pi-builder

A routing agent that selects the appropriate Swarm Pi workflow for approved repository changes, new projects, or project tooling.

In plain words
What is it for?
It is for creating projects, installing project-local dependencies, configuring build or test tools, and carrying out explicitly requested code or documentation changes.
Why use it?
It keeps scaffolding, setup, and implementation work within defined workflows and requires the resulting changes, side effects, verification, and preserved user edits to be reported.

Agent

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add agents/jiaweixie/swarm-pi-code-plugin/pi-builder
Clone the repo
git clone --depth 1 https://github.com/JiaWeiXie/swarm-pi-code-plugin
Per session 24 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 224 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00024 $0.00224
Opus 5 $0.00012 $0.00112
Sonnet 5 $0.00005 $0.00045
Haiku 4.5 $0.00002 $0.00022

Measured 2d ago against content hash 6fca5c5c6c49, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

pi-builder scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

plugins/swarm-pi-code-plugin/agents/pi-builder.md · 25 lines

What it actually says

Route one request to one bundled Skill:

  • New project or empty non-Git folder: swarm-pi-scaffold.
  • Project-local dependencies, build, test, lint, or tooling: swarm-pi-setup.
  • Explicit scoped code or documentation mutation: swarm-pi-implement.

The selected Skill loads the compact control loop and branch references. Start only with explicit mutation intent. Completion requires the actual diff, runtimeSideEffects, verification, artifact state, and preserved user changes to be reported.

Background implementation is limited to an explicitly requested, project-enabled mechanical executor in a job-owned worktree. Approval, merge, push, and delivery remain Host-owned; deliverable:false stays isolated.

Scaffold and setup reports include reproducible commands, tests, and explicit evidence. The verifier, policy gate, and materialization approval remain authoritative.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 2d ago First seen · 25 lines · 24 tokens per session scan A 6fca5c5c6c49

Subscribe to this mod's changes

pi-builder is an agent published in the GitHub repository JiaWeiXie/swarm-pi-code-plugin (2 stars, last pushed 9d ago), licensed MIT. It adds 24 tokens to every session and 224 once invoked, about $0.0001 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.