Commit graph go-sdk/mcp/mcp_test.go
Author SHA1 Message Date
Rob Findley
347a1a0078 internal/mcp: rename ClientConnection to ServerConnection
It's too confusing that you send server requests through the Client, and
send client requests through the ClientConnection. Rename
ClientConnection to ServerConnection, so that the types on the
server side of the control diagram start with 'Server'.

Change-Id: Idfd27af464a9296a2341cd23b2075cd9d0eb6b45
Reviewed-on: https://go-review.googlesource.com/c/tools/+/670538
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Auto-Submit: Robert Findley <rfindley@google.com>
Reviewed-by: Jonathan Amsterdam <jba@google.com>
2025-05-07 10:17:38 -07:00
Jonathan Amsterdam
e0e304e51e internal/mcp: rename Make* to New*
Change-Id: I8d3d2ca125b7c24dd265937c4fe910ea823ab811
Reviewed-on: https://go-review.googlesource.com/c/tools/+/670537
Reviewed-by: Robert Findley <rfindley@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
2025-05-07 09:32:55 -07:00
Jonathan Amsterdam
f8098af1c5 internal/mcp: NewClient takes Transport
Pass the client Transport to NewClient instead of Connect.
Combine the ConnectionOptions with the ClientOptions.

Change-Id: I3acd6cf6d5bf46666742f2a73e2acaef2057ea77
Reviewed-on: https://go-review.googlesource.com/c/tools/+/670215
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Robert Findley <rfindley@google.com>
2025-05-06 12:19:25 -07:00
Rob Findley
8efb54691d internal/mcp/protocol: move out of mcp/internal, as it's used in the API
The generated protocol package is part of the SDK API, so it shouldn't
be internal.

Change-Id: I5306af48019b1599707b939b348eb6ae4f766ca9
Reviewed-on: https://go-review.googlesource.com/c/tools/+/670356
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Jonathan Amsterdam <jba@google.com>
2025-05-06 10:18:38 -07:00
Jonathan Amsterdam
15e0c9ef02 internal/mcp: move jsonschema out of mcp/internal
The jsonschema package is part of of the API of the mcp package,
so it should not be internal.

Change-Id: I9520797837329fc2cda09c2f46ec4d48d031b9d3
Reviewed-on: https://go-review.googlesource.com/c/tools/+/669996
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Robert Findley <rfindley@google.com>
2025-05-05 13:17:44 -07:00
Jonathan Amsterdam
3d33fafc5d jsonschema: pre-compile regexps
This is the first CL that deals with the process of preparing a schema for validation.

Perform some basic checks on the scheme. Along the way, compile regexps and store
them in the schema for use during validation.

Change-Id: I0e5e6ce28656dcecb6d2d4b2fdc98998fa05b6f1
Reviewed-on: https://go-review.googlesource.com/c/tools/+/669696
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Alan Donovan <adonovan@google.com>
2025-05-05 12:29:58 -07:00
Jonathan Amsterdam
7a76f3502a mcp: remove ServerConnection
Remove ServerConnection.
- It's not in typescript or mcpgo APIs.
- Amortizing a client over multiple servers doesn't have any value.

Change-Id: I725b42569733d6836864d96b16898a10ae91e570
Reviewed-on: https://go-review.googlesource.com/c/tools/+/669575
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Robert Findley <rfindley@google.com>
2025-05-02 13:30:38 -07:00
Rob Findley
bf608eeeae internal/mcp: clean up handling of content
Add support for all content types, and formalize the conversion of
content to and from the wire format (as a discriminated union).

Change-Id: I93678ce98c02176a524d2c82425fb1267ad68bf0
Reviewed-on: https://go-review.googlesource.com/c/tools/+/669135
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2025-05-01 19:15:30 -07:00
Rob Findley
af4d138732 internal/mcp: support prompts
Add support for 'prompts/list' and 'prompts/get', and registering
prompts on the server using AddPrompts. Add a 'MakePrompt' helper to
construct prompts from a prompt handler using reflection.

Change-Id: I479cb9c9b99313cca99640c1f5ea1939363759e6
Reviewed-on: https://go-review.googlesource.com/c/tools/+/669015
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Reviewed-by: Jonathan Amsterdam <jba@google.com>
2025-05-01 18:43:44 -07:00
Rob Findley
e082a340be internal/mcp: add tool and schema options
Implement variadic options for building tools and schemas, to allow
easier customization of tool input schemas.

Also, make fields required, unless they are marked as "omitempty".

Change-Id: I7a29258fae3ec5e7ea4906ed30ed6750979de962
Reviewed-on: https://go-review.googlesource.com/c/tools/+/668955
Reviewed-by: Jonathan Amsterdam <jba@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
2025-05-01 18:41:25 -07:00
Jonathan Amsterdam
3434e57007 internal/mcp/internal/jsonschema: schema definition
The first of several CLs providing JSON Schema validation.

