Eulerian MCP Integration Guide for Antigravity IDE

Eulerian MCP Integration Guide for Antigravity IDE

EULERIAN MCP
  • Antigravity IDE integration guide
  • For users without advanced technical knowledge
  • Remote connector with OAuth 2.1 · Code editor · mcp_config.json

1. What it is and how it differs from the other versions

This guide connects Antigravity IDE to Eulerian's remote MCP server. Antigravity IDE is Google's code editor (based on VS Code) with a built-in agent; it supports remote MCP servers with OAuth 2.1 authentication. You install no local server and paste no API token: the connector is added in the mcp_config.json file and you sign in with your own Eulerian account. Versus Antigravity 2.0, here the connector is managed from the editor's agent panel (the MCP Servers menu) and, as in 2.0, the OAuth sign-in includes a copy-and-paste code step.
The principle, in one sentenceA remote endpoint + OAuth sign-in: you install no local servers, store no API tokens, and the IDE never sees your password. Eulerian grants only a limited, revocable access.

What you can do with it:

  • Check last week's paid search campaign performance with a single sentence.
  • Find out which media channels drove the most conversions this month.
  • Analyse the customer journey of your highest-converting segment.
  • Get analytics insights without leaving the editor or exporting data manually.

2. Before you begin

You need these four items before continuing:
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Antigravity IDE
Download and install Antigravity IDE for your system (Windows, macOS or Linux) from  antigravity.google/download  (the "Antigravity IDE" section).
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2
A Google account
Antigravity starts with your Google account, so you need one to use the editor.
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3
Eulerian's MCP endpoint URL
It's your Eulerian API endpoint with /mcp appended. You find it in the Eulerian interface, within your account, under the "Eulerian API" section.
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4
Your Eulerian credentials
Your Eulerian username and password. You'll sign in during the OAuth step. There is no API token to paste.
Endpoint requirementsThe endpoint must be reachable over the internet and over HTTPS with a valid TLS certificate: in the IDE, the connection originates from your computer. If you have access to several grids, use the endpoint of the relevant one.

3. Step-by-step setup

Step 1 Download and install Antigravity IDE
Go to  antigravity.google/download , scroll to the Antigravity IDE section and download the build for your system (Windows, macOS or Linux). Install it like any desktop application.
The "Antigravity IDE" section of the official download page, with builds for macOS, Windows and Linux.
Step 2 Open it
Open Antigravity IDE. You'll see the editor with its agent panel on the right ("Ask anything…"). We'll manage the connector from there.
Antigravity IDE's main window, with the editor and the agent panel on the right.
Step 3 Find your MCP endpoint in Eulerian
In the Eulerian interface, within your account, open the Eulerian API section. Your API Endpoint is shown there. The MCP server URL is that same endpoint with /mcp appended:
The "Eulerian API" section: your API Endpoint (demo values). You don't need the API token for this method.
https://<your-Eulerian-API-endpoint>/mcp
You don't need the API tokenUnlike other methods, here you don't copy the API token. You only need the endpoint URL with /mcp; you'll identify yourself with your username and password during the OAuth step.
Step 4 Open "MCP Servers" from the agent panel
In the agent panel (on the right), click the three-dots "…" (Additional options) button at the top. The customization options appear; choose MCP Servers.
In the agent panel, click the three dots "…" (Additional options) and choose "MCP Servers".
Step 5 Click "Manage MCP Servers"
By default the MCP Store opens (a catalog of connectors). Since Eulerian isn't in the catalog, click "Manage MCP Servers" at the top right to add it manually.
The MCP Store opens by default; click "Manage MCP Servers" (top right).
Step 6 Open "View raw config" and add the server
In Manage MCP servers, click "View raw config" at the top right to open the mcp_config.json file. Add Eulerian's server with your endpoint and /mcp at the end, then save the file:
In "Manage MCP servers", click "View raw config" (top right) to edit the file.
{"mcpServers": {"eulerian": {"serverUrl": "https://<your-Eulerian-API-endpoint>/mcp"}}}
mcp_config.json with the "eulerian" server and its serverUrl ending in /mcp (demo endpoint).
Step 7 Force Refresh and "Authenticate" appears
After saving, the Refresh button may keep spinning (the two circular arrows don't stop). Force it by clicking it. Next to Eulerian you'll see "Error: calling initialize... Unauthorized" and the Authenticate button.
After forcing "Refresh", the "Unauthorized" notice appears next to the "Authenticate" button.
"Unauthorized" here is normalIt's the state before you sign in: you haven't done the OAuth login yet. It disappears as soon as you complete authentication in the next steps.
Step 8 Click "Authenticate" (twice)
Click Authenticate. It takes you to Settings → Customizations, where you'll again see the Eulerian connector with its Authenticate button: click it once more to launch the OAuth sign-in in your browser.
The "Authenticate" button takes you to Settings → Customizations; click "Authenticate" again there.
Step 9 Sign in to Eulerian
Eulerian's sign-in screen opens in your browser. Enter your username (Identifiant) and continue with your Eulerian password. The IDE never sees your password.
Eulerian's sign-in screen.
Step 10 Authorize access (Approve)
Eulerian shows the permissions antigravity-client requests (for example eulerian:reports.read). Review them and click "Approve" to authorize (or "Deny" to cancel).
Eulerian's authorization screen: review the permissions and click "Approve".
Grant only what's neededAlways review the permissions before approving. For read-only reports, eulerian:reports.read is enough; grant write permissions only if your use case requires it.
Step 11 Copy the code and paste it into the IDE
The browser shows a one-time code. Click Copy to Clipboard, go back to the IDE and paste the code into the "Paste auth code" field (it's the same box as in Antigravity 2.0, in the editor's dark theme); then click Submit.
Antigravity shows a one-time code: copy it with "Copy to Clipboard" (code hidden) and paste it into the IDE.
Step 12 Connector connected
The Eulerian connector turns green with a Sign out button and shows the number of enabled tools (for example "133 tools enabled"). It's now connected.
The "Eulerian" connector connected (green dot, "Sign out") with its tools enabled.
Connection completeNo local servers installed and no API tokens stored. You can revoke access at any time with "Sign out" or from your Eulerian account.
Step 13 Choose which tools to enable (optional)
From Manage MCP servers → Configure, the IDE lets you enable or disable each of the 134 tools from Eulerian with its own toggle. This is useful to limit the connector to just what you need (for example, keep the reporting tools on and turn the rest off).
In "Configure" you can enable/disable each of Eulerian's 134 tools individually.
Step 14 Use it
In the agent panel, ask in natural language. The IDE will call Eulerian's tools based on what you ask, for example:
Which Eulerian tools do you have access to, and what websites are in my account?
The IDE's agent replies using Eulerian's MCP, listing the available tools and websites.

