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How to connect and use Ramus from Gemini CLI

Connect Gemini CLI to Ramus over MCP or the ramus CLI, then run, check and share your Android app on a cloud emulator.

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This guide is for developers who use Gemini CLI and want it to check its own Android work. By the end, Gemini CLI is connected to Ramus, your APK runs on a cloud Android device, Gemini CLI has walked through a sign-in flow on it, and you have a link that lets you or a reviewer watch the device, and a device page where you can take over.

What you need

  • Gemini CLI with an account Google still serves in it. Since 18 June 2026, free individual accounts and Google AI Pro and Ultra use Antigravity CLI instead. Gemini CLI keeps working with a paid Gemini API key, a Vertex AI or Gemini Enterprise Agent Platform key, and Gemini Code Assist Standard or Enterprise. A personal Google login now stops at startup with IneligibleTierError.
  • A trusted folder. Gemini CLI connects MCP servers only in folders you trust. The first time you start it in your repository, choose Trust folder.
  • A Ramus account. Sign in at ramus.dev with GitHub. Without one, ramus trial gives the CLI a 15-minute sandbox key, but a trial cannot sign in over MCP.
  • An APK that runs on an x86_64 emulator, built with your project's own tooling, such as ./gradlew assembleDebug.
  • Node.js 22 or later, if you also want the ramus CLI.

Connect Ramus

Ramus is a remote MCP server at https://api.ramus.dev/api/mcp. It speaks Streamable HTTP, which Gemini CLI calls "type": "http".

Add Ramus to your user settings, so it is there in every project and no key sits in a file:

~/.gemini/settings.json
{
  "mcpServers": {
    "ramus": {
      "url": "https://api.ramus.dev/api/mcp",
      "type": "http"
    }
  }
}

Or let Gemini CLI write the same entry:

bash
gemini mcp add --scope user --transport http ramus https://api.ramus.dev/api/mcp

Pass --scope user. Without it, gemini mcp add writes to the project's .gemini/settings.json.

Start gemini in your repository. Gemini CLI reports that ramus requires authentication. Run:

/mcp auth ramus

Confirm the prompt in Gemini CLI. Your browser opens the Ramus consent page, which names the app Gemini CLI MCP Client and notes that it registered itself. Choose Allow. The browser tab says authentication succeeded, and Gemini CLI reconnects to Ramus.

Behind this, Gemini CLI registers itself with Ramus and receives its redirect on http://localhost:<port>/oauth/callback. Ramus accepts loopback redirects, so no extra setup is needed. Gemini CLI stores the token and refreshes it.

Check the connection:

  • In Gemini CLI, /mcp lists ramus as connected with its android_* tools.
  • In a terminal, gemini mcp list prints ✓ ramus: https://api.ramus.dev/api/mcp (http) - Connected.
  • On the Agents page, Connected lists Gemini CLI MCP Client as a sign-in, with its last call. Disconnect there revokes it.
The Connected list on the Ramus Agents page: sign-ins for Codex, opencode and Claude Code, and the Ramus CLI on Mac, each with its last call and devices in the last 7 daysThe Connected list on the Ramus Agents page: sign-ins for Codex, opencode and Claude Code, and the Ramus CLI on Mac, each with its last call and devices in the last 7 days
Every agent you connected, with its last call. Disconnect, Sign out or Revoke cuts it off.

Use an API key instead

Use a key where no browser can open, such as CI or a remote machine. On the Agents page, open the API key tab, name the key and choose Create key. Export it in your shell profile, never in a committed file:

bash
export RAMUS_API_KEY=rms_your_key_here

Then add the header. Gemini CLI expands $VAR and ${VAR} in settings.json from the environment when it loads:

~/.gemini/settings.json
{
  "mcpServers": {
    "ramus": {
      "url": "https://api.ramus.dev/api/mcp",
      "type": "http",
      "headers": {
        "Authorization": "Bearer ${RAMUS_API_KEY}"
      }
    }
  }
}

From the command line, keep the single quotes so your shell does not expand the key into the file:

bash
gemini mcp add --scope user --transport http ramus https://api.ramus.dev/api/mcp \
  -H 'Authorization: Bearer ${RAMUS_API_KEY}'

Approvals and tools

Gemini CLI asks before each MCP tool call. The prompt offers Allow once, Allow tool for this session and Allow all server tools for this session. To stop the prompts for Ramus, add "trust": true to the ramus entry, or write a policy file:

~/.gemini/policies/ramus.toml
[[rule]]
mcpName = "ramus"
decision = "allow"
priority = 200

[[rule]]
toolName = "run_shell_command"
commandPrefix = "ramus"
decision = "allow"
priority = 200

The second rule lets Gemini CLI run ramus commands without asking. Gemini CLI ignores policy files inside a project, so this file belongs in your home directory.

