What it does

cursor2api sits between your AI client and Cursor’s undocumented /api/chat endpoint, translating Anthropic Messages API and OpenAI Chat Completions requests into whatever Cursor’s docs page expects back. It ships with a web log viewer, token auth, and a small army of workarounds for truncation, refusals, and identity leaks.

The interesting bit

The README opens with “20260401 Cursor文档页仅剩gemini-3-flash （凉）” — roughly, “as of April 2026, Cursor docs only has Gemini 3 Flash, it’s dead.” The project is essentially a sophisticated workaround for a free tier that may already be a corpse. That context-pressure-inflation trick — lying about input_tokens so Claude Code compresses history earlier — is the kind of ugly-hack-turned-feature that keeps agentic coding sessions alive when the backend silently caps output.

Key highlights

• Dual protocol front: Anthropic /v1/messages and OpenAI /v1/chat/completions, plus a /v1/responses shim for Cursor IDE Agent mode
• Truncation recovery: semantic detection + auto-continuation for long Write/Edit tool calls, with configurable auto-retry limits
• Context compression: three aggression levels, schema squashing (~135k → ~15k chars), and adaptive token budgets that reserve more headroom as tool count grows
• Identity laundering: 50+ refusal patterns, probe interception, and optional response sanitization to keep the model answering as “Claude”
• Vision fallback: local CPU OCR or external vision API proxy when the upstream doesn’t handle images
• Full-chain logging UI with SSE streaming, dark mode, and SQLite/JSONL persistence

Caveats

• The upstream free API appears to have degraded to Gemini 3 Flash as of the README’s April 2026 note; project viability is unclear
• Cursor IDE integration requires Cursor Pro membership and a public HTTPS domain; localhost won’t cut it
• Most anti-truncation features (context pressure inflation, adaptive budgets, smart tool-result truncation) are disabled by default and must be explicitly enabled

Verdict Worth a look if you’re already running Claude Code daily and want to squeeze mileage out of Cursor’s web tier — assuming that tier still breathes. Skip it if you have a real Anthropic API key and value stability over free-tier archaeology.