Service Registry (_mr.json)

_mr.json lives at the repo root and tells the gb CLI which directories belong to which services. It replaces hardcoded service lists so you can adapt the CLI to any monorepo layout without touching source code.

File format

{
  "root": "/Users/you/gbv2",
  "services": [
    { "name": "frontend",       "paths": ["frontend"] },
    { "name": "backend",        "paths": ["backend"] },
    { "name": "ci",             "paths": [".github", "infrastructure"] },
    { "name": "docs",           "paths": ["docs"] }
  ],
  "protectedBranches": ["main", "master", "staging"]
}

services

An array of service definitions. Each entry has:

Field	Type	Description
name	string	The service name shown in selectors and used in commit messages
paths	string[]	Directory prefixes that belong to this service

A file is matched to a service when its path starts with any entry in paths. If no match is found, the file falls under the built-in root service.

Multi-path services allow logically grouping unrelated directories under one name:

{ "name": "ci", "paths": [".github", "infrastructure"] }

Running gb commit and selecting ci will stage and commit all changed files under both .github/ and infrastructure/ in a single commit.

Backwards compatibility: Plain strings are also accepted and treated as { name: entry, paths: [entry] }:

"services": ["frontend", "backend"]

root

Optional. When set, all gb commands use this path as the monorepo working directory instead of auto-detecting via git rev-parse --show-toplevel.

"root": "/Users/you/gbv2"

If the configured root is a subdirectory of the git root, gb commit automatically computes the relative prefix so service paths are resolved correctly against the git status output.

Manage it with:

gb service root           # show current root
gb service root set       # edit with a pre-filled prompt
gb service root clear     # remove and fall back to git detection

protectedBranches

Optional. Defaults to ["main", "master", "staging"] if omitted.

Branches listed here trigger automatic feature-branch creation when you run gb commit on them.

Managing services with gb service

Instead of editing _mr.json by hand, use the gb service command:

gb service               # list all registered services and their paths
gb service add           # prompts for name then paths
gb service edit          # select a service and edit its paths in-place
gb service remove        # interactive selector to pick which to remove
gb service root set      # update the monorepo root path

See gb service for full details.

How paths are resolved

constants.ts reads _mr.json at startup and builds a flat path → service name map:

frontend       → frontend
backend        → backend
.github        → ci
infrastructure → ci
docs           → docs

getServiceForPath in utils.ts walks this map and returns the first matching prefix. Any file that doesn't match falls through to root.

Commit path resolution

git status --porcelain always returns paths relative to the git root. When root in _mr.json is a subdirectory of the git root, gb commit computes a rootPrefix (e.g. gbv2/) and prepends it to service paths when filtering files. The prefix is stripped again before calling git add, since git runs with cwd set to the configured root.

When root matches the git root (the typical case), the prefix is empty and there is no difference in behaviour.

This means:

• Adding a service to _mr.json immediately changes how gb status, gb commit, and gb diff group files
• Renaming a service's name only affects display and commit message format - the paths stay the same
• A file can only belong to one service (first prefix match wins)

Example: grouping CI and infrastructure

Before:

{ "name": ".github", "paths": [".github"] },
{ "name": "infrastructure", "paths": ["infrastructure"] }

After merging into one service:

{ "name": "ci", "paths": [".github", "infrastructure"] }

Now gb commit → ci stages changes from both directories under a single feat(ci): ... commit, and gb status shows them grouped together.