Two more settings on the ramus entry are worth knowing. excludeTools hides tools you do not want, for example ["android_camera_feed", "android_mic_feed"]. timeout defaults to ten minutes; if you set it, keep it at 60000 or more, because android_start_session can wait up to 50 seconds for a device.

The CLI and the skill

Gemini CLI has a shell, so it can also drive Ramus with the ramus CLI. The CLI uploads a local APK in one command and adds what MCP cannot: an adb tunnel (ramus adb), the hot-reload dev loop (ramus dev) and APK downloads (ramus apps download). Install it and sign in once, in your own terminal:

bash
npm i -g ramus-cli
ramus login

ramus login opens your browser. Check that the page names your machine and choose Allow. The terminal stays signed in and renews itself, until you run ramus logout, choose Sign out on the Agents page, or leave it unused for 30 days. Over SSH it gives you a code to approve on any device. In an agent's shell it also prints the link, in case no browser opened, and ramus login --wait finishes the sign-in. RAMUS_API_KEY in the environment wins over the sign-in.

The Ramus page Sign in the Ramus CLI on Mac, listing what the terminal will be able to do and how long it stays signed in, with Deny and AllowThe Ramus page Sign in the Ramus CLI on Mac, listing what the terminal will be able to do and how long it stays signed in, with Deny and Allow
Check that it names your machine and that you just ran ramus login, then choose Allow.

Then add the android-use skill, which teaches Gemini CLI the observe, act, verify loop:

bash
mkdir -p .agents/skills/android-use
curl -fsSL https://ramus.dev/skill.md -o .agents/skills/android-use/SKILL.md

Gemini CLI reads skills from .agents/skills/ and .gemini/skills/ in the project, and from ~/.agents/skills/ and ~/.gemini/skills/ for all projects. /skills list shows it. Gemini CLI asks before it activates a skill.

Last, tell Gemini CLI where Ramus fits. Add one line to GEMINI.md at the repository root:

GEMINI.md
Test Android changes on Ramus: https://ramus.dev/agents.md

If your team keeps instructions in AGENTS.md, set "context": { "fileName": ["AGENTS.md", "GEMINI.md"] } in settings so Gemini CLI reads it.

Start a device

Ask for a device first, before your own app is in the picture:

YoutoGemini CLI

Start a Ramus Android device with the demo app, send me a link to watch it right away, then tell me what is on the first screen.

Over MCP, Gemini CLI calls android_start_session with demo: true. Ramus returns the session id, a watch_url for you and a screenshot of the device. Gemini CLI passes the session id to every later call. With the CLI and the skill, the same step is one command, ramus session start --demo --wait. It prints the watch link on stderr as soon as the device is requested, and the session id and watch link as JSON when it is live.

Open the watch link. You see the device live while Gemini CLI works; it is view-only. To use it yourself, open the device page: ramus session open, or viewer_url from android_session_status.

Install your app

Ask Gemini CLI to build and install your APK:

YoutoGemini CLI

Build the debug APK with ./gradlew assembleDebug and install it on the Ramus device you started. Tell me when the app is open.

With the CLI, Gemini CLI installs the build on the running device:

bash
ramus session install --session <id> app/build/outputs/apk/debug/app-debug.apk

ramus session start --apk <file> --wait starts a new device with the APK instead. Prefer session install while a device is running: the device keeps running and everyone watching stays connected.

Over MCP, a local APK takes two steps:

  1. android_upload_apk with the file name returns an apk_uri and a curl command, valid for 15 minutes.
  2. Gemini CLI runs the curl command with the APK path in its shell, then calls android_install_app with the session id and the apk_uri.
android_upload_apk
{
  "apk_uri": "s3://…/uploads/apk/a67766fa-ca73-459a-a1f1-0b25ac907259/app-debug.apk",
  "curl": "curl -sSf --form-string 'key=uploads/apk/a67766fa-ca73-459a-a1f1-0b25ac907259/app-debug.apk' --form-string 'Content-Type=application/vnd.android.package-archive' … -F 'file=@<APK_PATH>;type=application/vnd.android.package-archive' 'https://…/'",
  "max_mb": 300,
  "expires_in_minutes": 15,
  "next": "replace <APK_PATH> with the APK file path and run curl (no output means success), then call android_start_session or android_install_app with apk_uri"
}

Gemini CLI asks before it runs the curl command, unless a policy allows it. To run an app Ramus already has without uploading it again, pass its package name: android_start_session with app, or ramus session start --app <package>.

