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Sweep 27 Oct 2026 · 19:04Z Build v2.1.312 531 read Stable v2.1.308 Latest v2.1.312 Next v2.1.312 Feeds RSS JSON llms.txt llms-full.txt Unofficial
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mcp-connector changedmanaged-agents/mcp-connector

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2323 
2424Specify MCP servers in the `mcp_servers` (java, php: `mcpServers`; csharp: `McpServers`; go: `MCPServers`) array when creating an agent. Each server has a `type` (csharp, go: `Type`) of `url`, a unique `name` (csharp, go: `Name`), and a `url` (csharp: `Url`; go: `URL`). No authentication tokens are provided at this stage.
2525 
26Each declared server also needs a matching `mcp_toolset` entry in the `tools` (csharp, go: `Tools`) array. The toolset's `mcp_server_name` (java, php: `mcpServerName`; csharp: `McpServerName`; go: `MCPServerName`) must match the server's `name` (csharp, go: `Name`).
26Each declared server also needs a matching `mcp_toolset` entry in the `tools` (csharp, go: `Tools`) array. The toolset’s `mcp_server_name` (java, php: `mcpServerName`; csharp: `McpServerName`; go: `MCPServerName`) must match the server’s `name` (csharp, go: `Name`).
2727 
2828<CodeGroup defaultLanguage="CLI">
2929 ```bash cURL
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270270 
271271When starting a session, pass `vault_ids` (java: `vaultIds`; php: `vaultIDs`; csharp: `VaultIds`; go: `VaultIDs`) to provide credentials for your MCP servers. Vaults are collections of credentials that you register once and reference by ID. See [Authenticate with vaults](https://platform.claude.com/docs/en/managed-agents/vaults) for how to create vaults and manage credentials.
272272 
273With a `limited` [environment](https://platform.claude.com/docs/en/managed-agents/environments#networking), session creation fails with a 400 error when the agent declares an MCP server whose host is not in `allowed_hosts` (java, php: `allowedHosts`; csharp, go: `AllowedHosts`). Setting `allow_mcp_servers` (java: `allowMcpServers`; php: `allowMCPServers`; csharp: `AllowMcpServers`; go: `AllowMCPServers`) to `true` in the environment's networking turns this check off.
273With a `limited` [environment](https://platform.claude.com/docs/en/managed-agents/environments#networking), session creation fails with a 400 error when the agent declares an MCP server whose host is not in `allowed_hosts` (java, php: `allowedHosts`; csharp, go: `AllowedHosts`). Setting `allow_mcp_servers` (java: `allowMcpServers`; php: `allowMCPServers`; csharp: `AllowMcpServers`; go: `AllowMCPServers`) to `true` in the environment’s networking turns this check off.
274274 
275275<CodeGroup>
276276 ```bash cURL
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356356 ```
357357</CodeGroup>
358358 
359Credentials are matched by URL, so the vault must contain a credential whose `mcp_server_url` (java: `mcpServerUrl`; php: `mcpServerURL`; csharp: `McpServerUrl`; go: `MCPServerURL`) refers to the same server as the `url` (csharp: `Url`; go: `URL`) declared in `mcp_servers` (java, php: `mcpServers`; csharp: `McpServers`; go: `MCPServers`). Both URLs are normalized before matching (scheme and host lowercased, default ports and trailing slashes stripped), so differences in host casing, a default port, or a trailing slash don't prevent a match; a different path, subdomain, or non-default port does. If none matches, the connection is attempted unauthenticated. See [Add a credential](https://platform.claude.com/docs/en/managed-agents/vaults#add-a-credential) for the `static_bearer` and `mcp_oauth` credential types.
359Credentials are matched by URL, so the vault must contain a credential whose `mcp_server_url` (java: `mcpServerUrl`; php: `mcpServerURL`; csharp: `McpServerUrl`; go: `MCPServerURL`) refers to the same server as the `url` (csharp: `Url`; go: `URL`) declared in `mcp_servers` (java, php: `mcpServers`; csharp: `McpServers`; go: `MCPServers`). Both URLs are normalized before matching (scheme and host lowercased, default ports and trailing slashes stripped), so differences in host casing, a default port, or a trailing slash don’t prevent a match; a different path, subdomain, or non-default port does. If none matches, the connection is attempted unauthenticated. See [Add a credential](https://platform.claude.com/docs/en/managed-agents/vaults#add-a-credential) for the `static_bearer` and `mcp_oauth` credential types.
360360 
361361### Handle connection and authentication failures
362362 
363Session creation does not validate MCP connectivity or credentials. It does check each declared server's host against the environment's networking: with a `limited` environment, session creation fails with a 400 error when a host is not allowed, as described under [Provide authentication at session creation](https://platform.claude.com/docs/en/managed-agents/mcp-connector#provide-authentication-at-session-creation). If an MCP server is unreachable or rejects the supplied credential, the session still starts and interaction remains possible. A [`session.error`](https://platform.claude.com/docs/en/managed-agents/reference#event-types) event is emitted with the `mcp_server_name` (java, php: `mcpServerName`; csharp: `McpServerName`; go: `MCPServerName`) of the affected server and a `retry_status` (java, php: `retryStatus`; csharp, go: `RetryStatus`):
363Session creation does not validate MCP connectivity or credentials. It does check each declared server’s host against the environment’s networking: with a `limited` environment, session creation fails with a 400 error when a host is not allowed, as described under [Provide authentication at session creation](https://platform.claude.com/docs/en/managed-agents/mcp-connector#provide-authentication-at-session-creation). If an MCP server is unreachable or rejects the supplied credential, the session still starts and interaction remains possible. A [`session.error`](https://platform.claude.com/docs/en/managed-agents/reference#event-types) event is emitted with the `mcp_server_name` (java, php: `mcpServerName`; csharp: `McpServerName`; go: `MCPServerName`) of the affected server and a `retry_status` (java, php: `retryStatus`; csharp, go: `RetryStatus`):
364364 
365365| Error type | Meaning |
366366| --------------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
from line 367
367367| `mcp_connection_failed_error` | The MCP server could not be reached (network error, timeout, or non-authentication HTTP failure). |
368368| `mcp_authentication_failed_error` | Authentication with the MCP server failed: the server rejected the credential from the attached vault, the server required authentication when no matching credential was configured, or an OAuth token refresh failed. |
369369 
370You can decide whether to block further interaction on this error, trigger a credential rotation, or let the session continue without the affected server's tools. The connection is retried on the next `session.status_idle` to `session.status_running` transition.
370You can decide whether to block further interaction on this error, trigger a credential rotation, or let the session continue without the affected server’s tools. The connection is retried on the next `session.status_idle` to `session.status_running` transition.
371371 
372372## Next steps
373373 
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