v0.2.0 — providers, permissions and a fullscreen UI

⚒️ Smith v0.2.0 — the release where the harness grew up: it talks to four providers, runs a fullscreen terminal UI, and asks before it changes anything.

46 commits since v0.1.0.

Providers & models

• Native Anthropic Messages API and native OpenAI API providers, alongside OpenRouter and a new Ollama provider for local models.
• Each provider defines its own default model, so -m is an override rather than a requirement.
• Streaming (SSE) for every provider — tokens appear as they are produced.
• Prompt caching for Anthropic: the system prompt and tool definitions are cached across turns.
• Thinking / reasoning blocks are requested, parsed and shown for Anthropic and OpenAI.
• Auto-continue when a response is cut off at the output-token limit, instead of handing back a truncated answer.
• HTTP timeouts on every provider call, and a Ctrl+C that saves the session before it exits.

The fullscreen terminal UI

Interactive sessions on a real terminal now render through a fullscreen interface. The transcript stays in the terminal's scrollback — copyable, searchable, no alternate screen — while the bottom of the screen carries a live region: streaming text, running tools with spinner and elapsed time, a status bar with model, mode, tokens and cost, and the input line.

• Enter submits, Esc clears the input, Up/Down walks prompt history, Ctrl+L redraws from scratch. Resizing the window redraws it too, once the drag has come to rest.
• While the agent works, Esc asks it to stop; a second press within two seconds exits.
• Approval, plan review and the hooks trust prompt are panels answered with a single key — nothing reads from plain stdin any more.
• --no-tui falls back to the line renderer. Headless smith run stays plain, so its output remains scriptable.

Deciding what the agent may do

• Approval gate for mutating tools (bash, write_file, edit_file), with an allowlist for commands you trust.
• Fine-grained permission rules — allow / ask / deny with path scoping.
• Plan mode (--plan, or /plan in chat): research first, act only after the plan is approved.
• Hooks as extension points around the agent loop (PreToolUse, PostToolUse, Stop and friends), gated behind a one-time per-project trust decision.
• Checkpoints & rewind: undo a run's file changes, one step at a time or back to the start.

Tools

• Background bash jobs — dev servers and long builds keep running, with auto-backgrounding instead of a kill.
• web_fetch and web_search, with an SSRF guard and Brave / Tavily / SearxNG adapters.
• todo_write for structured multi-step plans.
• MCP client (stage 1): stdio transport, tools/list and tools/call, so MCP servers register as ordinary smith tools.
• Custom agent definitions in .smith/agents/<name>.md, plus bounded subagent nesting depth and a shared spawn budget.

Sessions & context

• ~/.smith/config.toml with a documented precedence chain, instead of hardcoded defaults.
• Transcript compaction to stay inside the context window.
• Session ergonomics: names, -c to continue, smith context for a token breakdown, cost reporting and a spend budget, and fork.
• @-mentions embed files directly in the prompt, with budgets and a path guard.
• --json for machine-readable headless output.

Fixes worth naming

• A background job's exit notification could crash the fiber that reported it.
• An empty model response was swallowed silently instead of being shown.
• rewind undid the whole session where it should have undone one step.
• Hook stdin is written directly rather than handed to Process as an IO.
• Assistant messages with neither content nor tool calls are never sent.

Install

tar -xzf smith-v0.2.0-darwin-arm64.tar.gz
mv smith ~/.local/bin/

The attached binary is macOS arm64, ad-hoc signed — built with Crystal 1.21. On other platforms, build from source with make release.

Full changelog: v0.1.0...v0.2.0