fix: Parallel tool results are serialized in completion order, silently breaking provider prompt caching

[lgrammel]

Background

Parallel tool results could be serialized in nondeterministic completion order instead of assistant tool-call order, causing equivalent histories to produce byte-different prompts and miss provider prompt caches.

Summary

Updated toResponseMessages to record assistant tool-call order and stably sort emitted tool-result content by matching toolCallId, with unknown ids kept last.

Testing

Kept the focused regression test for parallel tool calls resolving out of order and made its assertion type-safe.

Related Issues

Fixes #16567

[github-actions]

🚀 Published in:

Package	Version
ai	7.0.12 github npm
@ai-sdk/alibaba	2.0.5 github npm
@ai-sdk/amazon-bedrock	5.0.9 github npm
@ai-sdk/angular	3.0.12 github npm
@ai-sdk/anthropic	4.0.6 github npm
@ai-sdk/assemblyai	3.0.4 github npm
@ai-sdk/azure	4.0.6 github npm
@ai-sdk/baseten	2.0.4 github npm
@ai-sdk/black-forest-labs	2.0.4 github npm
@ai-sdk/bytedance	2.0.5 github npm
@ai-sdk/cerebras	3.0.4 github npm
@ai-sdk/cohere	4.0.4 github npm
@ai-sdk/deepgram	3.0.4 github npm
@ai-sdk/deepinfra	3.0.4 github npm
@ai-sdk/deepseek	3.0.4 github npm
@ai-sdk/elevenlabs	3.0.5 github npm
@ai-sdk/fal	3.0.5 github npm
@ai-sdk/fireworks	3.0.5 github npm
@ai-sdk/gateway	4.0.9 github npm
@ai-sdk/gladia	3.0.4 github npm
@ai-sdk/google	4.0.7 github npm
@ai-sdk/google-vertex	5.0.9 github npm
@ai-sdk/groq	4.0.4 github npm
@ai-sdk/harness	1.0.15 github npm
@ai-sdk/harness-claude-code	1.0.15 github npm
@ai-sdk/harness-codex	1.0.16 github npm
@ai-sdk/harness-deepagents	1.0.14 github npm
@ai-sdk/harness-opencode	1.0.15 github npm
@ai-sdk/harness-pi	1.0.15 github npm
@ai-sdk/huggingface	2.0.4 github npm
@ai-sdk/hume	3.0.4 github npm
@ai-sdk/klingai	4.0.5 github npm
@ai-sdk/langchain	3.0.12 github npm
@ai-sdk/llamaindex	3.0.12 github npm
@ai-sdk/lmnt	3.0.4 github npm
@ai-sdk/luma	3.0.5 github npm
@ai-sdk/mcp	2.0.6 github npm
@ai-sdk/mistral	4.0.4 github npm
@ai-sdk/moonshotai	3.0.6 github npm
@ai-sdk/open-responses	2.0.4 github npm
@ai-sdk/openai	4.0.6 github npm
@ai-sdk/openai-compatible	3.0.4 github npm
@ai-sdk/otel	1.0.12 github npm
@ai-sdk/perplexity	4.0.5 github npm
@ai-sdk/policy-opa	1.0.12 github npm
@ai-sdk/prodia	2.0.5 github npm
@ai-sdk/provider-utils	5.0.4 github npm
@ai-sdk/quiverai	2.0.4 github npm
@ai-sdk/react	4.0.13 github npm
@ai-sdk/replicate	3.0.5 github npm
@ai-sdk/revai	3.0.4 github npm
@ai-sdk/rsc	3.0.12 github npm
@ai-sdk/sandbox-just-bash	1.0.15 github npm
@ai-sdk/sandbox-vercel	1.0.15 github npm
@ai-sdk/svelte	5.0.12 github npm
@ai-sdk/togetherai	3.0.5 github npm
@ai-sdk/tui	1.0.12 github npm
@ai-sdk/valibot	3.0.4 github npm
@ai-sdk/vercel	3.0.4 github npm
@ai-sdk/voyage	2.0.4 github npm
@ai-sdk/vue	4.0.12 github npm
@ai-sdk/workflow	1.0.12 github npm
@ai-sdk/workflow-harness	1.0.15 github npm
@ai-sdk/xai	4.0.5 github npm