Replace the existing Schema type with one that has all the keywords
of the most current version of the JSON Schema spec, called 2020-12.

The 2020-12 spec can be represented type-safely in Go with one exception:
the "type" keyword can be either a string or a []string. To handle this
safely, both Type and Types fields are defined. Custom
JSONMarshal/Unmarshal methods handle the conversion. We need the
unmarshal anyway because "true" and "false" are valid schemas.

Unfortunately, the MCP spec uses the older "draft7" version of JSON
Schema, but the two are close enough for code generation to work.
I confirmed that the protocol generator produces the identical output.

Change-Id: I44f6ea2f3a3f8498979946f69dfb7f50afa1acad
Reviewed-on: https://go-review.googlesource.com/c/tools/+/667855
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Reviewed-by: Alan Donovan <adonovan@google.com>
2025-04-25 08:33:53 -07:00
Rob Findley
14b18b2645 internal/mcp: implement cancellation
Use the existing jsonrpc2 preemption mechanism to implement MCP
cancellation.

This was mostly straightforward, except where I got confused about ID
unmarshaling. Leave a note about using omitempty when it is available.

Change-Id: I13e073f08c5d5c2cc78d882da4e6ff47f09fb340
Reviewed-on: https://go-review.googlesource.com/c/tools/+/667578
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Reviewed-by: Jonathan Amsterdam <jba@google.com>
2025-04-23 19:15:39 -07:00
Rob Findley
fe938f6eb7 internal/mcp: implement ping, and test request interleaving
Also validate that requests observe the lifecycle rules defined in the
spec.

Change-Id: I302282f81e053e76926e0bb295f7dbf8d526f02d
Reviewed-on: https://go-review.googlesource.com/c/tools/+/667575
Reviewed-by: Jonathan Amsterdam <jba@google.com>
Commit-Queue: Robert Findley <rfindley@google.com>
Auto-Submit: Robert Findley <rfindley@google.com>
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2025-04-23 19:15:29 -07:00
Rob Findley
ef446f82d7 internal/mcp: implement HTTP SSE transport
Add support for SSE transport, as defined by version 2024-11-05 and
2025-03-26 of the MCP spec.

In order to achieve this, the jsonrpc2 stream must be abstracted so that
we can implement it across multiple HTTP requests. This required some
refactoring of the jsonrpc2_v2 package, so that we can avoid the
Dialer/Binder interfaces and construct the Connection directly from its
constituent primitives.

Change-Id: Id627b5b5a474d92f2c613cfad904d14611e7c768
Reviewed-on: https://go-review.googlesource.com/c/tools/+/667475
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Jonathan Amsterdam <jba@google.com>
2025-04-23 19:15:20 -07:00
Rob Findley
1204b93a85 internal/mcp: add batching support
Update the jsonrpc2 MCP framer to support both incoming and outgoing
batches. In order to achieve this, we must correlate the framed Reader
and Writer, which is not explicitly supported by the jsonrpc2 API, but
does work. A note is left to revisit the Framer interface.

Change-Id: If060cb5822da067833db20d58f5f112a0528da91
Reviewed-on: https://go-review.googlesource.com/c/tools/+/667295
Reviewed-by: Jonathan Amsterdam <jba@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
2025-04-22 14:39:09 -07:00
Rob Findley
34cc770852 internal/mcp: an MCP SDK prototype
This CL contains an minimal prototype of an MCP SDK, using the
"new" jsonrpc2_v2 package (similar to x/exp/jsonrpc2).

Much is still yet to do, but this initial version addressed the
following aspects:

- Support for newline delimited JSONRPC2 framing, and message logging.
- A generated protocol package, containing type definitions to be used
  in transport.
- A minimal jsonschema package to be used for both reading the MCP spec,
  and for serving Tool input schemas.
- A transport abstraction, and two transport implementations: stdio, and
  local (for testing).
- Client and Server types, to be configured with features and then
  connected using their Connect methods, which return (respectively) a
  ServerConnection and ClientConnection object.
- A minimal binding API for tools.

A catalog of things not yet done is in doc.go, but we should review this
CL eagerly, as it contains the fundamental building blocks of an
eventual SDK.

It is the intention that this package is more-or-less standalone, as it
may eventually be carved out into a separate repository. As such, its
only dependency within x/tools is jsonrpc2_v2, and the only change
required to that package is to expose a callback when the connection is
closed.

Change-Id: Ib66018961014f85a8884d56ab721d5642c98443c
Reviewed-on: https://go-review.googlesource.com/c/tools/+/667036
Reviewed-by: Jonathan Amsterdam <jba@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
2025-04-22 14:37:47 -07:00