[Bug]: pinned claude-agent-sdk 0.3.241 ships Claude Code 2.1.241, which rejects claude-fable-5-1 (needs 2.1.251+)

[orientpine]

What happened?

claude-sdk-oauth/claude-fable-5-1 is in the 2026.9.2 model catalog, but every turn on it fails. The claude-sdk-oauth provider spawns the Claude Code binary bundled with @anthropic-ai/claude-agent-sdk, and packages/coding-agent/package.json pins that SDK to exactly 0.3.241 (still 0.3.241 at HEAD, 2026.9.2-4). The SDK's own package.json says "claudeCodeVersion": "2.1.241", and the API refuses the model from that binary:

API Error: 400 Claude Code 2.1.241 does not support this model; version 2.1.251 or newer is required. Run 'claude update', or update the Claude desktop app, then try again.

Same prompt, only the binary differs (repro is against the binaries directly, so no extension is involved):

binary	version	-p --output-format json --model claude-fable-5-1 "Reply with exactly PONG"
node_modules/@anthropic-ai/claude-agent-sdk-linux-x64/claude (what senpi spawns)	2.1.241	rc=1, "is_error":true, "terminal_reason":"api_error", "api_error_status":400, modelUsage only has claude-haiku-4-5-20251001
~/.local/bin/claude (standalone install)	2.1.258	rc=0, "terminal_reason":"completed", modelUsage includes claude-fable-5-1

Workaround that works today: export CLAUDE_CODE_EXECUTABLE="$HOME/.local/bin/claude" — core/extensions/builtin/claude-sdk-oauth/executable.js checks that override first. It only takes effect for sessions launched from a shell that has it; an already-running session / RPC host keeps the bundled binary.

Steps to reproduce

1. Install @code-yeongyu/senpi@2026.9.2 (mine comes via omo-ai@5.0.0-0.beta.34, bun global). Confirm node_modules/@anthropic-ai/claude-agent-sdk/package.json has "version": "0.3.241" / "claudeCodeVersion": "2.1.241".
2. Leave CLAUDE_CODE_EXECUTABLE unset.
3. Select claude-sdk-oauth/claude-fable-5-1 in a session, or call the bundled binary directly:

   node_modules/@anthropic-ai/claude-agent-sdk-linux-x64/claude -p --output-format json --model claude-fable-5-1 "Reply with exactly PONG" < /dev/null
   

4. Get the 400 above. Point CLAUDE_CODE_EXECUTABLE at any Claude Code >= 2.1.251 and the same call succeeds.

Expected behavior

A model listed in the catalog should work with the SDK senpi ships. Bumping the pin to >= 0.3.251 fixes it with no code change — npm currently has 0.3.251, 0.3.252, 0.3.257, 0.3.258, and SDK 0.3.N tracks Claude Code 2.1.N. Nice-to-have: when this specific 400 comes back, print the "bump the SDK / set CLAUDE_CODE_EXECUTABLE" hint instead of the bare API error.

Side note, not root-caused: running a nested omo -p --mode json --model claude-sdk-oauth/claude-fable-5-1 "..." from inside a live senpi session hangs with no output (240 s, with and without the override), which is why the repro above uses the binary directly. Can file separately if that's useful.

Version

@code-yeongyu/senpi 2026.9.2 (via omo-ai 5.0.0-0.beta.34), @anthropic-ai/claude-agent-sdk 0.3.241 (bundled Claude Code 2.1.241), Linux x64 glibc, bun 1.3.14.

[thisisjun786]

Still reproducing on the released artifacts, since 7e81b13 (#1310) has not shipped yet:

• omo-ai@5.0.0-0.beta.35 (released today) bundles @code-yeongyu/senpi@2026.9.2-4 → pins @anthropic-ai/claude-agent-sdk@0.3.241
• npm view @code-yeongyu/senpi@2026.9.3 dependencies (current latest, cut 2026-09-03T00:43Z, before the bump) → still 0.3.241

What the user actually sees on omo beta.35 (~/.omo/agent/logs/fallback.log):

{"ts":"2026-09-03T03:22:17.747Z","event":"cooldown_noted","selector":"claude-sdk-oauth/claude-fable-5-1","errorMessage":"unknown"}
{"ts":"2026-09-03T03:22:17.756Z","event":"fallback_applied","from":"claude-sdk-oauth/claude-fable-5-1","to":"kimi-coding/k3","reason":"hard-error"}

i.e. the 400 version-floor text from the binary is lost and surfaces as unknown (which I assume #1312 addresses). Note the hoisting differs from the layout described above: under omo-ai beta.35 only the JS SDK is nested in senpi/node_modules/@anthropic-ai/, while claude-agent-sdk-linux-x64 is hoisted to omo-ai/node_modules/@anthropic-ai/. resolveClaudeCodeExecutable handles that fine (it resolves relative to the JS SDK), just mentioning it since the repro table refers to the sibling path.

Confirmed fix on the same machine: replacing both packages with 0.3.259 (binary reports 2.1.259 (Claude Code)) makes claude -p --model claude-fable-5-1 "Reply with exactly one word: ok" return ok with rc=0, and fable-5-1 works again in omo sessions.

Is a senpi release with 7e81b13 planned soon? omo-ai will also need to bump its bundled senpi before this reaches omo users.