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

# MCP servers

> Save a reviewed MCP endpoint and credential reference, configure approval intent, and attach the server to an agent version.

Model Context Protocol, or MCP, gives external servers a common way to describe tools. Threetone can store an MCP server configuration and its agent attachment. Review who operates the server and what it can access before saving it.

<Note>
  The current **Test Connection** button is disabled, and server tool discovery returns an unavailable result. Saving the server is a configuration operation. It does not verify transport connectivity, tool discovery, approvals at runtime, or execution.
</Note>

<Frame caption="Recording pending: Review and save an MCP server configuration. Follow the written guide below.">
  <img src="https://mintcdn.com/threetonelabs-c2efc9c8/RV32i5440UZIaFHA/images/tutorials/recording-pending.webp?fit=max&auto=format&n=RV32i5440UZIaFHA&q=85&s=55f66d2eef49d8c92c9ac46f84bace35" alt="Recording pending for MCP server configuration. No playable video is available yet." width="1600" height="900" className="w-full h-auto aspect-video" loading="lazy" noZoom data-path="images/tutorials/recording-pending.webp" />
</Frame>

## Before you begin

Have a documented endpoint, its supported transport, its operator, and its authentication requirements. Use an account allowed to manage workspace tools. Keep credentials in the supported [auth-connection](/agents-platform/configure/authentication/auth-connections) or [secret](/agents-platform/configure/authentication/secrets) workflow.

## Save the configuration

<Steps>
  <Step title="Open the server form">
    Open [Integrations](https://threetone.in/app/agents/integrations) and select **Add MCP server**. Enter a useful **Name** and an optional **Description**.
  </Step>

  <Step title="Set the endpoint and transport">
    Set **Transport Protocol** to the server's documented **Server-Sent Events (SSE)** or **Streamable HTTP** transport. Enter the **Server URL** and select an appropriate auth connection if required. Review any configured request headers and metadata.
  </Step>

  <Step title="Review approval intent">
    Review the tool approval mode and other settings against the actions this server exposes. A stored approval policy does not establish runtime enforcement. Avoid granting broad mutation access merely to simplify configuration.
  </Step>

  <Step title="Acknowledge the operator and save">
    Select **I trust this server** only after reviewing its operator and data access. Threetone does not verify custom servers through that checkbox. Select **Add Server**, then reopen the entry to inspect the saved endpoint, transport, credential reference, and identifier.
  </Step>
</Steps>

<Frame caption="Screenshot pending: Add MCP server showing endpoint, transport, auth reference, and approval mode, with private values hidden.">
  <img src="https://mintcdn.com/threetonelabs-c2efc9c8/-FnvNeuT_PFanG1t/images/placeholders/screenshot-pending.svg?fit=max&auto=format&n=-FnvNeuT_PFanG1t&q=85&s=b29809bcbd6979cc43ace35853669b46" alt="Screenshot pending for MCP server configuration. This illustration is not a product screenshot." width="1600" height="1000" className="w-full h-auto" loading="lazy" noZoom data-path="images/placeholders/screenshot-pending.svg" />
</Frame>

## Attach the server

The agent's **Tools > MCP** tab currently opens the workspace server list and its details. Selecting an entry there does not save an agent attachment.

Use [Update agent](/api-reference/agents-platform/update-agent) with an explicit `branch_id` to author `conversation_config.agent.prompt.mcp_server_ids`. Preserve the intended existing server references when replacing that list. Read the selected branch and resulting version back to confirm the saved identifier. Follow [versions and drafts](/agents-platform/deploy/versioning) when reviewing a complete server draft.

Shared server configuration changes and agent publication are separate actions. Review agents that reference a server before changing or removing it. Retain a server-side record of the resource IDs your integration needs.

## Plan execution verification

When discovery and execution are released, confirm the actual tools and schemas returned by the server. Test credential scope, read and write permissions, required confirmations, endpoint failures, and changed tool definitions. Instructions returned by an external server do not override your application's access policy.

The [Create MCP server](/api-reference/agents-platform/create-mcp-server) and [Update MCP server configuration](/api-reference/agents-platform/update-mcp-server-configuration) pages describe the committed public schemas. Check operation permissions before using a programmatic credential.

## Frequently asked questions

<AccordionGroup>
  <Accordion title="Does Add Server test the endpoint?" id="faq-mcp-saving">No. The reviewed create path stores the configuration. The disabled Test Connection control and unavailable tool discovery must not be interpreted as successful tests.</Accordion>
  <Accordion title="Does I trust this server mean Threetone verified it?" id="faq-mcp-trust">No. You acknowledge the custom server's operator and intended access. Review the provider independently before sending data or credentials.</Accordion>
  <Accordion title="Is a saved approval policy sufficient?" id="faq-mcp-approval">No. Confirm enforcement and the actual tool contract when the execution path is released. Storing a policy alone does not demonstrate a confirmation step.</Accordion>
</AccordionGroup>


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