pi-fastcontext

Pi extension that exposes a fast_context_search tool backed by a local Microsoft FastContext llama.cpp server. Returns compact file:line citations for read-only codebase search.

How it works

1. Spawns a mini agentic loop against a locally running llama.cpp server.
2. The FastContext model gets three tools: GLOB, GREP, READ (all scoped to the repo root).
3. Runs up to maxTurns tool turns, then forces a <final_answer> block.
4. Citations are validated (file exists, line numbers in bounds) and normalised to repo-relative paths.
5. Returns up to 12 relative/path:START-END — short reason lines.

Prerequisites

Requirement	Details
llama.cpp server	Running at http://127.0.0.1:8772/v1 (default) with a FastContext model loaded
Model file	Default: FastContext-1.0-4B-RL-Q4_K_M.gguf

Tool parameters

Parameter	Type	Description
query	string	Natural-language code search query
cwd	string?	Repository root. Defaults to current pi cwd
baseUrl	string?	OpenAI-compatible base URL. Defaults to config or http://127.0.0.1:8772/v1
model	string?	Model ID. Defaults to config or FastContext-1.0-4B-RL-Q4_K_M.gguf
maxTurns	integer?	Tool turns before forced finalization (1–8). Default 6
maxTokens	integer?	Max tokens per model response (128–4096). Default 1400
includeTranscript	boolean?	Include raw turn-by-turn transcript in tool details. Default false

Commands

/fastcontext <query>    — run a code search and display results as a notification

Configuration

Global config: ~/.pi/agent/fastcontext.json

Config resolved in priority order: built-in defaults → user config → project config (.pi/fastcontext.json) → env vars → tool call parameters.

Option	Type	Default	Description
baseUrl	string	http://127.0.0.1:8772/v1	OpenAI-compatible base URL for the FastContext server
model	string	FastContext-1.0-4B-RL-Q4_K_M.gguf	FastContext model ID
maxTurns	integer	6	Maximum tool-call turns per search (1–8)
maxTokens	integer	1400	Max tokens per model response (128–4096)

{
  "$schema": "./.pi/agent/fastcontext/config.schema.json",
  "baseUrl": "http://127.0.0.1:8772/v1",
  "model": "FastContext-1.0-4B-RL-Q4_K_M.gguf",
  "maxTurns": 6,
  "maxTokens": 1400
}

Environment variables

Variable	Description
FASTCONTEXT_BASE_URL	Override llama.cpp server URL
FASTCONTEXT_MODEL	Override model ID
FASTCONTEXT_MAX_TURNS	Override max tool turns
FASTCONTEXT_MAX_TOKENS	Override max tokens per response