MeTTa LSPA language server for MeTTa

Hovers, diagnostics, formatting, run and trace commands, visualisation, generated reference pages, and an MCP tool for agents. The same language server core runs in VS Code, Neovim, Helix, Emacs, Sublime, browser hosts, and CLI workflows.

Open browser IDE

The language server

Diagnostics

GitHub

MeTTaGrapher playing a generate-and-test search, where candidate selections fan out, are tested, and prune to the answers

Browser IDE

Edit a persistent multi-file workspace with live diagnostics, completion, hover, navigation, rename, formatting, symbols, and guarded MeTTa evaluation. The language server runs in a Web Worker.

Rust-analyzer-style hovers

Signature, interpreter-exact type, definition site, and a link to the builtins reference. Diagnostics link to a catalogue page with the message and the fix.

Run and visualise

Run a file unguarded from the ▶ button; visualise its reduction with the interactive MeTTaGrapher, step through it, and export a GIF.

Python interop

py-atom, py-call, and py-eval evaluate against real CPython on an unguarded run. Guarded evaluation never loads the bridge, so py atoms stay inert there by construction.

Programmatic API

import { lint, diagnostics, format, run } from "metta-ts-lsp/dsl". Call language-server features from tests, scripts, agents, and browser tools.

An agent tool

The MCP server gives coding agents MeTTa intelligence: definition, references, hover, symbols, and call hierarchy. One command registers it with Claude Code, Codex, or any MCP client.

Every editor

Reads configuration from initializationOptions, a workspace/configuration pull, or a didChangeConfiguration push, so browser hosts, VS Code, Neovim, Helix, Emacs, and Sublime all work.