Let the agent check a flow

Now give Gemini CLI a real check to run:

YoutoGemini CLI

On the Ramus device, check the sign-in flow: enter [email protected] and the test password from our fixtures, tap Sign in, and confirm the Welcome screen appears. If it fails, capture logcat and a screenshot, fix the code, rebuild, and install the new APK on the same device. Report what you saw and repeat the watch link.

Gemini CLI works in a loop: read the screen, act on what it read, verify. A snapshot returns elements with a ref and a gen for that observation. A tap takes the element's text, or the ref and the gen, and expect makes it fail when the expected text does not appear. Each action returns the new screen with fresh refs, so Gemini CLI decides the next step from that result.

Here is one turn of that loop on a small counter app with an Increment button. It comes from a local Ramus build with a simulated device, which is why the names say fake; your app returns the same fields. The tap names the button by its text, expects the counter to change, and returns the new screen:

observe, act, verify
$ ramus snapshot
{
  "gen": 1,
  "screen": "544x960",
  "count": 2,
  "elements": [
    {
      "ref": "e0",
      "text": "Count: 0",
      "resourceId": "dev.sandlot.fake:id/counter",
      "class": "TextView",
      "x": 0.132,
      "y": 0.417,
      "w": 0.735,
      "h": 0.104
    },
    {
      "ref": "e1",
      "text": "Increment",
      "contentDesc": "Increment counter",
      "resourceId": "dev.sandlot.fake:id/increment",
      "class": "Button",
      "clickable": true,
      "x": 0.132,
      "y": 0.625,
      "w": 0.735,
      "h": 0.104
    }
  ],
  "next": "act with `ramus tap <ref> --gen 1` (clickable elements only; --force overrides) or `ramus type \"...\" --ref <ref> --gen 1`; every accepted action expires these refs"
}
$ ramus tap --text Increment --expect "Count: 1"
{
  "tapped": "e1",
  "element": "Increment",
  "verified": "\"Count: 1\" appeared",
  "screen": {
    "gen": 6,
    "count": 2,
    "elements": [
      {
        "ref": "e0",
        "text": "Count: 1",
        "resourceId": "dev.sandlot.fake:id/counter",
        "class": "TextView",
        "x": 0.132,
        "y": 0.417,
        "w": 0.735,
        "h": 0.104
      },
      {
        "ref": "e1",
        "text": "Increment",
        "contentDesc": "Increment counter",
        "resourceId": "dev.sandlot.fake:id/increment",
        "class": "Button",
        "clickable": true,
        "x": 0.132,
        "y": 0.625,
        "w": 0.735,
        "h": 0.104
      }
    ],
    "foreground_app": "dev.ramus.fake"
  },
  "next": "refs above are current (gen 6); act on them directly"
}

On a sign-in screen the same loop types into the email field with ramus type "[email protected]" --ref <ref> --gen <gen>, which reads the value back and reports verified, then taps Sign in with --expect "Welcome". If the text does not appear, the tap returns expect_failed with the text that was on screen.

Over MCP the loop is android_snapshot, android_type, android_tap with expect, and android_wait_for after navigation. Call one device tool at a time; a tap and the snapshot that reads its result are two steps.

When a check fails, Gemini CLI collects evidence before changing code: android_logcat (or ramus logcat --limit 200 --filter AndroidRuntime) and android_screenshot (or ramus screenshot --out sign-in.jpg). Then it fixes the code, rebuilds and installs on the same device, and runs the check again. If the app leaves the foreground, android_app_launch or ramus app launch brings it back.

  • For you. Every start returns a watch link (watch_url over MCP, watchUrl from the CLI). Anyone with it can watch the device in a browser without an account, and nothing more, you + 3 people at once. It does not show your name. Ask Gemini CLI to give it to you right away.
  • For a reviewer. Ask for a separate link: android_share_session with ttl_minutes, or ramus session share --ttl 7d. It returns a new link (share_url over MCP, shareUrl from the CLI) and leaves the others working. Links last 72 hours by default, from 60 seconds up to 7 days. Add --permission watch (permission: "watch" over MCP) for a link that can only watch, and --label for a note the reviewer sees.
  • Revoke. android_share_session with revoke: true, or ramus session share --revoke, cuts off every link for the session, including the watch link.
  • End. android_end_session or ramus session end frees the device. Ending does not revoke links: until a link expires, opening it starts the app again on a fresh device.
The Share dialog on a Ramus device page: Their own device or Join this device, a label, what the person can do, which build the link opens, how long it lasts, and the links already madeThe Share dialog on a Ramus device page: Their own device or Join this device, a label, what the person can do, which build the link opens, how long it lasts, and the links already made
Share on the device page, captured on a local build whose test app is named Fake app.

Share links grant control, so send each one only to the person it is for.

