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mcp: move to 2025-06-18 schema (#8)

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* 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
This commit is contained in:
Jonathan Amsterdam 2025-06-25 09:48:33 -04:00 • committed by GitHub
commit 3da831b0c9
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1 changed files with 372 additions and 249 deletions
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mcp/protocol.go
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@ -4,6 +4,12 @@
package mcp
// Protocol types for version 2025-06-18.
// To see the schema changes from the previous version, run:
//
// prefix=https://raw.githubusercontent.com/modelcontextprotocol/modelcontextprotocol/refs/heads/main/schema
// sdiff -l <(curl $prefix/2025-03-26/schema.ts) <(curl $prefix/2025/06-18/schema.ts)
import (
"github.com/modelcontextprotocol/go-sdk/jsonschema"
)
@ -16,6 +22,13 @@ type Annotations struct {
// It can include multiple entries to indicate content useful for multiple
// audiences (e.g., `["user", "assistant"]`).
Audience []Role `json:"audience,omitempty"`
// The moment the resource was last modified, as an ISO 8601 formatted string.
//
// Should be an ISO 8601 formatted string (e.g., "2025-01-12T15:00:58Z").
//
// Examples: last activity timestamp in an open file, timestamp when the
// resource was attached, etc.
LastModified string `json:"lastModified,omitempty"`
// Describes how important this data is for operating the server.
//
// A value of 1 means "most important," and indicates that the data is
@ -27,63 +40,78 @@ type Annotations struct {
type CallToolParams struct {
// This property is reserved by the protocol to allow clients and servers to
// attach additional metadata to their responses.
Meta Meta `json:"_meta,omitempty"`
Meta `json:"_meta,omitempty"`
Arguments any `json:"arguments,omitempty"`
Name string `json:"name"`
}
func (x *CallToolParams) GetMeta() *Meta { return &x.Meta }
func (x *CallToolParams) GetProgressToken() any { return getProgressToken(x) }
func (x *CallToolParams) SetProgressToken(t any) { setProgressToken(x, t) }
type CallToolParamsFor[In any] struct {
// This property is reserved by the protocol to allow clients and servers to
// attach additional metadata to their responses.
Meta Meta `json:"_meta,omitempty"`
Meta `json:"_meta,omitempty"`
Arguments In `json:"arguments,omitempty"`
Name string `json:"name"`
}
func (x *CallToolParamsFor[In]) GetMeta() *Meta { return &x.Meta }
// The server's response to a tool call.
//
// Any errors that originate from the tool SHOULD be reported inside the result
// object, with `isError` set to true, _not_ as an MCP protocol-level error
// response. Otherwise, the LLM would not be able to see that an error occurred
// and self-correct.
//
// However, any errors in _finding_ the tool, an error indicating that the
// server does not support tool calls, or any other exceptional conditions,
// should be reported as an MCP error response.
type CallToolResult struct {
// This property is reserved by the protocol to allow clients and servers to
// attach additional metadata to their responses.
Meta Meta `json:"_meta,omitempty"`
Content []*Content `json:"content"`
Meta `json:"_meta,omitempty"`
// A list of content objects that represent the unstructured result of the tool
// call.
Content []*ContentBlock `json:"content"`
// Whether the tool call ended in an error.
//
// If not set, this is assumed to be false (the call was successful).
//
// Any errors that originate from the tool SHOULD be reported inside the result
// object, with `isError` set to true, _not_ as an MCP protocol-level error
// response. Otherwise, the LLM would not be able to see that an error occurred
// and self-correct.
//
// However, any errors in _finding_ the tool, an error indicating that the
// server does not support tool calls, or any other exceptional conditions,
// should be reported as an MCP error response.
IsError bool `json:"isError,omitempty"`
// An optional JSON object that represents the structured result of the tool
// call.
// TODO(jba,rfindley): should this be any?
StructuredContent map[string]any `json:"structuredContent,omitempty"`
}
func (x *CallToolResult) GetMeta() *Meta { return &x.Meta }
type CallToolResultFor[Out any] struct {
// This property is reserved by the protocol to allow clients and servers to
// attach additional metadata to their responses.
Meta Meta `json:"_meta,omitempty"`
Content []*Content `json:"content"`
Meta `json:"_meta,omitempty"`
// A list of content objects that represent the unstructured result of the tool
// call.
Content []*ContentBlock `json:"content"`
// Whether the tool call ended in an error.
