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GMC is a command-line interface for the Google Merchant API — the successor to the Content API for Shopping. It gives you typed, scriptable, CI-friendly access to your Merchant Center accounts and product catalog from a single binary, without a browser.
It is built for the Content API → Merchant API migration (the Content API is being retired), and around the three things that API makes harder than it should: catching the silent setup failures (doctor), validating feeds offline before they get disapproved (preflight), and moving off the Content API cleanly (migrate).
Install · Getting Started · CLI Reference · Roadmap
npm install -g @gmc-cli/cliSee the Installation guide for other methods.
gmc auth login # 1. sign in with your Google account (or a service-account key for CI)
gmc doctor # 2. diagnose auth, GCP registration, and Merchant API access
gmc accounts list # 3. see the accounts your credential can reach
gmc --account 123456789 products list # 4. read the catalog
gmc --account 123456789 feeds pull # 5. export it to version-controllable files
gmc preflight --dir feeds # 6. catch disapprovals offline, before you pushSet an account once in a profile and drop the --account flag.
Most Merchant Center work is still done by hand in the web UI, and the Content API that powered automation is being retired. GMC makes the move scriptable.
| GMC | Merchant Center UI | Raw API / client libs | |
|---|---|---|---|
| Typed CLI, one binary | ✅ | — | you write the code |
--json + classed exit codes |
✅ | — | DIY |
| Diagnoses the silent GCP-registration trap | ✅ doctor |
— | — |
| Catalog as version-controllable files | ✅ | — | DIY |
| Offline feed-compliance preflight | ✅ preflight |
— | — |
| Content API → Merchant API migrate | ✅ migrate |
— | — |
The differentiators — doctor, preflight, and migrate — were front-loaded, and breadth has since caught up: all 11 Merchant API sub-APIs are now covered. See the roadmap.
Four ways in, resolved in order. See Authentication.
gmc auth login # interactive OAuth (browser)
gmc auth login --no-browser # headless / remote — prints the URL
gmc auth whoami # resolved identity (no network call)
gmc auth test # confirm the credential mints a tokenFor CI, point GMC at a service-account key: export GMC_SERVICE_ACCOUNT=/path/to/key.json (or the standard GOOGLE_APPLICATION_CREDENTIALS). Application Default Credentials (gcloud auth application-default login) also work.
gmc doctor validates your credential, mints a token, and probes the Merchant API — catching the trap where a credential authenticates fine but the Cloud project was never registered, so every call returns a cryptic empty result.
gmc doctor
gmc doctor --json | jq '.checks[] | select(.status != "pass")'gmc accounts list # accounts your credential can access
gmc accounts get 123456789 # the raw account resource
gmc accounts info 123456789 # a profile: account + business info + homepage
gmc accounts update 123456789 --name "My Store" --time-zone America/New_York
gmc accounts business-info update 123456789 --file business-info.json
gmc accounts homepage set https://mystore.com 123456789 # set / claim / unclaim
gmc accounts users add jane@example.com --access-rights STANDARD,ADMIN 123456789
gmc accounts create --name "Sub" --time-zone America/New_York --language en-US --aggregator 123456789
gmc accounts delete 987654321 --yes # irreversible (--yes required)
gmc accounts autofeed update 123456789 --enable-products true
gmc accounts shipping get 123456789 --json > shipping.json # edit, then `shipping set --file`
gmc accounts return-policies list 123456789The Merchant API splits products into a read-only processed resource and a writable product input. gmc presents both under gmc products.
gmc products list --page-size 50 # processed products (status + issues)
gmc products get en~US~SKU1 # one product, with item-level issues
gmc products insert --data-source 11223344 --file product.json # create/replace
cat product.json | gmc products insert --data-source 11223344 # …or from stdin
gmc products delete en~US~SKU1 --data-source 11223344A data source is the feed your products live in. Create a primary feed (API push or scheduled fetch), then insert against it.
gmc datasources create --name "API feed" --content-language en --feed-label US
gmc datasources list
gmc datasources update <id> --name "Renamed feed"
gmc datasources fetch <id> # trigger an immediate pull (scheduled feeds)
gmc datasources delete <id>Pull your catalog to version-controllable files — one push-ready product per file — then commit, diff, review, and push back.
