google-flow-mcp

MCP server that generates images and video on Google Flow through browser automation, so you can use your own Google AI Pro subscription instead of paying per-credit services. Ships with a Claude Code skill.

Validated end-to-end: images (Nano Banana / Imagen) and video (Veo 3.1 / Omni Flash) are generated in a real Flow project and downloaded to disk.

Adapted and hardened for the current agent-first Flow UI (and Windows) from TMSSS05/google-flow-browser-mcp.

This repository is a fork of GabrielGargiuloDev/google-flow-mcp (MIT, see LICENSE), maintained here because upstream stopped working when Google moved Flow to flow.google.com in 2026-09. See Fork changes.

flow_generate — the agent-free path

Flow's prompt bar has an Agent chip. Pressed, a language model reads the prompt, rewrites it and picks the parameters; ratio and model are account-wide defaults and no price is shown anywhere before the spend. Released, the bar exposes its own control panel — mode, ratio, model, resolution, duration, count — and prints the exact credit cost of the next click.

flow_generate drives the released state and is the preferred tool. flow_generate_image and flow_generate_video remain for the agent path.

// Costs nothing: configures, reads the price off the page, returns.
{ "prompt": "a red bicycle against a yellow brick wall",
  "mode": "image", "ratio": "9:16", "model": "Nano Banana Pro", "count": "x1" }
// -> { "credits_required": 0, "configured": "Nano Banana Pro · crop_9_16 · x1", ... }

// Same call plus auto_confirm submits that exact configuration.
{ "...": "...", "auto_confirm": true }

What it buys:

• The price before the spend. Read from the panel, so auto_confirm: false is a real quote and asking never submits. Images are 0 credits; a 720p/10s/x1 video is 15.

• Parameters that are per call and verified. Every toggle carries aria-checked and is read back after clicking, so a parameter that did not take throws instead of being reported as applied.

• The prompt reaches the model verbatim — nothing rewrites it, and the imperative wrapper the agent path needs is gone.

Three defects found while building it, all of which also affect the agent path:

• createNewProject ran its "did Flow ask for a project name?" step unconditionally. Inside a project the only [contenteditable] is the prompt box, and its confirm list included [type="submit"] — the generate button. So every new project silently generated an extra image captioned with the project name. Free for images; 15 credits a call for video.

• Taking the first media that appears after submitting returned a valid, correctly sized, entirely unrelated image — the spurious generation above landed first. The scan now waits for the set to stop growing.

• The same asset is served at several signed URLs, so comparing whole URLs downloaded one image twice. Identity is now the media id (mediaId in src/utils/media-urls.js).

Each downloaded file is reported with the title Flow gave its tile, which is what says whether the output answered the prompt.

Related MCP server: Google Flow Browser MCP

Fork changes

Upstream was written against labs.google/fx/tools/flow and no longer runs: Google moved Flow to its own domain and changed how media is served. Every fix below was measured against the live app, not inferred.

The result payload also reported ratio, model_used and credits_consumed as claims rather than measurements. They now say what actually happened, including "unknown" where the UI exposes no number.

Locale: set flowUrl to https://flow.google.com/?hl=en. Without hl=en the UI renders in the account's language and every English selector misses. Upstream's French/Italian selectors are unnecessary with the override.

What it does

Playwright connects over the Chrome DevTools Protocol to a dedicated Chrome that is logged into your Google account. It drives Flow's agent to generate media and downloads the result through the authenticated session. No API keys, no password handling — it uses your existing browser session.

Tools (17): flow_connect, flow_status, flow_account_check, flow_discover_ui, flow_generate_image, flow_generate_video, flow_download_latest, character/scene tools, flow_use_grid_architect, flow_screenshot, flow_queue_status, …

⚠️ Terms of Service

This is unofficial browser automation. There is no official Google API for Flow. The launcher starts Chrome directly so navigator.webdriver is false, which is an explicit anti-bot measure. Automating Google properties can violate Google's Terms of Service and may put your account at risk. Use at your own risk, on your own account.

Requirements

• Node.js ≥ 18

• Google Chrome (Chrome 149+ needs Playwright ≥ 1.61.1, already pinned)

• A Google account with access to Flow (Google AI Pro recommended)

Setup

npm install
cp config/flow.config.example.json config/flow.config.json
# edit config/flow.config.json → set expectedAccount and chromeUserDataDir

Start the dedicated Chrome (idempotent — launches only if needed):

powershell -File scripts/ensure-flow-chrome.ps1

First run: in that Chrome window, sign in to your Google account and click "Sign in to Flow" on labs.google (Flow uses a separate sign-in). The session is saved in the dedicated profile and reused.

Register the server with your MCP client (Claude Code, etc.):

{
  "mcpServers": {
    "google-flow": { "type": "stdio", "command": "node", "args": ["<path>/src/index.js"] }
  }
}

Restart the client afterwards (the server loads into memory at startup).

Notes that matter

• Images are effectively free against the monthly Flow credit pool; video consumes credits (Veo 3.1 Lite ~10, Fast ~20, Quality ~100; Omni Flash ~15-30 of ~1000/month). Video shows a credit-confirmation dialog which the server approves.

• Model/duration must be a valid combo or Flow's agent asks for clarification and nothing generates (e.g. Veo 3.1 Lite is 8s-only on the Pro plan; Omni Flash 4-10s).

• Flow is agent-first: prompts are wrapped imperatively so the agent generates directly instead of asking questions.

• The UI language follows your Google account; navigation selectors cover IT/FR/EN.

Claude Code skill

skill/SKILL.md is a ready-to-use skill: drop it in ~/.claude/skills/google-flow-generate/ and Claude will pick the right tool, handle Chrome startup and fallbacks automatically.

License

MIT — see LICENSE.