//
// If not set, this is assumed to be false (the call was successful).
//
// Any errors that originate from the tool SHOULD be reported inside the result
// object, with `isError` set to true, not as an MCP protocol-level error
// response. Otherwise, the LLM would not be able to see that an error occurred
// and self-correct.
//
// However, any errors in finding the tool, an error indicating that the
// server does not support tool calls, or any other exceptional conditions,
// should be reported as an MCP error response.
IsError bool `json:"isError,omitempty"`
// An optional JSON object that represents the structured result of the tool
// call.
StructuredContent Out `json:"structuredContent,omitempty"`
}
func (x *CallToolResultFor[Out]) GetMeta() *Meta { return &x.Meta }
type CancelledParams struct {
// This property is reserved by the protocol to allow clients and servers to
// attach additional metadata to their responses.
Meta Meta `json:"_meta,omitempty"`
Meta `json:"_meta,omitempty"`
// An optional string describing the reason for the cancellation. This MAY be
// logged or presented to the user.
Reason string `json:"reason,omitempty"`
@ -94,7 +122,8 @@ type CancelledParams struct {
RequestID any `json:"requestId"`
}
func (x *CancelledParams) GetMeta() *Meta { return &x.Meta }
func (x *CancelledParams) GetProgressToken() any { return getProgressToken(x) }
func (x *CancelledParams) SetProgressToken(t any) { setProgressToken(x, t) }
// Capabilities a client may support. Known capabilities are defined here, in
// this schema, but this is not a closed set: any client can define its own,
@ -109,12 +138,14 @@ type ClientCapabilities struct {
} `json:"roots,omitempty"`
// Present if the client supports sampling from an LLM.
Sampling *SamplingCapabilities `json:"sampling,omitempty"`
// Present if the client supports elicitation from the server.
Elicitation *ElicitationCapabilities `json:"elicitation,omitempty"`
}
type CreateMessageParams struct {
// This property is reserved by the protocol to allow clients and servers to
// attach additional metadata to their responses.
Meta Meta `json:"_meta,omitempty"`
Meta `json:"_meta,omitempty"`
// A request to include context from one or more MCP servers (including the
// caller), to be attached to the prompt. The client MAY ignore this request.
IncludeContext string `json:"includeContext,omitempty"`
@ -135,7 +166,8 @@ type CreateMessageParams struct {
Temperature float64 `json:"temperature,omitempty"`
}
func (x *CreateMessageParams) GetMeta() *Meta { return &x.Meta }
func (x *CreateMessageParams) GetProgressToken() any { return getProgressToken(x) }
func (x *CreateMessageParams) SetProgressToken(t any) { setProgressToken(x, t) }
// The client's response to a sampling/create_message request from the server.
// The client should inform the user before returning the sampled message, to
@ -144,8 +176,8 @@ func (x *CreateMessageParams) GetMeta() *Meta { return &x.Meta }
type CreateMessageResult struct {
// This property is reserved by the protocol to allow clients and servers to
// attach additional metadata to their responses.
Meta Meta `json:"_meta,omitempty"`
Content *Content `json:"content"`
Meta `json:"_meta,omitempty"`
Content any `json:"content"`
// The name of the model that generated the message.
Model string `json:"model"`
Role Role `json:"role"`
@ -153,36 +185,33 @@ type CreateMessageResult struct {
StopReason string `json:"stopReason,omitempty"`
}
func (x *CreateMessageResult) GetMeta() *Meta { return &x.Meta }
type GetPromptParams struct {
// This property is reserved by the protocol to allow clients and servers to
// attach additional metadata to their responses.
Meta Meta `json:"_meta,omitempty"`
Meta `json:"_meta,omitempty"`
// Arguments to use for templating the prompt.
Arguments map[string]string `json:"arguments,omitempty"`
// The name of the prompt or prompt template.
Name string `json:"name"`
}
func (x *GetPromptParams) GetMeta() *Meta { return &x.Meta }
func (x *GetPromptParams) GetProgressToken() any { return getProgressToken(x) }
func (x *GetPromptParams) SetProgressToken(t any) { setProgressToken(x, t) }
// The server's response to a prompts/get request from the client.
type GetPromptResult struct {
// This property is reserved by the protocol to allow clients and servers to
// attach additional metadata to their responses.
Meta Meta `json:"_meta,omitempty"`
Meta `json:"_meta,omitempty"`
// An optional description for the prompt.