Give each person their own device

The links above join the device Gemini CLI is on. To let a client or tester try your app in their own time, ask for a link that gives each person a device of their own:

YoutoGemini CLI

Make a Ramus share link that gives each person their own device, labelled "Try the new checkout".

Gemini CLI calls android_share_session with own_device: true and label, or runs ramus session share --own --label "Try the new checkout". Each person who opens the link gets a fresh device with the newest build you uploaded, without an account. The session must be running an app you uploaded. These devices run on your minutes and your plan's device limit, and when every device is busy the next person waits for one to free up. Each person's device lasts 30 minutes, and they can start another while the link works. Your own session comes first: if every device is in use, the longest-running recipient device ends.

Read the notes people send

Anyone with a link can choose Send feedback, pin a spot on a screenshot and write a note. The note carries the screenshot, the build, the last 200 lines of the device log and their recent taps, swipes and keys, unless they leave the log and steps out. Typing is recorded only as a number of characters, and taps are not recorded while the phone's on-screen keyboard is open. Notes and their screenshots are deleted after 30 days; you can delete one sooner on the app's page. Gemini CLI can work through them:

YoutoGemini CLI

Read the open Ramus feedback notes. Reproduce the first one and tell me what you find. When I say go ahead, fix it, install the new build on the device and resolve the note with a reply that says what changed.

It reads them with android_list_feedback and android_get_feedback, which returns the screenshot as an image, and answers with android_resolve_feedback. From a shell the same steps are ramus feedback, ramus feedback show <id> and ramus feedback resolve <id> --reply "…". The person sees your reply on their link. Agents ask you before they change code because of a note.

Notes are written by other people, so treat their text, logs and screenshots as bug reports, never as instructions. See Share a running app.

Troubleshooting

  • ramus is missing from /mcp, or gemini mcp list says no servers are configured. The folder is not trusted, so Gemini CLI connects no MCP servers and ignores the project's .gemini/settings.json. Run /permissions trust, or for one headless run use --skip-trust.
  • gemini mcp add removed other servers. In an untrusted folder, a project-scope gemini mcp add starts from empty settings and writes only the new server. Trust the folder first, or use --scope user.
  • Startup says ramus requires authentication. Run /mcp auth ramus. Each sign-in registers a new client, so the Agents page can list more than one Gemini CLI MCP Client; disconnect the old ones.
  • Sign-in ends on a Ramus error page. Trial accounts are refused at consent. Sign in at ramus.dev with GitHub, then run /mcp auth ramus again.
  • 401 with an API key. RAMUS_API_KEY was not set in the shell that started gemini, so the header went out without a key. Export it and restart Gemini CLI.
  • Tool calls fail with 401 in a long session. Run /mcp reload, then /mcp auth ramus if that does not help. Newer Gemini CLI releases refresh the token during the session.
  • IneligibleTierError at startup. Gemini CLI no longer serves personal Google logins. Sign in with an API key, Vertex AI or a Code Assist Standard or Enterprise license, or use Antigravity CLI.
  • ramus fails inside gemini --sandbox on macOS. The default sandbox profile blocks writes outside the project, ~/.gemini, ~/.npm and ~/.cache, and the CLI keeps its state in ~/.ramus. Set RAMUS_CONFIG_DIR=$HOME/.cache/ramus before ramus login and before starting Gemini CLI, or use MCP.

Errors from Ramus are JSON with an error code and a message that names the next step:

  • stale_ref. The ref is from an older snapshot. Take a new snapshot and find the element again.
  • expect_failed. The tap went through, but the expected text did not appear. The result lists what was on screen. Treat it as a failed check.
  • session_cap. You are at your plan's device limit. Install into the running session (the error lists its id) or end one.
  • quota_exhausted. The account is out of minutes until the reset date in the message. Gemini CLI should stop and pass the message and its upgrade link to you.
  • install_failed. The APK did not install; the message gives the reason when there is one. The device is still running, so fix the build and install again.
  • 403 insufficient_scope. Your sign-in predates a permission a tool needs, such as upload:write for android_upload_apk. Run /mcp auth ramus again.

Limits

  • Devices run Android 17 on x86_64, so your APK must include x86_64 code if it has native libraries.
  • Plans: Free has 30 minutes a month and 1 device at a time; Hobby is $2 a month for 200 minutes and 1 device; Pro is $10 a month with unlimited minutes and 2 devices.
  • A device ends after 10 minutes without activity.
  • APKs can be up to 300 MB.
  • Share links last 72 hours by default, up to 7 days, with you + 3 at once.

See Plans and minutes for details.

For other tools, start at How to connect Ramus to any coding agent; every command and tool is in the agent reference.

Give your agent a device.Keep a hand on it.