A coding agent that refuses to lie to you about truncation

What it does

UNCUT is a minimal coding-agent harness for pipelines, CI, containers, and experiments. It talks to any OpenAI-compatible Chat Completions endpoint (including local Ollama), gives the model four tools — read_file, write_file, replace, run_command — and prints the final answer to stdout. Optional --json emits structured NDJSON events, and --session gives you append-only JSONL sessions you can resume exactly.

The interesting bit

The whole pitch is what it refuses to do: no context compaction, no summarization, no silent output caps. The full conversation goes to the model on every call, and if the provider cuts a response at its output limit, UNCUT exits with a distinct error code (3) instead of presenting a partial answer as success. There’s a proof script in bench/ that drives the real binary against a deterministic local provider to verify the contract — transport tests, not vibes.

Key highlights

• One statically linked ~7 MB Go binary, no runtime or third-party Go dependencies; Linux/macOS/Windows, amd64 and arm64
• 837 lines of implementation Go, four tools, one provider protocol, one agent loop — genuinely forkable
• Resumable sessions: invalid or partial records cause explicit errors, never silent discards
• Rejects invalid UTF-8 and binary files outright rather than guessing or mangling bytes
• No telemetry, no TUI, no plugin system, no hidden retries or recovery loops

Caveats

• Not a sandbox: run_command runs with your OS user’s permissions, and workspace checks don’t constrain shell access — use a container for untrusted tasks
• Non-streaming only, text and tool calls only (no images); long contexts will hit provider limits hard, by design
• Binaries aren’t code-signed, so Gatekeeper/SmartScreen will complain; the README tells you to verify checksums

Verdict

Worth a look if you wire agents into CI or pipelines and want failures to be loud and honest. Skip it if you want a TUI, hand-holding, or a model that quietly survives tiny context windows.