Description string `json:"description,omitempty"`
Messages []*PromptMessage `json:"messages"`
}
func (x *GetPromptResult) GetMeta() *Meta { return &x.Meta }
type InitializeParams struct {
// This property is reserved by the protocol to allow clients and servers to
// attach additional metadata to their responses.
Meta Meta `json:"_meta,omitempty"`
Meta `json:"_meta,omitempty"`
Capabilities *ClientCapabilities `json:"capabilities"`
ClientInfo *implementation `json:"clientInfo"`
// The latest version of the Model Context Protocol that the client supports.
@ -190,14 +219,15 @@ type InitializeParams struct {
ProtocolVersion string `json:"protocolVersion"`
}
func (x *InitializeParams) GetMeta() *Meta { return &x.Meta }
func (x *InitializeParams) GetProgressToken() any { return getProgressToken(x) }
func (x *InitializeParams) SetProgressToken(t any) { setProgressToken(x, t) }
// After receiving an initialize request from the client, the server sends this
// response.
type InitializeResult struct {
// This property is reserved by the protocol to allow clients and servers to
// attach additional metadata to their responses.
Meta Meta `json:"_meta,omitempty"`
Meta `json:"_meta,omitempty"`
Capabilities *serverCapabilities `json:"capabilities"`
// Instructions describing how to use the server and its features.
//
@ -212,101 +242,101 @@ type InitializeResult struct {
ServerInfo *implementation `json:"serverInfo"`
}
func (x *InitializeResult) GetMeta() *Meta { return &x.Meta }
type InitializedParams struct {
// This property is reserved by the protocol to allow clients and servers to
// attach additional metadata to their responses.
Meta Meta `json:"_meta,omitempty"`
Meta `json:"_meta,omitempty"`
}
func (x *InitializedParams) GetMeta() *Meta { return &x.Meta }
func (x *InitializedParams) GetProgressToken() any { return getProgressToken(x) }
func (x *InitializedParams) SetProgressToken(t any) { setProgressToken(x, t) }
type ListPromptsParams struct {
// This property is reserved by the protocol to allow clients and servers to
// attach additional metadata to their responses.
Meta Meta `json:"_meta,omitempty"`
Meta `json:"_meta,omitempty"`
// An opaque token representing the current pagination position. If provided,
// the server should return results starting after this cursor.
Cursor string `json:"cursor,omitempty"`
}
func (x *ListPromptsParams) GetMeta() *Meta { return &x.Meta }
func (x *ListPromptsParams) cursorPtr() *string { return &x.Cursor }
func (x *ListPromptsParams) GetProgressToken() any { return getProgressToken(x) }
func (x *ListPromptsParams) SetProgressToken(t any) { setProgressToken(x, t) }
func (x *ListPromptsParams) cursorPtr() *string { return &x.Cursor }
// The server's response to a prompts/list request from the client.
type ListPromptsResult struct {
// This property is reserved by the protocol to allow clients and servers to
// attach additional metadata to their responses.
Meta Meta `json:"_meta,omitempty"`
Meta `json:"_meta,omitempty"`
// An opaque token representing the pagination position after the last returned
// result. If present, there may be more results available.
NextCursor string `json:"nextCursor,omitempty"`
Prompts []*Prompt `json:"prompts"`
}
func (x *ListPromptsResult) GetMeta() *Meta { return &x.Meta }
func (x *ListPromptsResult) nextCursorPtr() *string { return &x.NextCursor }
type ListResourceTemplatesParams struct {
// This property is reserved by the protocol to allow clients and servers to
// attach additional metadata to their responses.
Meta Meta `json:"_meta,omitempty"`
Meta `json:"_meta,omitempty"`
// An opaque token representing the current pagination position. If provided,
// the server should return results starting after this cursor.
Cursor string `json:"cursor,omitempty"`
}
func (x *ListResourceTemplatesParams) GetMeta() *Meta { return &x.Meta }
func (x *ListResourceTemplatesParams) cursorPtr() *string { return &x.Cursor }
func (x *ListResourceTemplatesParams) GetProgressToken() any { return getProgressToken(x) }
func (x *ListResourceTemplatesParams) SetProgressToken(t any) { setProgressToken(x, t) }
func (x *ListResourceTemplatesParams) cursorPtr() *string { return &x.Cursor }
// The server's response to a resources/templates/list request from the client.
type ListResourceTemplatesResult struct {
// This property is reserved by the protocol to allow clients and servers to
// attach additional metadata to their responses.
