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tomo-labs

opencode

A review of the system prompts opencode sent to the model, recovered from the trace proxy: a full agent prompt and a strict title generator, stored raw and linked.

Recovered with lab prompts opencode from the trace proxy (newest capture 20260711T110419Z). Every tool routes through the proxy, which records each completion after normalizing it to the chat-completions shape, so this is the exact text that reached the model, not a copy from the tool's source. The prompts are stored raw under prompts/opencode/; this page reviews what each one does and links to the file. Sizes are in tokens, counted with the o200k_base encoding.

Agent prompt

opencode's prompt reads like a working style guide: keep replies short, prefer the search tools, follow the project's own conventions, and never invent a URL. It exposes a broad, general tool set, ten tools covering file work, search, a task tracker, and web fetch, and it spends its budget teaching the model when to reach for each rather than restating their signatures. The result is a mid-weight prompt that sits well below the heaviest agents while still driving a full toolbox.

Title generator

Beside the agent, opencode runs a small side model that names each thread. The prompt is emphatic that the model output only a title and nothing else, which is a common shape across these tools: a cheap, tool-free call whose whole job is to return one clean line.