General Guide to Integrating Eulerian MCP Using OAuth

General Guide to Integrating Eulerian MCP Using OAuth

EULERIAN MCP
  • Integration guide — Other clients (OAuth)
  • For users without advanced technical knowledge
  • Remote connector with OAuth 2.1 · valid for any MCP-compatible client

1. What this guide is

Almost every MCP-compatible AI assistant connects to Eulerian the same way: you add a remote connector with Eulerian's MCP server URL and sign in via OAuth 2.1. The only thing that changes from one client to another is where you add that connector. This general guide describes the common process; if you use Claude, ChatGPT, Gemini or Mistral, you also have a dedicated, illustrated guide.
The pattern common to all clients: a remote connector + OAuth sign-in at Eulerian.
The principle, in one sentenceA remote endpoint + OAuth sign-in: nothing to install, no terminal, no token to paste, and the client never sees your password. Eulerian grants only a limited, revocable access.

2. Requirements: what your client must support

To connect with this method, the AI client must meet these criteria:
  • Supports remote MCP servers (custom connectors), not just local servers.
  • Supports OAuth 2.1 as an authentication method; ideally with dynamic client registration, so you don't have to create a Client ID/Secret by hand.
  • Lets you enter a Server URL (remote endpoint) reachable over HTTPS with a valid TLS certificate.
  • The connection originates from the AI provider's servers, so the endpoint must be reachable over the internet (not behind a firewall or VPN).
  • Uses MCP's standard transport (Streamable HTTP).
Eulerian's MCP serverThe connector relies on Eulerian's MCP server, developed by Eulerian. It exposes the platform's tools and delegates authentication to OAuth 2.1, so each user only accesses the data their Eulerian account is allowed to see.

3. Compatible agents

As examples, these clients currently meet the requirements above. Eulerian's part (endpoint + OAuth) is identical; only where you add the connector changes:
Agent
Remote MCP
OAuth 2.1
Where you configure it
Claude (web and desktop)
Yes
Yes
Settings → Connectors (or one-click .dxt extension on desktop)
ChatGPT
Yes
Yes
Settings → Apps → Advanced settings → Developer mode
Google Gemini
Yes
Yes
Gemini console/admin, depending on edition (verify)
Mistral (Vibe)
Yes
Yes
Mistral Studio → Connectors; enable per conversation
Other MCP clients
Depends on client
Depends on client
Client interface or configuration file
Availability and menu names may change over time and depend on your plan or organisation. If a client isn't listed here, check its documentation to confirm it meets the requirements in Section 2.

4. Before you begin

You need these items before continuing:
Title
Title
1
A compatible AI client
An assistant that meets the requirements in Section 2 (remote MCP + OAuth 2.1).
Title
Title
2
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 (see the box below).
Title
Title
3
Your Eulerian credentials
Your Eulerian username and password. You'll sign in during the OAuth step. There is no API token to paste.
Title
Title
4
Organisation permissions (if applicable)
In some clients with team/enterprise accounts, an administrator must enable custom connectors or add the connector at the organisation level.
https://<your-Eulerian-API-endpoint>/mcp
How to get your endpointIn the Eulerian interface, within your account, go to the "Eulerian API" section: your API endpoint is shown there. The MCP server URL is that same endpoint with /mcp appended.

5. The process step by step (OAuth)

The steps are the same in any client; only where you find the connectors section in step 1 changes.
Step 1 Find where connectors are added
In your AI client, look for the connectors section (it may be called Connectors, Conectores or Apps). Some clients require you to first turn on a developer mode or to have administrator permissions.
Step 2 Add a remote connector with the endpoint URL
Choose to add a custom connector / remote MCP server and paste Eulerian's endpoint URL with /mcp appended (see Section 4).
Step 3 Choose OAuth as authentication
Select OAuth 2.1 as the authentication method. In many clients it's auto-detected from the URL; leave the Client ID/Secret blank unless Eulerian tells you otherwise.
Step 4 Sign in to Eulerian
The client redirects you to Eulerian's sign-in screen. Enter your Eulerian username and password. You paste no token here: the client never sees your password.
Step 5 Authorize access (Approve)
Eulerian shows the requested permissions (for example eulerian:reports.read). Review them and click "Approve" to authorize (or "Deny" to cancel).
Example of Eulerian's authorization screen; the client name and permissions may vary.
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 6 Enable it and use it
The connector is now connected. Some clients also require you to enable it in each conversation (in the tools menu). Then ask in natural language, for example:
Which Eulerian tools do you have access to?
Connection completeNothing installed and no tokens pasted. You can revoke access at any time from your client or from your Eulerian account.

6. Where you configure it in each client

Eulerian's part is always the same; this is just a map of where each platform adds the connector. For the illustrated detail, see the specific guide for each client:
  • Claude (web): Settings → Connectors → "Add custom connector".
  • Claude (desktop): manual method or one-click .dxt extension.
  • ChatGPT: Settings → Apps → Advanced settings → Developer mode → "Create app".
  • Google Gemini: in the Gemini console/admin, depending on the edition (verify).
  • Mistral (Vibe): create it in Mistral Studio → Connectors; then enable it in each conversation.
  • CLI/IDE clients (Codex, VS Code + Copilot, Mistral Vibe CLI, Gemini CLI): configured via a configuration file; see each one's guide.

7. Security and best practices

OAuth instead of tokens

No token is stored on your computer or in the browser. You authenticate with your Eulerian account and Eulerian grants the client a limited access that is revocable at any time.

Explicit, minimal permissions

Review the permissions on Eulerian's authorization screen before clicking "Approve" and grant only what's needed. Avoid write permissions if you won't use them.

Trusted connectors only

Only add MCP servers from developers you trust. Always verify the origin of the URL: here, the developer is Eulerian.

Reachable, secure endpoint

The endpoint must respond over HTTPS with a valid TLS certificate and be reachable over the internet, since the connection leaves the AI provider's servers.

Validate with your IT department

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

8. If something doesn't work

Problem
Solution
I can't find where to add a connector
Look for "Connectors" or "Apps" in the client's settings. Some require turning on a developer mode or administrator permissions (see Sections 3 and 6).
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.
The connection doesn't reach the server
The endpoint must be reachable over the internet: the connection leaves the AI provider's servers, not your computer. If it's behind a firewall or VPN, it won't connect.
Eulerian rejects the sign-in
Use your Eulerian credentials (not the AI client's). If you have access to several grids, use the endpoint with the correct parameter.
"Permission denied" after authorizing
On Eulerian's authorization screen you must click "Approve" (not "Deny"). If you clicked "Deny", repeat the connection flow.
The assistant says it has no access to the MCP
Some clients require enabling the connector in each conversation (tools menu). Enable it and ask again.

9. Additional resources

  • Your API endpoint: in the Eulerian interface, "Eulerian API" section (append /mcp).
  • Eulerian OAuth 2.1 (third-party integrations):  doc.api.eulerian.com/#section/Introduction/OAuth-2.1-for-third-party-integrations 
  • Eulerian MCP Server documentation:  doc.eulerian.com/p/NhupKnGmQtUv_E/MCP-Server 
  • GitHub repository:  github.com/EulerianTechnologies/eulerian-marketing-platform-mcp 
  • Client-specific guides: Claude (web and desktop), ChatGPT, Gemini and Mistral.