ec5b2258c9
Cut import and startup cost with deferred model builds and lazy imports
...
Every import path now pays only for what it uses, with no public API
added or removed:
- The protocol models (mcp.types / mcp_types, incl. the JSON-RPC
envelopes and the generated per-version wire packages) build their
pydantic validators on first use instead of at import (defer_build),
through one shared private base class. First-use builds are
serialised behind a single process-wide lock, since released pydantic
does not make concurrent first use of a deferred model thread-safe;
this also fixes a pre-existing concurrent-first-use failure that
reproduces on main.
- `import mcp` binds the client/server names lazily on first attribute
access (PEP 562) instead of importing both stacks eagerly, and the
client no longer imports the server, so client entry points stop
loading the server, the web stack, httpx2 and cryptography.
- The web application stack (starlette's app machinery, sse_starlette,
uvicorn) loads with the app builders that use it, and each protocol
version's wire package loads on the first message parsed for that
version rather than both loading at import.
On the fresh-interpreter harness `import mcp` is ~0.4x of v1 (main is
~1.6x), the client entry points ~0.6x of v1, `import mcp.server.mcpserver`
~0.7x, and time-to-ready / stdio cold start land at parity with v1. RSS
after `import mcp` is 19 MiB (v1 43.5, main 57). Steady-state per-call
latency is unchanged.
Observable-but-incidental differences (removed incidental namespace
bindings, deeper submodules no longer imported as a side effect of a
bare `import mcp`, get_type_hints needing localns= for a documented set
of callables, pre-first-use introspection) are catalogued in
docs/migration.md; ratchet tests pin the import footprints and the
concurrent-first-use safety.
2026-08-03 15:06:11 +00:00
a4f4ccd091
Link the released 2026-07-28 spec and point migrators at /v1/ ( #3214 )
2026-07-29 15:01:27 +01:00
6f69a3758e
Present v2 as the stable release across the README, docs, and policies ( #3178 )
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2026-07-28 14:31:36 +01:00
af06330a31
Remove unused StreamableHTTPTransport.get_session_id() ( #3205 )
2026-07-28 13:55:02 +01:00
c9c431b71a
Expose the middleware chain on MCPServer and stop sending unrequested change notifications ( #3201 )
2026-07-28 12:24:23 +01:00
528e366558
Fail fast on server-to-client requests in JSON-response mode instead of hanging ( #3195 )
2026-07-28 11:04:51 +01:00
89c5e700f2
Gate log notifications on the per-request log-level opt-in at 2026-07-28 ( #3198 )
2026-07-28 02:20:33 +01:00
b7c9a916d6
Add mcp.types as a permanent alias for mcp_types ( #3190 )
2026-07-27 23:47:04 +01:00
923341c98a
Stop answering cancelled requests ( #3188 )
2026-07-27 23:26:00 +01:00
e8ef138153
docs: fill migration-guide gaps found by automated v1-to-v2 migration runs ( #3187 )
2026-07-27 23:17:17 +01:00
d3ffe87960
Split the registration request model from the registered-client record ( #3181 )
2026-07-27 23:11:01 +01:00
b9422f1c9b
Make the per-version wire packages private (mcp_types._v*) ( #3191 )
2026-07-27 22:16:48 +01:00
11934c90ae
Replace FileResource.is_binary with an encoding field ( #3171 )
2026-07-26 00:58:06 +01:00
814072c94d
Narrow message_handler's parameter to notifications and exceptions ( #3168 )
2026-07-26 00:24:48 +01:00
47bfa85e83
Remove the unused timeout parameter from OAuthClientProvider ( #3165 )
2026-07-26 00:22:15 +01:00
3212591946
Stop advertising MCP_* env vars for MCPServer settings; drop pydantic-settings ( #3170 )
2026-07-25 23:22:27 +01:00
7163d8263f
Remove the deprecated RFC7523OAuthClientProvider ( #3169 )
2026-07-25 22:50:57 +01:00
e90a66b554
Rename scopes= to scope= on the client-credentials OAuth providers ( #3166 )
2026-07-25 20:23:36 +01:00
5dd062d077
Remove Context.client_id ( #3167 )
2026-07-25 19:11:51 +01:00
629ca297d2
Isolate the stdio server's stdin and stdout from handler subprocesses ( #3117 )
2026-07-25 13:05:51 +01:00
837ef904f8
Align with spec #3002 : optional clientInfo, serverInfo in result _meta ( #3143 )
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2026-07-23 12:00:36 +01:00
03aaebd3aa
Add Streamable HTTP request body limits ( #3095 )
2026-07-16 08:33:32 +02:00
2713b53b12
Replace httpx and httpx-sse with httpx2 ( #2972 )
...
