codesynapse-pi

Pi coding agent extension that brings codesynapse code intelligence into pi.

Architecture

pi agent
└── codesynapse-pi extension
    (session_start · session_shutdown · /codesynapse)
         │
         │  stdin/stdout · JSON-RPC 2.0
         ▼
    codesynapse MCP (Rust binary)
         │
         ▼
    graph index  (~/.codesynapse)

Install

# From npm
pi install npm:codesynapse-pi

# From source
cd pi/
npm install
npm run build
pi -e ./dist/extension.js

Tools (12 curated)

| Tool | Purpose | |------|---------| | codesynapse_context | PRIMARY — search + call graph + source bodies (call this FIRST) | | codesynapse_resolve | BM25+dense hybrid search fallback | | codesynapse_stats | Session dashboard, token savings | | codesynapse_blast_radius | Find everything affected by a change | | codesynapse_hierarchy | Class inheritance tree | | codesynapse_list_graphs | List all available modules | | codesynapse_module_summary | Module overview (nodes, edges, god-nodes) | | codesynapse_outline | Compact class structure (methods, fields, line numbers) | | codesynapse_read_method | Get exact method body via brace tracking | | codesynapse_find_callers | Who calls a symbol | | codesynapse_find_usages | All files referencing a class | | codesynapse_build | Reload graph after module changes |

Commands

• /codesynapse — Check MCP connectivity and graph status

System Prompt

When codesynapse is detected in PATH, the extension injects guidance telling the LLM to use codesynapse_context(query) as the PRIMARY tool for architecture/mechanism questions.

Lifecycle

• session_start: Lazy-init MCP process (spawned on first tool call)
• session_shutdown: SIGTERM → 2s wait → SIGKILL the MCP subprocess

Development

# Install dependencies
npm install

# Build
npm run build

# Run unit tests (no MCP binary needed)
npx tsx --test evals/extension.test.ts

# Run integration tests (requires codesynapse in PATH)
npx tsx --test evals/mcp-integration.test.ts

# Run all tests
npx tsx --test evals/*.test.ts