Show HN: A minimal Pareto-optimal OpenRouter model router for pi, based on Jev

A developer released pi-jev-router, a minimal Pareto-optimal OpenRouter model router for the pi coding agent that classifies tasks with a single Jev call and assigns models per role: anthropic/claude-sonnet-5 for planning, openrouter/pareto-code for code, and openai/gpt-5.4-mini for writing. The project reports writing tasks 89% cheaper and code tasks 88% cheaper under the empirical_cost profile, with planning scoring 100% pass on claude-sonnet-5. Workers dispatched via dispatch_task run in isolated Git worktrees on task/<id> branches and merge only when verifierCommand exits 0.

Jev-classified model routing for pi. | Role | Model | Thinking | |---|---|---| | Planning | anthropic/claude-sonnet-5 | high | | Code | openrouter/pareto-code | medium | | Writing | openai/gpt-5.4-mini | low | Writing tasks get STE and Humanizer rules. Code tasks run unit tests. Planning tasks get a structure check. /router show status /router shadow recommend only default /router auto switch models per task /router off stop routing /router profile pareto code | empirical cost /router budget <usd node --experimental-strip-types eval/index.ts Results: writing 89% cheaper. Code 88% cheaper with empirical cost . Planning 100% pass on claude-sonnet-5 . npm install Set OPENROUTER API KEY , or reuse the key stored in ~/.pi/agent/auth.json . Copy config/models.openrouter.json into ~/.pi/agent/models.json . Auto-load globally: mkdir -p ~/.pi/agent/extensions ln -sf ~/Documents/GitHub/pi-jev-router ~/.pi/agent/extensions/pi-jev-router Then start pi normally no -e required . Workers dispatched via dispatch task execute in isolated Git worktrees: - Worker edits code on a separate task branch task/<id . - If verifierCommand passes exit 0 , changes merge cleanly into the repository. - If verification fails or aborts, the worktree is cleaned up without leaving dirty changes. - src/classifier.ts — Jev call. One request, five questions. - src/selector.ts — policy. No model calls. - src/board.ts — SQLite task state. - src/dispatch.ts — worker spawn and handshake. - extensions/router.ts — pi hooks and commands. - eval/ — benchmark tasks, verifiers, runner.