gmc feeds pull --dir feeds # one JSON file per product
gmc feeds diff --data-source 123 # preview what push would change
gmc feeds push --dir feeds --data-source 123Catch Merchant Center disapprovals offline, before you upload — no API call, no auth. Run it on a pulled directory, a single file, or (with --remote) the live catalog. It exits non-zero on gating findings, so it drops straight into CI.
gmc preflight --dir feeds # scan the pulled catalog
gmc preflight --json # full machine-readable reportConfigure rule severities, ignores, and strict mode in a project-local .gmcpreflightrc. The engine checks required attributes, value formats, and policy / disapproval triggers.
Every command supports --json and uses classed exit codes, so pipelines can branch on the failure type.
# GitHub Actions
- run: npm install -g @gmc-cli/cli
- env:
GMC_SERVICE_ACCOUNT: ${{ secrets.GMC_SERVICE_ACCOUNT }}
GMC_ACCOUNT_ID: "123456789"
run: |
gmc doctor --json # fail the job on a broken setup
gmc products list --json | jq '.products | length'| Code | Meaning |
|---|---|
0 |
Success |
1 |
General error |
2 |
Usage (bad arguments) |
3 |
Authentication error |
4 |
Configuration error |
5 |
Merchant API error |
6 |
Preflight found gating compliance issues |
A GitHub Action and a GitLab CI recipe are available for drop-in pipeline integration.
A TypeScript monorepo (pnpm + Turborepo). Use the gmc command, or import the packages as a typed Merchant API SDK.
| Package | Description |
|---|---|
@gmc-cli/cli |
CLI entry point — the gmc command |
@gmc-cli/core |
Command orchestration, doctor, exit-code conventions |
@gmc-cli/api |
Typed Merchant API client (rate limiter, retry, pagination) |
@gmc-cli/auth |
Authentication — service account, OAuth, ADC |
@gmc-cli/config |
Configuration loading and profiles |
@gmc-cli/preflight |
Offline feed-compliance rule engine + .gmcpreflightrc |
@gmc-cli/migrate |
Content API → Merchant API transform + feed-label checker |
GMC launched at v1.0.0 and ships small, frequent patch releases (v1.0.x) — new commands land as patches.
| Phase | Versions | Theme | Status |
|---|---|---|---|
| 0 | v0.0 | Scaffold — monorepo, gmc shell, docs site |
✅ |
| 1 | v0.1–v0.4 | Spike pt 1 — auth, CLI shell, doctor |
✅ |
| 2 | v0.5–v0.7 | Spike pt 2 — typed client, accounts, products | ✅ |
| 3 | v0.8–v0.9.2 | Feeds as code — data sources, pull, push, diff | ✅ |
| 4 | v0.9.3–v0.9.5 | Preflight — offline feed-compliance scanner | ✅ |
| 5 | v0.9.6–v0.9.8 | Migrate — Content API → Merchant API assistant | ✅ |
| 6 | v0.9.9–v0.9.10 | Inventories + promotions | ✅ |
| 7 | v0.9.11–v0.9.13 | Reports — performance, visibility, price insights | ✅ |
| 8 | v0.9.14–v0.9.16 | CI/CD — GitHub Action, GitLab recipe, exit-code hardening | ✅ |
| 9 | v0.9.17–v1.0.0 | Polish & launch → v1.0.0 | ✅ |
| 10 | v1.0.2–v1.0.14 | Feature surface — regions, account mgmt, notifications, quota, issues, conversions, lfp → all 11 Merchant API sub-APIs covered |
✅ |
Full detail in the roadmap · shipped work in the changelog · the story in the devlog.
Full docs at yasserstudio.github.io/gmc:
Free to use. Released under the MIT License.
Made by Yasser's Studio · LinkedIn · X · hello@yasser.studio
GMC is an independent project. Not affiliated with, endorsed by, or sponsored by Google LLC. "Google Merchant Center", "Google Shopping", and "Google" are trademarks of Google LLC.