4. Teams and organisations

Antigravity stores the MCP configuration in the mcp_config.json file on your computer, and authentication is individual: each user signs in with their own Eulerian account.
  • The connector is defined in your mcp_config.json (global at ~/.gemini/config/mcp_config.json or per project in .agents/mcp_config.json).
  • Each user connects with their own Eulerian account, so they only access the data their account can see.
  • In corporate environments, confirm with your IT department which AI tools are approved for processing business data.
The access granted is limited and revocable: you can disconnect it with "Sign out" in the IDE or revoke it from your Eulerian account at any time.

5. Other clients and notes

Antigravity 2.0, the IDE and the CLI share the same MCP configuration file (~/.gemini/config/mcp_config.json). If you already added Eulerian's server on one surface, the others detect it. And because authentication is OAuth 2.1 delegated to the client, the same remote endpoint also works with Claude, ChatGPT or Mistral: Eulerian's part is always the same; only where you add the connector changes.
IDE versus Antigravity 2.0 and CLIThis guide covers the code editor (Antigravity IDE). Antigravity 2.0 is the editor-less agent app, and the CLI (agy) is driven from the terminal with the /mcp command; each has its own guide, but Eulerian's part (endpoint + OAuth) is identical.
  • Eulerian OAuth 2.1 (third-party integrations):  doc.api.eulerian.com/#section/Introduction/OAuth-2.1-for-third-party-integrations 
  • Client-specific guides: Antigravity 2.0, Antigravity CLI, Claude, ChatGPT, Mistral and "Other clients".

6. Security and best practices

OAuth instead of tokens

No API token is stored on your computer. You authenticate with your Eulerian account and Eulerian grants the IDE a limited access (for example, read-only reports) that is revocable at any time.

The authorization code is one-time

The code you copy and paste during sign-in is temporary and single-use: it only serves to complete authentication and expires quickly. It is not a token to store or share.

Enable only the tools you use

In "Manage MCP servers → Configure" you can turn off the tools you don't need. Reducing the active surface is good least-privilege practice.

Explicit, minimal permissions

Review the permissions on Eulerian's authorization screen (for example eulerian:reports.read) before clicking "Approve". Avoid write permissions if you won't use them.

Validate with your IT department

Before using real business data, confirm with IT which AI platforms are approved for processing company data.

7. If something doesn't work

Problem
Solution
I can't find where to add the connector
In the agent panel, click the three dots "…" (Additional options) → "MCP Servers" → "Manage MCP Servers" → "View raw config".
The "Refresh" button keeps spinning
This is common after editing the file: click "Refresh" to force it. The connector's status will appear (and the "Authenticate" button if you haven't signed in yet).
I see "Unauthorized" and the "Authenticate" button
That's normal before signing in. Click "Authenticate", then "Authenticate" again in Settings → Customizations, and complete the login. If "Unauthorized" persists after authenticating, contact Eulerian.
The connection won't establish or is flagged invalid
Check the URL: it must be your Eulerian API endpoint with /mcp appended, over HTTPS and with a valid TLS certificate.
Eulerian rejects the sign-in
Use your Eulerian credentials (not your Google ones). If you have access to several grids, use the endpoint of the correct one.
I pasted the code but it still won't connect
Copy the full code with "Copy to Clipboard" and paste it into "Paste auth code" before it expires; if it expires, start again from "Authenticate".
The agent says it has no access to the MCP
Check the connector is green ("Sign out") and that the tools you need are enabled in "Configure". Open a new conversation and ask again.

8. Additional resources

  • Your API endpoint: in the Eulerian interface, "Eulerian API" section (append /mcp).
  • Eulerian MCP Server documentation:  doc.eulerian.com/p/NhupKnGmQtUv_E/MCP-Server 
  • MCP in Antigravity (official docs):  antigravity.google/docs/mcp 
  • Eulerian OAuth 2.1 (third-party integrations):  doc.api.eulerian.com/#section/Introduction/OAuth-2.1-for-third-party-integrations 
  • Antigravity download:  antigravity.google/download 
  • GitHub repository:  github.com/EulerianTechnologies/eulerian-marketing-platform-mcp