Meta Meta `json:"_meta,omitempty"`
Meta `json:"_meta,omitempty"`
// An opaque token representing the pagination position after the last returned
// result. If present, there may be more results available.
NextCursor string `json:"nextCursor,omitempty"`
ResourceTemplates []*ResourceTemplate `json:"resourceTemplates"`
}
func (x *ListResourceTemplatesResult) GetMeta() *Meta { return &x.Meta }
func (x *ListResourceTemplatesResult) nextCursorPtr() *string { return &x.NextCursor }
type ListResourcesParams struct {
// This property is reserved by the protocol to allow clients and servers to
// attach additional metadata to their responses.
Meta Meta `json:"_meta,omitempty"`
Meta `json:"_meta,omitempty"`
// An opaque token representing the current pagination position. If provided,
// the server should return results starting after this cursor.
Cursor string `json:"cursor,omitempty"`
}
func (x *ListResourcesParams) GetMeta() *Meta { return &x.Meta }
func (x *ListResourcesParams) cursorPtr() *string { return &x.Cursor }
func (x *ListResourcesParams) GetProgressToken() any { return getProgressToken(x) }
func (x *ListResourcesParams) SetProgressToken(t any) { setProgressToken(x, t) }
func (x *ListResourcesParams) cursorPtr() *string { return &x.Cursor }
// The server's response to a resources/list request from the client.
type ListResourcesResult struct {
// This property is reserved by the protocol to allow clients and servers to
// attach additional metadata to their responses.
Meta Meta `json:"_meta,omitempty"`
Meta `json:"_meta,omitempty"`
// An opaque token representing the pagination position after the last returned
// result. If present, there may be more results available.
NextCursor string `json:"nextCursor,omitempty"`
Resources []*Resource `json:"resources"`
}
func (x *ListResourcesResult) GetMeta() *Meta { return &x.Meta }
func (x *ListResourcesResult) nextCursorPtr() *string { return &x.NextCursor }
type ListRootsParams struct {
// This property is reserved by the protocol to allow clients and servers to
// attach additional metadata to their responses.
Meta Meta `json:"_meta,omitempty"`
Meta `json:"_meta,omitempty"`
}
func (x *ListRootsParams) GetMeta() *Meta { return &x.Meta }
func (x *ListRootsParams) GetProgressToken() any { return getProgressToken(x) }
func (x *ListRootsParams) SetProgressToken(t any) { setProgressToken(x, t) }
// The client's response to a roots/list request from the server. This result
// contains an array of Root objects, each representing a root directory or file
@ -314,36 +344,34 @@ func (x *ListRootsParams) GetMeta() *Meta { return &x.Meta }
type ListRootsResult struct {
// This property is reserved by the protocol to allow clients and servers to
// attach additional metadata to their responses.
Meta Meta `json:"_meta,omitempty"`
Meta `json:"_meta,omitempty"`
Roots []*Root `json:"roots"`
}
func (x *ListRootsResult) GetMeta() *Meta { return &x.Meta }
type ListToolsParams struct {
// This property is reserved by the protocol to allow clients and servers to
// attach additional metadata to their responses.
Meta Meta `json:"_meta,omitempty"`
Meta `json:"_meta,omitempty"`
// An opaque token representing the current pagination position. If provided,
// the server should return results starting after this cursor.
Cursor string `json:"cursor,omitempty"`
}
func (x *ListToolsParams) GetMeta() *Meta { return &x.Meta }
func (x *ListToolsParams) cursorPtr() *string { return &x.Cursor }
func (x *ListToolsParams) GetProgressToken() any { return getProgressToken(x) }
func (x *ListToolsParams) SetProgressToken(t any) { setProgressToken(x, t) }
func (x *ListToolsParams) cursorPtr() *string { return &x.Cursor }
// The server's response to a tools/list request from the client.
type ListToolsResult struct {
// This property is reserved by the protocol to allow clients and servers to
// attach additional metadata to their responses.
Meta Meta `json:"_meta,omitempty"`
Meta `json:"_meta,omitempty"`
// An opaque token representing the pagination position after the last returned
// result. If present, there may be more results available.
NextCursor string `json:"nextCursor,omitempty"`
Tools []*Tool `json:"tools"`
}
func (x *ListToolsResult) GetMeta() *Meta { return &x.Meta }
func (x *ListToolsResult) nextCursorPtr() *string { return &x.NextCursor }
// The severity of a log message.
