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Discovery changedspecification/2026-07-28/server/discover

Nearest release: v2.1.305, published under an hour before upstream edited the page. Shown because the two are within 24 hours of each other. Nothing here says the release caused the edit.

Upstream edited this page at 20 Oct 2026 20:02 UTC, give or take a minute or two: the time comes from Anthropic’s own sitemap rather than from a commit. This site recorded the change at 22 Oct 2026 20:37 UTC.

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2929## Response
3030 
3131The server replies with its supported protocol versions, capabilities, and
32identity. This operation supports [caching](/specification/2026-07-28/server/utilities/caching).
32identity. This operation supports [caching](/specification/2026-07-28/server/utilities/caching.md).
3333 
3434```json theme={null}
3535{
from line 73
7373 HTTP status code to drive fallback. A client that supports both modern
7474 (per-request `_meta`) and legacy (`initialize` handshake) servers **SHOULD**
7575 send `server/discover` first; see
76 [stdio: Backward Compatibility](/specification/2026-07-28/basic/transports/stdio#backward-compatibility)
76 [stdio: Backward Compatibility](/specification/2026-07-28/basic/transports/stdio.md#backward-compatibility)
7777 for the fallback rules.
7878 
79See [Protocol Version Negotiation](/specification/2026-07-28/basic/versioning#protocol-version-negotiation)
79See [Protocol Version Negotiation](/specification/2026-07-28/basic/versioning.md#protocol-version-negotiation)
8080for the full version-selection flow. For HTTP-specific status codes returned for
81unknown methods, see the [Protocol Version Header](/specification/2026-07-28/basic/transports/streamable-http#protocol-version-header)
81unknown methods, see the [Protocol Version Header](/specification/2026-07-28/basic/transports/streamable-http.md#protocol-version-header)
8282section in Transports.
8383 
8484## Data Types
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