Running Wintermolt

Running Wintermolt

Wintermolt is a single Zig binary: an agentic AI CLI (the MIT/open-source lite version of Wintermute, an OpenClaw-like assistant). Multi-backend (Ollama, Claude, OpenAI-compat, local Metal "kernel"), with tools, MCP, and skills.

Build

zig build                # → zig-out/bin/wintermolt (silent on success)

Needs system libcurl + sqlite3 (preinstalled on macOS). Zig 0.15.x (via zigup at ~/.local/share/zigup/). Cross-compile: zig build -Dtarget=aarch64-linux-gnu (Jetson/Pi) or x86_64-linux-gnu.

Run + verify (the smoke test)

Single-shot — exercises the full agent loop, exits when done:

./zig-out/bin/wintermolt -e "Reply with exactly: WINTERMOLT OK"

Expected: WINTERMOLT OK on stdout. Two benign stderr lines always appear ([config] Run 'wintermolt --setup'... and [mcp-client] No config...) — not errors.

REPL — drive it by piping commands (it reads stdin line-by-line):

printf '/stats\n/schedule list\n/quit\n' | ./zig-out/bin/wintermolt

Expected: ASCII banner, stats block (backend/model), jobs list, Goodbye.

Backend requirement

Prompts need an AI backend. Default is Ollama at localhost:11434 (check: curl -s http://localhost:11434/api/tags). No Ollama → set ANTHROPIC_API_KEY and use /model claude, or expect a backend error. Slash commands (/stats, /help...) work without any backend.

Other modes

--help (full list), --web (web UI), --gateway (OpenAI-compat server, port WINTERMOLT_GATEWAY_PORT default 8080), --mcp-server, --chat, --keys (configure API keys). Kernel backend (/model kernel) is darwin-arm64 only, loads GGUF weights via llama.cpp/Metal.

Gotchas

• Segfault in tools.getRelevantDefinitions / near-null fault address: dangling module-global pointer. AgentLoop.init returns by value, so pointers into its frame die. Globals in src/agent/tools.zig must be re-bound from self via AgentLoop.bindTools() (called in main.zig after init and at the top of processInput). If you add a new tools.setX() global, bind it there — never from a local inside init.
• Build is silent on success; zig build 2>&1 | tail shows errors only.
• The REPL prompt contains ANSI color codes — match on content, not > .

Source: lupin4/wintermolt — distributed by TomeVault.