# MCP
LLMS index: [llms.txt](/llms.txt)
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## MCP Attributes
[Model Context Protocol (MCP)](https://modelcontextprotocol.io) attributes
**Attributes:**
| Key | Stability | Value Type | Description | Example Values |
| --- | --- | --- | --- | --- |
| `mcp.method.name` |  | string | The name of the request or notification method. | `notifications/cancelled`; `initialize`; `notifications/initialized` |
| `mcp.protocol.version` |  | string | The [version](https://modelcontextprotocol.io/specification/versioning) of the Model Context Protocol used. | `2025-06-18` |
| `mcp.resource.uri` |  | string | The value of the resource uri. [1] | `postgres://database/customers/schema`; `file:///home/user/documents/report.pdf` |
| `mcp.session.id` |  | string | Identifies [MCP session](https://modelcontextprotocol.io/specification/2025-06-18/basic/transports#session-management). | `191c4850af6c49e08843a3f6c80e5046` |
**[1] `mcp.resource.uri`:** This is a URI of the resource provided in the following requests or notifications: `resources/read`, `resources/subscribe`, `resources/unsubscribe`, or `notifications/resources/updated`.
---
`mcp.method.name` has the following list of well-known values. If one of them applies, then the respective value MUST be used; otherwise, a custom value MAY be used.
| Value | Description | Stability |
| --- | --- | --- |
| `completion/complete` | Request to complete a prompt. |  |
| `elicitation/create` | Request from the server to elicit additional information from the user via the client |  |
| `initialize` | Request to initialize the MCP client. |  |
| `logging/setLevel` | Request to set the logging level. |  |
| `notifications/cancelled` | Notification cancelling a previously-issued request. |  |
| `notifications/initialized` | Notification indicating that the MCP client has been initialized. |  |
| `notifications/message` | Notification indicating that a message has been received. |  |
| `notifications/progress` | Notification indicating the progress for a long-running operation. |  |
| `notifications/prompts/list_changed` | Notification indicating that the list of prompts has changed. |  |
| `notifications/resources/list_changed` | Notification indicating that the list of resources has changed. |  |
| `notifications/resources/updated` | Notification indicating that a resource has been updated. |  |
| `notifications/roots/list_changed` | Notification indicating that the list of roots has changed. |  |
| `notifications/tools/list_changed` | Notification indicating that the list of tools has changed. |  |
| `ping` | Request to check that the other party is still alive. |  |
| `prompts/get` | Request to get a prompt. |  |
| `prompts/list` | Request to list prompts available on server. |  |
| `resources/list` | Request to list resources available on server. |  |
| `resources/read` | Request to read a resource. |  |
| `resources/subscribe` | Request to subscribe to a resource. |  |
| `resources/templates/list` | Request to list resource templates available on server. |  |
| `resources/unsubscribe` | Request to unsubscribe from resource updates. |  |
| `roots/list` | Request to list roots available on server. |  |
| `sampling/createMessage` | Request to create a sampling message. |  |
| `tools/call` | Request to call a tool. |  |
| `tools/list` | Request to list tools available on server. |  |