# cellc-mcp

MCP server wrapping the `cellc` CellScript compiler so a local agentic model can
write CKB Cell contracts in a write → check → explain → inspect loop.

## Install
    python -m venv .venv && . .venv/bin/activate
    pip install -e .

## Requirements
- A built `cellc` binary. Build it once:
      cd ~/CellScript && cargo install --path .
  (Needs a sibling `ckb-sdk-rust` checkout at tag v5.1.0 per CellScript AGENTS.md.)

## Configuration (env)
- `CELLC_BIN` — path to the cellc binary (else found on PATH)
- `CELLSCRIPT_REPO` — CellScript checkout for examples/reference (default ~/CellScript)
- `CELLC_TIMEOUT` — per-call timeout seconds (default 30)

## MCP client config
    {
      "mcpServers": {
        "cellc": {
          "command": "cellc-mcp",
          "env": { "CELLSCRIPT_REPO": "/home/phill/CellScript" }
        }
      }
    }

## Tools
- `cellc_check` — type-check; terse diagnostics (max 5; `full=true` for all)
- `cellc_explain` — explain an error code (E####)
- `cellc_metadata` — compiler metadata summary (`full=true` for schema-30 JSON)
- `cellc_constraints` — verifier obligations + runtime-error registry
- `cellc_language_reference` — the full language surface, in-context
- `cellc_list_examples` / `cellc_get_example` — example contracts for grounding

## Tests
    python -m pytest -v                 # offline unit tests
    python -m pytest -m needs_cellc -v  # integration (needs cellc)