@ -355,7 +383,7 @@ type LoggingLevel string
type LoggingMessageParams struct {
// This property is reserved by the protocol to allow clients and servers to
// attach additional metadata to their responses.
Meta Meta `json:"_meta,omitempty"`
Meta `json:"_meta,omitempty"`
// The data to be logged, such as a string message or an object. Any JSON
// serializable type is allowed here.
Data any `json:"data"`
@ -365,7 +393,8 @@ type LoggingMessageParams struct {
Logger string `json:"logger,omitempty"`
}
func (x *LoggingMessageParams) GetMeta() *Meta { return &x.Meta }
func (x *LoggingMessageParams) GetProgressToken() any { return getProgressToken(x) }
func (x *LoggingMessageParams) SetProgressToken(t any) { setProgressToken(x, t) }
// Hints to use for model selection.
//
@ -422,15 +451,16 @@ type ModelPreferences struct {
type PingParams struct {
// This property is reserved by the protocol to allow clients and servers to
// attach additional metadata to their responses.
Meta Meta `json:"_meta,omitempty"`
Meta `json:"_meta,omitempty"`
}
func (x *PingParams) GetMeta() *Meta { return &x.Meta }
func (x *PingParams) GetProgressToken() any { return getProgressToken(x) }
func (x *PingParams) SetProgressToken(t any) { setProgressToken(x, t) }
type ProgressNotificationParams struct {
// This property is reserved by the protocol to allow clients and servers to
// attach additional metadata to their responses.
Meta Meta `json:"_meta,omitempty"`
Meta `json:"_meta,omitempty"`
// An optional message describing the current progress.
Message string `json:"message,omitempty"`
// The progress thus far. This should increase every time progress is made, even
@ -443,24 +473,33 @@ type ProgressNotificationParams struct {
Total float64 `json:"total,omitempty"`
}
func (x *ProgressNotificationParams) GetMeta() *Meta { return &x.Meta }
// A prompt or prompt template that the server offers.
type Prompt struct {
// See [specification/2025-06-18/basic/index#general-fields] for notes on _meta
// usage.
Meta `json:"_meta,omitempty"`
// A list of arguments to use for templating the prompt.
Arguments []*PromptArgument `json:"arguments,omitempty"`
// An optional description of what this prompt provides
Description string `json:"description,omitempty"`
// The name of the prompt or prompt template.
// Intended for programmatic or logical use, but used as a display name in past
// specs or fallback (if title isn't present).
Name string `json:"name"`
// Intended for UI and end-user contexts — optimized to be human-readable and
// easily understood, even by those unfamiliar with domain-specific terminology.
Title string `json:"title,omitempty"`
}
// Describes an argument that a prompt can accept.
type PromptArgument struct {
// Intended for programmatic or logical use, but used as a display name in past
// specs or fallback (if title isn't present).
Name string `json:"name"`
// Intended for UI and end-user contexts — optimized to be human-readable and
// easily understood, even by those unfamiliar with domain-specific terminology.
Title string `json:"title,omitempty"`
// A human-readable description of the argument.
Description string `json:"description,omitempty"`
// The name of the argument.
Name string `json:"name"`
// Whether this argument must be provided.
Required bool `json:"required,omitempty"`
}
@ -468,43 +507,46 @@ type PromptArgument struct {
type PromptListChangedParams struct {
// This property is reserved by the protocol to allow clients and servers to
// attach additional metadata to their responses.
Meta Meta `json:"_meta,omitempty"`
Meta `json:"_meta,omitempty"`
}
func (x *PromptListChangedParams) GetMeta() *Meta { return &x.Meta }
func (x *PromptListChangedParams) GetProgressToken() any { return getProgressToken(x) }
func (x *PromptListChangedParams) SetProgressToken(t any) { setProgressToken(x, t) }
// Describes a message returned as part of a prompt.
//
// This is similar to `SamplingMessage`, but also supports the embedding of
// resources from the MCP server.
type PromptMessage struct {
Content *Content `json:"content"`
Role Role `json:"role"`
Content *ContentBlock `json:"content"`
Role Role `json:"role"`
}
type ReadResourceParams struct {
// This property is reserved by the protocol to allow clients and servers to
// attach additional metadata to their responses.