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Co-authored-by: Max Isbey <224885523+maxisbey@users.noreply.github.com >
2026-07-14 17:05:08 +01:00
9bdc03d54e
Add the client-side subscriptions/listen driver ( #3047 )
2026-07-07 14:26:09 +01:00
d287c9868f
Extend resolver DI to sampling and roots requests ( #3049 )
2026-07-06 18:25:57 +01:00
bf4402725d
docs: restructure the migration guide around topical groups with a navigation layer ( #3058 )
2026-07-02 18:54:21 +01:00
e4d95e0d44
docs: add a "What's new in v2" page ( #3054 )
2026-07-02 15:01:30 +01:00
220d362112
docs: restructure into topical sections and add the four most-asked-for pages ( #3044 )
2026-07-01 21:06:04 +01:00
080f2a869d
Harden the dual-era stream loop's era-lock and rejection semantics ( #3040 )
2026-07-01 17:07:12 +01:00
48ef569f7e
Validate Mcp-Param-* headers server-side on the 2026-07-28 HTTP path (SEP-2243) ( #3033 )
2026-06-30 21:39:32 +01:00
4df609119f
Add a client extension API ( #3034 )
2026-06-30 21:31:02 +01:00
b15b1d5f07
Add a client-side response cache honoring SEP-2549 caching hints ( #3023 )
2026-06-30 11:31:06 +01:00
8d0f928e40
Pass InputRequiredResult through the MCPServer prompt and resource pipelines ( #3020 )
2026-06-29 16:50:58 +01:00
533c6a8226
Add cache_hints constructor map for SEP-2549 caching hints ( #3015 )
2026-06-29 14:11:15 +00:00
c85836a081
Drive resolver elicitation over the 2026-07-28 input_required flow ( #2986 )
...
Co-authored-by: Max Isbey <224885523+maxisbey@users.noreply.github.com >
2026-06-29 14:39:43 +01:00
24fdd909ac
docs: convert bold cross-references into links, link SEP and RFC mentions ( #3017 )
2026-06-29 11:07:26 +00:00
f664db8952
Add resolver dependency injection for MCPServer tools ( #2969 )
...
Co-authored-by: Max Isbey <224885523+maxisbey@users.noreply.github.com >
2026-06-29 11:51:46 +01:00
4b519782f1
Add a pluggable server extension API with MCP Apps ( #3003 )
...
Co-authored-by: Max Isbey <224885523+maxisbey@users.noreply.github.com >
2026-06-29 10:58:05 +01:00
24717cc8eb
feat: RFC 6570 URI templates with operator-aware security ( #2356 )
2026-06-26 20:29:17 +02:00
c0ecb70e24
Support RFC 8693 token exchange for enterprise IdP flows (SEP-990) ( #2988 )
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Co-authored-by: Max Isbey <224885523+maxisbey@users.noreply.github.com >
2026-06-26 17:57:10 +02:00
ecdf09d44f
Deprecate Server.__init__ handlers for removed capabilities ( #3002 )
2026-06-26 17:51:13 +02:00
08b62308d4
Client auto-resolves InputRequiredResult via existing callbacks (SEP-2322) ( #2998 )
2026-06-26 17:35:23 +02:00
5b2713d40c
Mirror x-mcp-header tool arguments into Mcp-Param-* request headers (SEP-2243) ( #2990 )
2026-06-26 14:36:56 +02:00
3a8da8c0c3
Fix docs/release follow-ups from the mcp-types package split ( #2977 )
2026-06-26 13:16:09 +02:00
f41a5193f3
Preserve empty issuer/resource paths on AuthSettings ( #2987 )
2026-06-26 11:41:41 +02:00
587340279e
Conformance burn-down: server-side InputRequiredResult, Mcp-Method/Name validation, x-mcp-header filter (14 scenarios → green) ( #2974 )
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2026-06-26 09:51:59 +02:00
0ee7f1b293
Split protocol types into a standalone mcp-types package ( #2973 )
2026-06-25 19:18:38 +02:00
03681ed55e
Client call_tool: input_responses/request_state retry params; InputRequiredResult via allow_input_required ( #2968 )
2026-06-25 17:37:00 +02:00
f226d00d0a
Client-side 2026-07-28 support: .discover()/.adopt() + Client(mode=); request-metadata green ( #2950 )
2026-06-25 16:09:23 +02:00
ad81ca234a
Slim ServerMiddleware to (ctx, call_next) and add OpenTelemetryMiddleware ( #2941 )
...
Co-authored-by: Max Isbey <224885523+maxisbey@users.noreply.github.com >
2026-06-22 14:46:30 +01:00
Max Isbey