> ## Documentation Index
> Fetch the complete documentation index at: https://docs.costgraph.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# MCP servers

> Let GraphAI and workflows call the tools on your own MCP servers

Connect an MCP server, such as an internal tools server or a vendor's hosted
server. GraphAI and workflows can then call its tools next to CostGraph's own.
CostGraph keeps the server's credentials and sends them with each call. They don't
reach the model or the workflow sandbox.

## Before you begin

* A CostGraph organization owner, admin, or billing admin to connect the server.
* The server's public HTTPS address. CostGraph speaks the Streamable HTTP
  transport and can't reach a server on a private or internal address.
* A token for the server, or an account that can sign in to it, if the server
  needs one.

## Connect a server

<Steps>
  <Step title="Open the MCP server integration">
    Open **Settings > Integrations**, choose **MCP server**, and click
    **Connect**.
  </Step>

  <Step title="Describe the server">
    Enter a **Name** and the **Server URL**. GraphAI, workflows, and approvals
    show the name.
  </Step>

  <Step title="Choose how CostGraph authenticates">
    Choose **No authentication** or **Token**. CostGraph sends a token as
    `Authorization: Bearer`. To send it in another header, such as
    `X-API-Key`, enter that header name.
  </Step>

  <Step title="Connect">
    Click **Connect**. CostGraph lists the server's tools before it saves the
    connection.
  </Step>
</Steps>

If the server asks you to sign in, the dialog shows **Sign in**. Click it and
approve access on the server's sign-in page. Add a **Client ID** first only if
the server says it needs one. CostGraph renews the sign-in on its own.

## What the tools are available to

* **GraphAI** calls the tools while it answers your questions.
* **Workflows** call the tools while they work toward a goal. Turn off
  **Use in workflows** on the connection to keep a server out of every workflow.
* **External MCP clients**, such as Claude Desktop, see the tools when they
  connect to the [CostGraph MCP server](/costgraph/mcp/install).

Each tool's name starts with the connection's name, so tools from different
servers don't collide.

## Read-only and change tools

Every tool is either read-only or a change. A tool starts read-only when the
server marks it read-only. Every other tool starts as a change.

Read-only tools run as soon as GraphAI or a workflow calls them. Change tools
ask first:

* A workflow stops for [approval](/costgraph/workflows/approvals). The approval
  shows the server, the tool, and the exact arguments it sends. The change is
  rated **High** and can't be undone, so it waits for a person even when the
  goal allows any change.
* GraphAI shows you the call in the chat and asks you to confirm it first.
* An external MCP client marks the tool as one that can change something, and
  asks you before it calls it.

Only an organization owner or admin can run a change tool from GraphAI or an
external MCP client.

## Manage a connection

On the connection, click **Settings** to do the following:

* Turn **Enabled** off for a tool you want to keep out of reach.
* Turn **Read-only** on or off to decide which tools need approval.
* Turn **Use in workflows** off to keep the server in GraphAI only.
* Click **Reconnect** to list the server's tools again, or to sign in again.
  For a server with a token, enter a new token first to replace the old one.

Click **Disconnect** on the connection to remove the server and its tools.

## Fix connection errors

* **The server did not respond.** Check that the server is reachable from the
  internet at the address you entered.
* **The server refused CostGraph's credentials.** Open the connection's
  **Settings**, enter a new token or sign in again, and click **Reconnect**.
* **The address points to a private or internal address.** Use the server's
  public address.


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