Limitations Fresh

Known constraints of the XMCP server. Plan around these before building.

XMCP limitations

Limitation	Detail	Implication
No streaming or webhook endpoints	These require persistent connections that do not fit the MCP request/response model	Use the X API directly (or the official SDKs) for filtered stream, volume streams, and Account Activity webhooks
Spec fetched at startup	The OpenAPI spec is loaded once when the server starts	Restart the server to pick up any API spec updates
Tokens stored in memory	OAuth tokens are not persisted across restarts	You re-run the OAuth consent flow each time the server starts

What gets excluded from tools

XMCP excludes streaming and webhook operations when generating tools:

• Endpoints with /stream or /webhooks in the path are excluded.
• Operations tagged Stream or Webhooks, or marked with x-twitter-streaming: true, are excluded.

flowchart TD
    Spec[OpenAPI spec] --> Filter{Streaming or webhook?}
    Filter -->|Yes| Excluded[Excluded from tools]
    Filter -->|No| Allow{In allow-list, if set?}
    Allow -->|Yes / no list| Tool[Becomes an MCP tool]
    Allow -->|No| Skipped[Not loaded]

Real-time data alternatives

Because streaming is excluded from MCP, use these mechanisms directly for live data:

Need	Mechanism
Real-time matching posts	Filtered Stream
High-volume sampling	Volume Streams
Account events (DMs, follows, etc.)	Account Activity webhooks / X Activity (XAA)

Operational constraints

• Rate limits apply to every tool call just as they do to direct API requests. See Rate Limits.
• Auth context matters - app-only Bearer tokens cannot perform user-context actions; you need OAuth 1.0a or OAuth 2.0 for writes.
• Compliance - respect the X Developer Agreement and Display Requirements; do not automate prohibited behavior.

Spec host note

The hosted documentation references the spec at https://api.x.com/2/openapi.json. The XMCP server fetches it from the equivalent https://api.twitter.com/2/openapi.json host at startup. Both serve the same X API v2 contract.

See also

• Tool Catalog
• Endpoint Groups
• Rate Limits
• Install XMCP