Pi Verifier Agent

Pi package for a two-agent builder/verifier workflow. The builder runs normally in your terminal while a read-only verifier Pi instance runs in a sibling tmux window. After each builder turn, the verifier reads the bounded session slice, checks the builder's claims against repository state, and sends concrete corrective feedback back to the builder when verification fails.

Install

pi install npm:@mporenta/pi-verifier-agent

Then launch Pi with the package enabled and pass --verifiable:

pi --verifiable

For repo-local development in pi-dev:

pi -e extensions/verifier/verifiable.ts --verifiable

The package includes its own verifier persona and prompt templates under agents/ and prompts/. The default verifier model is openai-codex/gpt-5.5, which uses Pi's ChatGPT/Codex subscription auth route. Do not change this to openai/gpt-5.5 unless you intend to use the API-key OpenAI provider.

Project-local overrides are supported. If the current project has .pi/agents/verifier.md, the package uses that persona instead of agents/verifier.md. Custom persona names use the same pattern: --verifier-agent foo resolves .pi/agents/foo.md before packaged agents/foo.md. If the project has .pi/verifier/prompts/verify_on_stop.md, the verifier uses that prompt instead of the packaged prompts/verify_on_stop.md.

Package Contents

• verifiable.ts: builder-side extension that owns the socket server, spawns the verifier child, and forwards lifecycle events.
• verifier.ts: verifier-side extension loaded into the child Pi process.
• verifiable-footer.ts: builder input-bar status renderer.
• _shared/: IPC, persona parsing, tmux launch, and socket helpers.
• agents/verifier.md: default read-only verifier persona.
• prompts/verify_on_stop.md: prompt fired after each builder turn.
• prompts/builder_error.md: terse renderer template for builder error events.

Development

npm ci
npm run typecheck
npm run pack:dry-run