK version question rather than assuming copy-paste.
This was referenced Aug 11, 2026
Merged
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
2 participants
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
Fixes #2306.
Problem
The one-line omission fixed for LangGraph in #2263 is present in several other first-party adapters: AG-UI's
ToolMessage.erroris not read when an incoming tool result is converted into the target framework's tool-result shape, so a client-reported tool failure is handed to the model as a success.Fix
Per the standard agreed on #2306: set the framework's error flag from
bool(error). Flag only — the text is not folded into content, because every target here has a dedicated flag (that carve-out only applies to transports with no flag, e.g.claude-managed-agents).langchain/typescriptmessages.tsstatus: message.error ? "error" : "success"(verbatim #2263)aws-strands/pythonagent.py_build_strands_historytoolResultstatus was pinned to"success"→ derive fromerrorvercel-ai-sdk/typescriptindex.tsisError: !!message.errormastra/typescriptutils.tsisError: !!message.errorAI SDK version
Both
vercel-ai-sdkandmastraresolve AI SDK v4, whoseToolResultPartalready carriesisError— no version gate needed.mastrabuilds the v4CoreMessagetype (theas CoreMessagecast atutils.ts:212is what currently hides the missing field fromtsc), so its behavior is pinned with a test rather than relying on a type read.Bonus: aws-strands snapshot echo
_build_snapshot_messagesis an AG-UI → AG-UI rebuild of the client's own messages (it seedsMessagesSnapshotEvent). It dropped the client's ownerrorandencrypted_valueon the echo. Both are now copied through. This one has no framework mapping and no invent-the-text question — it is a plain field copy.Scope
Flag only, one PR for all four adapters plus the snapshot fix, matching the group decision on #2306. The
docs/concepts/tools.mdxexample is being handled separately.Tests
A test is added next to each adapter's conversion tests, matching #2263's shape.
mastra: full package suite green, 304 tests (2 existing tool-result assertions updated for the always-presentisError).langchain/typescript: newmessages.test.ts, 13 tests green.vercel-ai-sdk/typescript: newmessages.test.ts, 8 tests green.aws-strands/python: newtest_tool_error_status.py,pytest tests/green — 180 passed, 2 skipped.