newt-core

Newt-Agent core types, errors, and the NeMoCode-style tier router.

The router is the NeMoCode inheritance: it classifies an incoming turn into a Tier (FAST / STANDARD / COMPLEX / REVIEW) and asks the configured backends which can serve that tier. The crate also carries the shared configuration model (~/.newt/config.toml), session and memory types, MCP server resolution, metrics, and capability caveat extensions used across the workspace.

It also hosts the shared agentic tool executor used by the TUI and headless paths. Built-in file tools include read_file, write_file, edit_file, delete_file, list_dir, and find, all mediated by the same caveat and prompted-permission checks.

Interactive front ends may inject the public LiveToolOutput interface into ChatCtx to observe streaming shell bytes without changing the authoritative tool result. Newt dispatches those bytes through a bounded presentation queue, contains observer panics, and runs renderer startup off the tool-execution task. Normal completion and responsive cancellation close the generation before the canonical completed result is rendered. A bounded teardown timeout instead calls the sink's no-output abandon transition synchronously, invalidating delayed callbacks before canonical rendering resumes. Headless callers set live_tool_output to None, preserving completion-only output. Each tool invocation gets a new generation, so late bytes from an ended or retried invocation are ignored. The front end owns display sanitization and retained-history policy; neither can mutate the model-facing result.

Part of Newt-Agent, a free, friendly, local agentic coder.

License

Apache-2.0