Meta Meta `json:"_meta,omitempty"`
Meta `json:"_meta,omitempty"`
// The URI of the resource to read. The URI can use any protocol; it is up to
// the server how to interpret it.
URI string `json:"uri"`
}
func (x *ReadResourceParams) GetMeta() *Meta { return &x.Meta }
func (x *ReadResourceParams) GetProgressToken() any { return getProgressToken(x) }
func (x *ReadResourceParams) SetProgressToken(t any) { setProgressToken(x, t) }
// The server's response to a resources/read request from the client.
type ReadResourceResult struct {
// This property is reserved by the protocol to allow clients and servers to
// attach additional metadata to their responses.
Meta Meta `json:"_meta,omitempty"`
Meta `json:"_meta,omitempty"`
Contents []*ResourceContents `json:"contents"`
}
func (x *ReadResourceResult) GetMeta() *Meta { return &x.Meta }
// A known resource that the server is capable of reading.
type Resource struct {
// See [specification/2025-06-18/basic/index#general-fields] for notes on _meta
// usage.
Meta `json:"_meta,omitempty"`
// Optional annotations for the client.
Annotations *Annotations `json:"annotations,omitempty"`
// A description of what this resource represents.
@ -514,9 +556,8 @@ type Resource struct {
Description string `json:"description,omitempty"`
// The MIME type of this resource, if known.
MIMEType string `json:"mimeType,omitempty"`
// A human-readable name for this resource.
//
// This can be used by clients to populate UI elements.
// Intended for programmatic or logical use, but used as a display name in past
// specs or fallback (if title isn't present).
Name string `json:"name"`
// The size of the raw resource content, in bytes (i.e., before base64 encoding
// or any tokenization), if known.
@ -524,6 +565,13 @@ type Resource struct {
// This can be used by Hosts to display file sizes and estimate context window
// usage.
Size int64 `json:"size,omitempty"`
// Intended for UI and end-user contexts — optimized to be human-readable and
// easily understood, even by those unfamiliar with domain-specific terminology.
//
// If not provided, the name should be used for display (except for Tool, where
// `annotations.title` should be given precedence over using `name`, if
// present).
Title string `json:"title,omitempty"`
// The URI of this resource.
URI string `json:"uri"`
}
@ -531,13 +579,17 @@ type Resource struct {
type ResourceListChangedParams struct {
// This property is reserved by the protocol to allow clients and servers to
// attach additional metadata to their responses.
Meta Meta `json:"_meta,omitempty"`
Meta `json:"_meta,omitempty"`
}
func (x *ResourceListChangedParams) GetMeta() *Meta { return &x.Meta }
func (x *ResourceListChangedParams) GetProgressToken() any { return getProgressToken(x) }
func (x *ResourceListChangedParams) SetProgressToken(t any) { setProgressToken(x, t) }
// A template description for resources available on the server.
type ResourceTemplate struct {
// See [specification/2025-06-18/basic/index#general-fields] for notes on _meta
// usage.
Meta `json:"_meta,omitempty"`
// Optional annotations for the client.
Annotations *Annotations `json:"annotations,omitempty"`
// A description of what this template is for.
@ -548,10 +600,16 @@ type ResourceTemplate struct {
// The MIME type for all resources that match this template. This should only be
// included if all resources matching this template have the same type.
MIMEType string `json:"mimeType,omitempty"`
// A human-readable name for the type of resource this template refers to.
//
// This can be used by clients to populate UI elements.
// Intended for programmatic or logical use, but used as a display name in past
// specs or fallback (if title isn't present).
Name string `json:"name"`
// Intended for UI and end-user contexts — optimized to be human-readable and
// easily understood, even by those unfamiliar with domain-specific terminology.
//
// If not provided, the name should be used for display (except for Tool, where
// `annotations.title` should be given precedence over using `name`, if
// present).
Title string `json:"title,omitempty"`
// A URI template (according to RFC 6570) that can be used to construct resource
// URIs.
URITemplate string `json:"uriTemplate"`
@ -562,6 +620,9 @@ type Role string
// Represents a root directory or file that the server can operate on.
type Root struct {
// See [specification/2025-06-18/basic/index#general-fields] for notes on _meta
// usage.
Meta `json:"_meta,omitempty"`
// An optional name for the root. This can be used to provide a human-readable
// identifier for the root, which may be useful for display purposes or for
// referencing the root in other parts of the application.
