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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 retired on August 18, 2026), 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 retired on August 18, 2026. 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: v1.1.0 covers all 13 GA (v1) Merchant API sub-APIs, including Loyalty Customers. 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 [email protected] --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 123456789
gmc accounts list --access direct --filter 'accountName = "*store*"'
gmc accounts create-test 123456789 --name "Test" --time-zone Europe/Paris --language en-USThe 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 update en~US~SKU1 --data-source 11223344 --file patch.json --update-mask price,availability
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>Manage tier associations through Google's privacy-preserving, write-only GA API. Customer identifiers are read from a protected file or stdin, never from command-line flags.
gmc loyalty-customers manage --file customer.jsonPull 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, policy / disapproval triggers, and SEO optimization (31 rules across four families).
Every command supports --json and uses classed exit codes, so pipelines can branch on the failure type.
# GitHub Actions — preflight gate with annotations + job summary
- uses: yasserstudio/gmc@v1
with:
args: "--dir feeds --strict"The GitHub Action runs preflight with inline PR annotations, a job summary of findings, and structured outputs (ok, scanned, errors, warnings, report). For authenticated commands:
- uses: yasserstudio/gmc@v1
with:
command: reports check
account: "123456789"
credentials: ${{ secrets.GMC_SERVICE_ACCOUNT_KEY }}
args: "--metric clicks --min 100"| 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.
gmc mcp starts a Model Context Protocol server over stdio — AI assistants like Claude Desktop, Cursor, and VS Code Copilot can call gmc tools directly.
{
"mcpServers": {
"gmc": {
"command": "gmc",
"args": ["mcp"]
}
}
}12 tools: doctor, accounts_list, accounts_get, products_list, products_get, products_insert, products_delete, datasources_list, issues_account, quota_list, reports_query, preflight. See the MCP reference.
A TypeScript monorepo (pnpm + Turborepo). Only @gmc-cli/cli is published; its release bundle contains the internal workspace packages, which remain available to contributors as typed modules inside the monorepo.
| 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-cli/mcp |
MCP server — expose gmc tools to AI assistants |
GMC launched at v1.0.0 and follows semantic versioning: fixes ship as patches, while substantial backward-compatible API coverage can ship as a minor release.
| 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 |
✅ |
| 11 | v1.0.15 | DX — GitHub Action (annotations + summary), MCP server (12 tools for AI assistants), SEO preflight rules | ✅ |
| 12 | v1.0.16 | ordertracking — order tracking signals (last GA sub-API; v1 surface complete) |
✅ |
| 13 | v1.0.17 | Account program participation — inspect and request program enrollment | ✅ |
| 14 | v1.1.0 | August 2026 API compatibility — Loyalty Customers GA, product patch/attributes, current inventory wire format, account filters/test accounts | ✅ |
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 · [email protected]
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.