Converted timing-based tests to use Go 1.25's synctest for instant,
deterministic execution with simulated time.
Moved converted tests to *_go125_test.go files. Tests using real I/O
(exec.Command, httptest) remain timing-based as they require actual
system operations.
Fixes#680
---------
Co-authored-by: i586147 <lakshana.goswami@sap.com>
This PR fixes goroutine leaks in all unit tests.
To find the leaks I integrated https://github.com/uber-go/goleak and I
suggest to keep using it to catch any future regressions.
I used the folowing script to more easily find individual tests which
were leaking goroutines:
```
for t in $(go test -run=Nothing -list=. ./mcp | grep -v ok); do go test ./mcp -run="$t" > /dev/null && echo -n . || echo -e "\nDetected leak: $t"; done
```
Provide a way for middleware to get the error from a tool call,
demonstrating that we can add this functionality without making a
breaking change.
Leave getError unexported for now; we can export it (and setError) at
any time.
For #64.
At 7s, this test was 70% of our test execution time on my computer.
Speed it up by mutating the defaultTerminateDuration for the purposes of
the test.
Also update our test workflow to use go1.25, now that it's out.
Make the process termination timeout configurable instead of using a
hardcoded 5-second delay. This allows applications to customize the
termination behavior based on their specific needs.
Fixes#322.
As described in #272, there is really no reason for transports to be
closed structs with constructors, since their state must be established
by a call to Connect. Making them open structs simplifies their APIs,
and means that all transports can be extended in the future: we don't
have to create empty Options structs just for the purpose of future
compatibility.
For now, the related constructors and options structs are simply
deprecated (with go:fix directives where possible). A future CL will
remove them prior to the v1.0.0 release.
For #272
Support stateless streamable sessions by adding a GetSessionID function
to StreamableHTTPOptions. If GetSessionID returns "", the session is
stateless, and no validation is performed. This is implemented by
providing the session a trivial initialization state.
To implement this, some parts of #232 (distributed sessions) are copied
over, since they add an API for creating an already-initialized session.
In total, the following new API is added:
- StreamableHTTPOptions.GetSessionID
- ServerSessionOptions (a new parameter to Server.Connect)
- ServerSessionState
- ClientSessionOptions (a new parameter to Client.Connect, for symmetry)
For #10
Use a read loop and incoming channel so that we can select on incoming
messages and unblock calls of ioConn.Read as soon as Close is called.
This avoids the scenario of #224, where a close of the StdioTransport
does not gracefully shut down the JSON-RPC connection.
Fixes#224
Make `Server.Run` return when the provided context is canceled.
Add tests for when the `Run` context is cancelled and also for when the
server process receives a signal.
Fixes#107.
BREAKING CHANGE
Change the API for adding tools, prompts, resources and resource
templates to a server.
The ServerXXX types are gone along with the plural Add methods
(AddTools, AddPrompts etc.)
Instead there are single Add methods (AddTool, AddPrompt).
In addition, instead of NewServerTool, there is AddTool[In, Out].
Fixes#73.
After some experience with the flattened version of Content, we see that
it can easily lead to incorrect usage and is a harder API to read.
Therefore, this CL changes back to a design similar to what we had prior
to https://go.dev/cl/672415, though opting to promote content
unmarshalling to the protocol types that use it, which leads to an
overall simpler api.
* mcp: move to 2025-06-18 schema
Add types and fields for the latest MCP schema.
The main challenge here was dealing with the presence of _meta fields
on many types, like Tool, Prompt and Resource.
- Distinguish between the _meta field of a request's params, which
includes a progress token, from the _meta field on other types,
which is simply a map.
- Redefine GetMeta to return a pointer to the map. We wanted to avoid
that, but I don't see a clean way to do so. An alternative would be
to have GetMeta return a map, and SetMeta to set it.
- Provide GetProgressToken for requests only (not notifications or other
types).
- Still to do: deal with the meta and annotation fields of ContentBlock,
which are currently duplicated for Resource and ResourceContents.
* Meta and progress token redesign
In CL 682976, Alan Donovan correctly points out that the term in the MCP
spec is 'stdio', and therefore the correct capitalization is Stdio.
Change-Id: Ib5bbe04f1a61de886298b4d0adc13aefd6aadd9c
Reviewed-on: https://go-review.googlesource.com/c/tools/+/683075
Reviewed-by: Alan Donovan <adonovan@google.com>
Auto-Submit: Robert Findley <rfindley@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Remove dependencies on the eventtest and testenv packages from
jsonrpc2_v2 and mcp packages, in preparation for forking.
Change-Id: Id0efb0c3187629f6fb1822cc853ec52acea41b0d
Reviewed-on: https://go-review.googlesource.com/c/tools/+/682696
Reviewed-by: Jonathan Amsterdam <jba@google.com>
Auto-Submit: Robert Findley <rfindley@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
The NewTool and NewPrompt constructors were unidiomatic, because they
returned a ServerTool and ServerPrompt, respectively, rather than a Tool
and Prompt. Rename to be consistent with the constructed object name.
