Myc MCP server

myc

A local, fast task-and-memory layer for coding agents: a task queue, an oplog of facts and decisions, hybrid (lexical + vector) search over the project's memory, and a built-in code index — with no network calls of its own and no mandatory LLM key. The network is reached only when you ask: myc models fetch, myc code fetch, myc version --check (or MYCUPDATECHECK=1, a background version check at most once a day from init and wire).

Agents forget. myc is the part that doesn't: decisions survive context compaction, work survives process death, and both survive being moved between machines through plain git.

Design docs live in docs/design/ (start with 00-brief.md); the measurements quoted below are reproducible from bench/ and scripts/.

Site: — every capability with the release it arrived in and a command that shows it, the roadmap, and the measurements as charts, in English and Russian, with the command that reproduces each number printed next to it. It is the one source of numbers: bun run site/build.ts checks every figure on the site against the measurement artefacts in this repository, the figures in this README and in the Russian one against the site's site/measurements.json, and every myc command and flag on the site and in both READMEs against this build's --help; a mismatch fails the build.

Requires Bun — this is not fine print

The runtime is bound to bun:sqlite (no native bindings on the Node side). It will not start on plain Node.js or Deno. Bun ≥ 1.3.0 is required and pinned in package.json → engines.bun.

SQLite ≥ 3.44.0. Below 3.44.0, FTS5 cannot be written from triggers under trustedschema = OFF, so every write fails. On Linux, Bun links its own SQLite (3.53.0 in Bun 1.3.14). On macOS, Bun uses the system SQLite — 3.43.2 on macOS 14 — so the package ships its own: vendor/sqlite/libmyc-sqlite3.dylib, SQLite 3.53.4 built from the official amalgamation for arm64 and x8664 (scripts/build-sqlite.ts), chosen before anything else except an explicit MYCSQLITE=/path/to/libsqlite3.dylib. If the SQLite in use is still below 3.44.0 — a broken install, or MYCSQLITE pointing at an old library — every command, myc init included, refuses with precond.sqliteunsupported and says what to do, instead of creating a workspace it cannot write to. From 3.44.0 up to 3.51.2 myc works but warns (WARN degraded.sqliteold): parallel processes may run a background job more than once; on Linux the cure is bun upgrade. myc doctor names the SQLite in use and where it came from.

Install Bun: https://bun.sh

Install

Installation is one command:

bun install -g @aistastudio/myc   # 5.06 MB compressed, 15.63 MB unpacked, 16 files; no models pulled
myc --version                     # myc 0.3.14 (schema 1)

It runs on macOS and Linux. On Windows, use WSL and install Bun and myc inside it: the myc launcher does not start in cmd or PowerShell, and an npm install on Windows says so.

The embedding model is not downloaded during install. Semantic search is opt-in and explicit: myc models fetch (129 MB, ~7 s). Until then search is lexical and says so on every answer (WARN degraded.embeddings). The grammars for the code index are fetched the same way, once: myc code fetch.

To run the newest code instead of the published release, build from source:

git clone https://github.com/aistastudio/myc && cd myc
bun install
bun run build          # produces a single binary: dist/myc
./dist/myc --version

Put the binary somewhere myc wire can find it — MYCBIN, nodemodules/.bin, ~/.myc/bin/myc, or PATH. If it can't, wire says so out loud instead of writing a config that silently won't start.

Quick start

Two commands set a project up; the rest is the loop an agent lives in. (From a source build, ./dist/myc instead of myc.)

Shortened. The full README is on GitHub.