@ -575,35 +636,45 @@ type Root struct {
type RootsListChangedParams struct {
// This property is reserved by the protocol to allow clients and servers to
// attach additional metadata to their responses.
Meta Meta `json:"_meta,omitempty"`
Meta `json:"_meta,omitempty"`
}
func (x *RootsListChangedParams) GetMeta() *Meta { return &x.Meta }
func (x *RootsListChangedParams) GetProgressToken() any { return getProgressToken(x) }
func (x *RootsListChangedParams) SetProgressToken(t any) { setProgressToken(x, t) }
// Present if the client supports sampling from an LLM.
// SamplingCapabilities describes the capabilities for sampling.
type SamplingCapabilities struct{}
// ElicitationCapabilities describes the capabilities for elicitation.
type ElicitationCapabilities struct{}
// Describes a message issued to or received from an LLM API.
type SamplingMessage struct {
Content *Content `json:"content"`
Role Role `json:"role"`
Content any `json:"content"`
Role Role `json:"role"`
}
type SetLevelParams struct {
// This property is reserved by the protocol to allow clients and servers to
// attach additional metadata to their responses.
Meta Meta `json:"_meta,omitempty"`
Meta `json:"_meta,omitempty"`
// The level of logging that the client wants to receive from the server. The
// server should send all logs at this level and higher (i.e., more severe) to
// the client as notifications/message.
Level LoggingLevel `json:"level"`
}
func (x *SetLevelParams) GetMeta() *Meta { return &x.Meta }
func (x *SetLevelParams) GetProgressToken() any { return getProgressToken(x) }
func (x *SetLevelParams) SetProgressToken(t any) { setProgressToken(x, t) }
// Definition for a tool the client can call.
type Tool struct {
// See [specification/2025-06-18/basic/index#general-fields] for notes on _meta
// usage.
Meta `json:"_meta,omitempty"`
// Optional additional tool information.
//
// Display name precedence order is: title, annotations.title, then name.
Annotations *ToolAnnotations `json:"annotations,omitempty"`
// A human-readable description of the tool.
//
@ -612,8 +683,17 @@ type Tool struct {
Description string `json:"description,omitempty"`
// A JSON Schema object defining the expected parameters for the tool.
InputSchema *jsonschema.Schema `json:"inputSchema"`
// The name of the tool.
// Intended for programmatic or logical use, but used as a display name in past
// specs or fallback (if title isn't present).
Name string `json:"name"`
// An optional JSON Schema object defining the structure of the tool's output
// returned in the structuredContent field of a CallToolResult.
OutputSchema *jsonschema.Schema `json:"outputSchema,omitempty"`
// Intended for UI and end-user contexts — optimized to be human-readable and
// easily understood, even by those unfamiliar with domain-specific terminology.
// If not provided, Annotations.Title should be used for display if present,
// otherwise Name.
Title string `json:"title,omitempty"`
}
// Additional properties describing a Tool to clients.
@ -656,14 +736,25 @@ type ToolAnnotations struct {
type ToolListChangedParams struct {
// This property is reserved by the protocol to allow clients and servers to
// attach additional metadata to their responses.
Meta Meta `json:"_meta,omitempty"`
Meta `json:"_meta,omitempty"`
}
func (x *ToolListChangedParams) GetMeta() *Meta { return &x.Meta }
func (x *ToolListChangedParams) GetProgressToken() any { return getProgressToken(x) }
func (x *ToolListChangedParams) SetProgressToken(t any) { setProgressToken(x, t) }
// Describes the name and version of an MCP implementation.
// TODO(jba): add CompleteRequest and related types.
// TODO(jba): add ElicitRequest and related types.
// Describes the name and version of an MCP implementation, with an optional
// title for UI representation.
type implementation struct {
Name string `json:"name"`
// Intended for programmatic or logical use, but used as a display name in past
// specs or fallback (if title isn't present).
Name string `json:"name"`
// Intended for UI and end-user contexts — optimized to be human-readable and
// easily understood, even by those unfamiliar with domain-specific terminology.
Title string `json:"title,omitempty"`
Version string `json:"version"`
}
@ -713,6 +804,7 @@ const (
notificationCancelled = "notifications/cancelled"
methodComplete = "completion/complete"
methodCreateMessage = "sampling/createMessage"
methodElicit = "elicitation/create"
methodGetPrompt = "prompts/get"
methodInitialize = "initialize"
notificationInitialized = "notifications/initialized"