Pi
A minimal harness with package resources, skills, extensions, prompts, and target settings
- harness
- pi
- setup
Pi is a minimal local coding agent. Its strength is a transparent resources layer: skills and prompt templates come from directories or packages, while settings explicitly decide which extensions and models are available. That keeps a setup small and inspectable, but it also means Pi must not be assigned capabilities belonging to another harness.
Native surface
| Area | What Pi reads | ai-stp projection |
|---|---|---|
| User | ~/.pi/agent/AGENTS.md, skills/, extensions/, prompts/, settings.json, models.json | Global instruction, skill, plugin, command, and setting |
| Project | .pi/skills/, .pi/extensions/, .pi/prompts/, .pi/settings.json | Project resources after project trust |
| Package | npm/git package with resources | Portable skills and extensions |
| MCP | No separately documented native MCP configuration | Integration belongs in an extension/package, not an invented MCP file |
Pi uses AGENTS.md as instruction, while a project override can change loading order. Project resources also depend on the trust decision: the presence of .pi/settings.json does not mean Pi will automatically permit its contents.
How the setup is assembled
ai-stpseparates authored resources fromauth.json, model store, cache, and session state.- The passport records the exact package or local source, scope, and role of each component.
- The assembler checks that skills, prompts, extensions, and settings land on supported Pi surfaces.
- The public
pi-setup-systemreceives the exact plan and writes only the target Pi directory. The website does not start Pi or change its active session.
In catalog terms, Pi uses skill for on-demand workflow, plugin for extension/package, command for prompt template, setting for the JSON profile, and no separate native MCP kind.
When to choose Pi
Pi fits a compact local setup where package resources, skills, and manual settings control matter. For a team, keep .pi/ beside the project and check trust before enabling extensions.
Links
Trust boundary
Pi is a local agent without a built-in sandbox, so read skills, packages, and extensions before enabling them. The ai-stp support tier does not replace content review, version pinning, or rollback.
Observe → passport → project trust → resource check → exact plan → provider installation.