What is pi-extension-authoring?

A guide for building Pi extensions in TypeScript, where Pi is a coding-agent framework. It explains how to add tools, commands, interface elements, resources, and custom model connections.

Use it when creating Pi tools or commands, responding to agent events, adding interface components, loading extra skills, or connecting custom providers.

It provides the project-specific instructions needed to extend or debug Pi without relying on guesswork.

pi-extension-authoring — Skill for Claude Code by romiluz13

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.

Any agent

npx skills add romiluz13/pi-agent-skills --skill pi-extension-authoring

Clone the repo

git clone --depth 1 https://github.com/romiluz13/pi-agent-skills

Made for: Claude Code.

Or install pi-skill, the plugin that ships this one along with the rest of its 11 skills.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

README.md

[![agentmods](https://agentmods.dev/badge/skills/romiluz13/pi-agent-skills/pi-extension-authoring/github.svg)](https://agentmods.dev/skills/romiluz13/pi-agent-skills/pi-extension-authoring)

Your own site

<a href="https://agentmods.dev/skills/romiluz13/pi-agent-skills/pi-extension-authoring"><img src="https://agentmods.dev/badge/skills/romiluz13/pi-agent-skills/pi-extension-authoring/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

Your own site · 80×15

<a href="https://agentmods.dev/skills/romiluz13/pi-agent-skills/pi-extension-authoring"><img src="https://agentmods.dev/badge/skills/romiluz13/pi-agent-skills/pi-extension-authoring.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 104 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 620 The whole file, excluding the scripts and references it only reads on demand.

Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.

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.

Model	Per session	Once invoked
Fable 5.1	$0.00104	$0.00620
Opus 5.5	$0.00042	$0.00248
Sonnet 5.5	$0.00021	$0.00124
Haiku 4.5	$0.00010	$0.00062

Measured 2mo ago against content hash f190a4570dad, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

pi-extension-authoring 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 2mo 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.

pi-skills/pi-extension-authoring/SKILL.md · 35 lines

How it starts

The opening of the file, as written. The whole thing — 35 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Pi extension authoring

Ground every answer in pi-mono/ files below.

Grounding

pi-mono/packages/coding-agent/docs/extensions.md — capabilities, lifecycle, patterns.
pi-mono/packages/coding-agent/examples/extensions/README.md — runnable examples index.
pi-mono/packages/coding-agent/src/core/resource-loader.ts — extendResources() appends paths via mergePaths after existing lastSkillPaths (late paths lose name collisions to earlier ones unless names differ).
pi-mono/packages/coding-agent/src/core/agent-session.ts — extension commands vs queued prompts; skill expansion hooks.
pi-mono/packages/coding-agent/docs/tui.md — extension TUI component integration with @mariozechner/pi-tui: Component rendering contract, overlay patterns, input handling in extension context.
pi-mono/packages/coding-agent/docs/custom-provider.md — registerProvider() for proxies, OAuth/SSO, custom APIs, and custom model definitions.

Invariants

Extensions can register tools, commands, themes, prompts, and extra skill paths; exact API surface is defined in docs and example modules — start from docs/extensions.md, not memory.
Dynamic resource discovery patterns live under pi-mono/packages/coding-agent/examples/extensions/ (e.g. dynamic-resources/ listing in examples README).

Workflows

New extension: Read docs/extensions.md, clone the closest examples/extensions/ template, then align with project AGENTS.md if working inside pi-mono.
Skills from extensions: Trace extendResources + mergePaths in resource-loader.ts to explain ordering with user/project/package skills.
Extension TUI: Read docs/tui.md for the Component rendering contract in extension context; combine with pi-tui skill for library-level APIs.
Custom providers via extension: See pi-mono/packages/coding-agent/docs/custom-provider.md for registerProvider() OAuth flows and proxy patterns (grounded in pi-cli-workspace).

Anti-patterns

Read the full file on GitHub · 35 lines

Files

What ships with it

1 file beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

references/CORPUS.md 335 B

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.

2mo ago First seen · 35 lines · 104 tokens per session scan A f190a4570dad

Subscribe to this mod's changes

pi-extension-authoring is a skill published in the GitHub repository romiluz13/pi-agent-skills (20 stars, last pushed 7mo ago), licensed MIT. It adds 104 tokens to every session and 620 once invoked, about $0.0004 per session on Opus 5.5. 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 2026-08-30.

Building agents Languages TypeScript

pi-extension-authoring next to 6 skills from other repositories
Mod	Type	Stars	Last push	Licence	Scan	Tokens	Works with
pi-extension-authoringromiluz13/pi-agent-skills	Skill	20	7mo ago	MIT	A	104	Claude Code
no-bare-castsprisma/orm	Skill	48k	today	Apache-2.0	A	52	Claude Code, Codex
aws-sst-developmentsickn33/agentic-awesome-skills	Skill	49k	today	MIT	A	26	Claude Code
league-akari-shard-developmentLeagueAkari/LeagueAkari	Skill	4.7k	yesterday	MIT	A	58	Claude Code, Codex
dd-code-generationDataDog/pup	Skill	1.0k	today	Apache-2.0	A	16	Claude Code
fast-typescript-checkinternet-development/www-sacred	Skill	1.6k	5d ago	MIT	A	84	Claude Code, Codex
typescript-magicianmcollina/skills	Skill	2.0k	13d ago	MIT	A	108	Claude Code, Codex