archon-pi

A pi coding agent extension that gives pi a web_search tool powered by a local SearXNG instance. Queries are rewritten into tighter search terms via Ollama before hitting SearXNG.

How it works

1. Pi calls web_search with a natural-language query
2. The query is sent to Ollama's /api/generate to be condensed into a short, precise search string (max 8 words)
3. The rewritten query hits SearXNG's JSON API
4. The top N results are returned to pi as formatted Markdown

The extension also hooks session_start, tool_execution_start, and tool_execution_end to show live status in the pi UI.

Prerequisites

• Ollama running locally
• Docker (for SearXNG)
• pi coding agent installed (npm i -g @mariozechner/pi-coding-agent; provides the pi CLI)

Setup

1. Start Ollama

ollama serve
ollama pull qwen3-coder-next:latest
ollama pull mistral:7b

2. Start SearXNG

docker compose up -d

SearXNG will be available at http://localhost:8080.

3. Install the extension

# Global — available in all pi sessions
mkdir -p ~/.pi/agent/extensions
cp .pi/extensions/archon-search.ts ~/.pi/agent/extensions/archon-search.ts

# Project-local — only active when pi runs in this directory
# (already present if you cloned this repo)

Pi auto-discovers extensions from ~/.pi/agent/extensions/ and from .pi/extensions/ in the current working directory.

4. Run pi

pi --model ollama/qwen3-coder-next:latest

The web_search tool is registered automatically on session start.

Configuration

Copy .env.example to .env and adjust as needed. All variables are optional — the defaults work out of the box. Pi does not load .env files automatically, so either export the variables in your shell, or start pi with something like set -a && source .env && set +a && pi (bash).

Variable	Default	Description
ARCHON_OLLAMA_HOST	http://localhost:11434	Ollama API base URL
ARCHON_MODEL	mistral:7b	Model used for query rewriting
ARCHON_SEARXNG_URL	http://localhost:8080	SearXNG instance URL
ARCHON_SEARCH_TOP_N	5	Number of results to inject
ARCHON_SEARCH_CATEGORIES	general,it	SearXNG search categories
ARCHON_REWRITE_QUERY	true	Use Ollama to rewrite queries before searching

Project structure

.
├── .pi/
│   └── extensions/
│       └── archon-search.ts   # The pi extension
├── searxng/                   # SearXNG Docker configuration
├── docker-compose.yml         # Spins up a local SearXNG instance
├── .env.example               # Environment variable reference
└── README.md