grex

A nested meta-repo manager. Track many git repos as a single graph, sync them in parallel, and drive every operation from a shell, CI, or an LLM agent speaking MCP.

grex is what you reach for when one git repo is no longer enough — when you have a tree of related repos (a workspace, a fleet of services, a set of dotfiles + plugins + tools) and you want one declarative source of truth that says which repos belong, where they live on disk, and how they're kept in sync.

It is not a dev-environment installer, not a package manager, not mise / asdf. It manages repos, not language toolchains.

In 30 seconds

cargo install grex-cli                       # binary is `grex`
grex init                                    # creates grex.jsonl in cwd
grex add https://github.com/you/svc-a        # registers + clones a sub-repo
grex add https://github.com/you/svc-b
grex sync                                    # parallel pull/clone for all
grex status --json                           # machine-readable state

grex.jsonl (intent) and grex.lock.jsonl (resolved state) are the only files you commit to your meta-repo. Everything else grex does — clone, pull, run actions, talk MCP — is reproducible from those two files.

What you get

• One CLI, twelve frozen verbs. init add rm ls status sync update doctor serve import run exec. Universal --json --plain --dry-run --parallel <N> --filter <EXPR> on every verb. See the CLI reference.
• Pack contract. Any git repo with a .grex/pack.yaml is a pack. Three built-in pack-types ship; the plugin API lets you add more without forking. Read the pack spec.
• Reproducible manifest. Newline-delimited JSON, schema-versioned per row. See manifest.
• MCP server built-in. grex serve speaks native MCP 2025-06-18 over stdio — every non-serve verb becomes a tool call, no custom dialect. See MCP reference.
• Parallel scheduler with a Lean4 invariant proof. Bounded semaphore
  • per-pack .grex-lock + fd-lock manifest guard; "no double-lock" is mechanised. See concurrency.
• Migration from REPOS.json meta-repos via grex import --from-repos-json. See migration.

Read next

• New here? Start with Goals then Architecture.
• Writing a pack? Read the Pack spec and Pack template.
• Driving grex from an agent? Jump to MCP and the CLI JSON output reference.
• Curious how it's built? See the engineering handbook and the roadmap.

API reference (rustdoc): grex-core · grex-mcp.

Heads up: the published crate is grex-cli; the installed binary is grex. If pemistahl's unrelated grex (regex-from-test-cases) is already on your PATH, pass --force to cargo install grex-cli or rename the other binary first.