fix(cli): identify Kilo in LLM user agent

[markijbema]

What

Fix provider request User-Agent headers emitted by the CLI LLM streaming path so they identify Kilo instead of OpenCode.

The LLM request code now uses the existing Kilo installation USER_AGENT value instead of hardcoding opencode/${InstallationVersion}. This covers both the Kilo-provider branch and the general provider branch before the AI SDK appends its own suffixes.

Why

We observed provider/request logging with a header like:

opencode/7.3.46 ai-sdk/provider-utils/4.0.23 runtime/bun/1.3.14

The ai-sdk/provider-utils/... runtime/bun/... suffix is appended by the AI SDK via its withUserAgentSuffix helper. The incorrect opencode/<version> prefix came from our code in packages/opencode/src/session/llm.ts, where two branches passed:

"User-Agent": `opencode/${InstallationVersion}`

There is already a Kilo-specific installation helper in packages/opencode/src/installation/index.ts that returns the canonical Kilo user-agent value. The bug was that the LLM path bypassed that helper.

Regression Analysis

This does not appear to be a new 7.3.46 regression. Git history shows the hardcoded LLM header was introduced by:

fc6d4b4010 core: Add User-Agent header to identify client version in HTTP requests

That commit dates to Apr 25, 2026, and is contained by many later tags. The later Kilo compatibility refactor:

6ecaaab48a refactor: kilo compat for v1.14.51

updated the installation helper to return Kilo branding, but did not update this session/llm.ts call site. So the bad prefix survived specifically on paths where DEFAULT_HEADERS does not overwrite it, such as Anthropic and Kilo-provider requests.

Testing

• bun test ./test/session/llm.test.ts from packages/opencode/
• bun run script/check-opencode-annotations.ts from repo root

[kilo-code-bot]

Code Review Summary

Status: No Issues Found | Recommendation: Merge

Files Reviewed (3 files)

• .changeset/fix-llm-user-agent.md
• packages/opencode/src/session/llm.ts
• packages/opencode/test/session/llm.test.ts

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_{Reviewed by deepseek-v4-pro-20260423 · 263,855 tokens}

_{Review guidance: REVIEW.md from base branch main}