Change-Id: Ife3f16f783368401f792660c4272e1bb5ae61638
Reviewed-on: https://go-review.googlesource.com/c/tools/+/682375
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Jonathan Amsterdam <jba@google.com>
CallToolParams.Arguments is any.
Clients can send whatever they want.
Tool authors who create their own ToolHandler (bypassing NewTool)
will receive the arguments as a map[string]any which has been
validated against the input schema.
Tool authors who call NewTool can choose the type that the arguments
unmarshal into.
There is no double-unmarshaling and no downcasting.
There is no way for tool authors to avoid the unmarshal, and no way to
avoid the validation unless the omit an input schema, which is probably
bad for LLMs. If tool authors want this optimization, we can provide
it later.
Change-Id: Ieb201e56c7fb8a23bb1a93b27e946630ec9e79ad
Reviewed-on: https://go-review.googlesource.com/c/tools/+/679595
TryBot-Bypass: Jonathan Amsterdam <jba@google.com>
Auto-Submit: Jonathan Amsterdam <jba@google.com>
Reviewed-by: Robert Findley <rfindley@google.com>
Unbreak our WASM tests by correctly marking a test as testenv.NeedsExec.
Change-Id: Ib976657e9b09acc6fc563f6fc26d6066fd64acf5
Reviewed-on: https://go-review.googlesource.com/c/tools/+/678035
Reviewed-by: Alan Donovan <adonovan@google.com>
Auto-Submit: Robert Findley <rfindley@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Make Tool APIs future-proof by pushing generics into CallToolParams, and
using CallToolParams throughout. This has several advantages:
- We no longer need the awkward CallToolOptions type, which is almost
but not quite like CallToolParams.
- NewTool no longer needs to define its own handler type: it accepts a
ToolHandler[TArgs]. This also means its signature is future-proof.
Additionally, provide a `CallTool` helper (the analog of NewTool) to
serve as a more strongly typed variant of `ClientSession.CallTool`.
+ design, protocol generation
Change-Id: I80172a25bc50734dae84a541aa4776ed9161694e
Reviewed-on: https://go-review.googlesource.com/c/tools/+/676495
Reviewed-by: Jonathan Amsterdam <jba@google.com>
Auto-Submit: Robert Findley <rfindley@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Add a logical client session type back to the SDK, to bring it closer to
the design. Also, remove 'ConnectionOptions', which is better
implemented using middleware, and reimplement logging as a
LoggingTransport middleware, which is also added to the design.
Change-Id: I908b4f837d513ffc60ae5b6171a31519cffafebc
Reviewed-on: https://go-review.googlesource.com/c/tools/+/672795
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Sam Thanawalla <samthanawalla@google.com>
Reviewed-by: Jonathan Amsterdam <jba@google.com>
CallTool takes a tool name, arguments, and an options struct.
Also, pass the params to ToolHandler.
Update the design doc accordingly.
Change-Id: I21b7995b607bea976ad708ebb6ac0716018f39cb
Reviewed-on: https://go-review.googlesource.com/c/tools/+/672596
Reviewed-by: Robert Findley <rfindley@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Use pointers for the protocol's struct types, to future-proof against
them getting large.
Change-Id: I55b204080a41c8140539697ba264e502e912e613
Reviewed-on: https://go-review.googlesource.com/c/tools/+/672575
Reviewed-by: Robert Findley <rfindley@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Now that the protocol package is merged into the mcp package, clean up
the higher level 'Content' union types, in favor of types constructors.
Change-Id: I37bedb0ff0a296eef799ba65c37ca7f94ee1dbbe
Reviewed-on: https://go-review.googlesource.com/c/tools/+/672415
Reviewed-by: Jonathan Amsterdam <jba@google.com>
TryBot-Bypass: Jonathan Amsterdam <jba@google.com>
In accordance with the updated design, merge the protocol package into
the mcp package. To do so, rename protocol.Content to WireContent and
protocol.ResourceContents to WireResource.
Also, remove some stray logging in readResource.
Change-Id: I76f61ce8d67dd3ac520ef2e1959ade0a0785a480
Reviewed-on: https://go-review.googlesource.com/c/tools/+/672375
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Jonathan Amsterdam <jba@google.com>
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>
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>
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>
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
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Jonathan Amsterdam <jba@google.com>
Auto-Submit: Robert Findley <rfindley@google.com>
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
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Jonathan Amsterdam <jba@google.com>
Add a missing CommandTransport that communicates with a sidecar process
over newline-delimited stdin/stdout, the counterpart to the existing
StdIOTransport.
Add a test using the usual TestMain trick.
Change-Id: I170ba78faf6b6d7fca7da1af11bf92e919b11ed5
Reviewed-on: https://go-review.googlesource.com/c/tools/+/668895
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Jonathan Amsterdam <jba@google.com>
