Anthropic's newly released Claude Opus 5.5 model strictly requires
claude-cli version 2.1.280 or newer. Spoofing the older 2.1.258
version results in an HTTP 400 `claude_code_version_too_old` error.
This commit updates the hardcoded `CLAUDE_CLI_VERSION` in
`open-sse/providers/shared.js` and aligns the corresponding unit
tests and baselines to bypass Anthropic's version gating.
- add claude-fable-5-1 to the Claude Code model catalog (1M context,
permanent adaptive thinking)
- centralize the spoofed Claude Code version and update both request
and billing identities to 2.1.257 (Fable 5.1 rejects < 2.1.251)
- send output_config.effort without the redundant thinking switch for
permanently adaptive models
- add regression coverage for capabilities, headers, billing identity
and adaptive-effort payload
# Conflicts:
# open-sse/providers/registry/claude.js
# open-sse/providers/shared.js
# open-sse/utils/claudeCloaking.js
# tests/__baseline__/providers-baseline.json
translateResponse() short-circuited untouched on claude->claude streaming,
so OAuth-cloaked tool names (CLAUDE_TOOL_SUFFIX) leaked to the client and
every tool call was rejected as unknown. Add decloakStreamChunk(), the
streaming counterpart of decloakToolNames(), and call it on the same-format
path using the already-plumbed state.toolNameMap.
convertOpenAIToolChoice mapped {type:"function"} verbatim and cloakClaudeTools
left tool_choice.name unsuffixed, both rejected by Claude on the cc/ path.
Map forced-function to {type:"tool",name}, allowlist Claude-valid types, and
suffix tool_choice.name when it targets a renamed client tool.
Fixes#1592
Co-authored-by: Cursor <cursoragent@cursor.com>
