Package io.modelcontextprotocol.spec

Class McpSchema

java.lang.Object

io.modelcontextprotocol.spec.McpSchema

public final class McpSchema
extends Object

Based on the JSON-RPC 2.0 specification and the Model Context Protocol Schema.

Author:

Christian Tzolov, Luca Chang, Surbhi Bansal, Anurag Pant, Dariusz Jędrzejczyk

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static interface	McpSchema.Annotated	Base for objects that include optional annotations for the client.
static final record	McpSchema.Annotations	Optional annotations for the client.
static final record	McpSchema.AudioContent	Audio provided to or from an LLM.
static final record	McpSchema.BlobResourceContents	Binary contents of a resource.
static final record	McpSchema.BooleanSchema	Schema for a boolean field in a form-based elicitation request.
static final record	McpSchema.CallToolRequest	Used by the client to call a tool provided by the server.
static final record	McpSchema.CallToolResult	The server's response to a tools/call request from the client.
static final record	McpSchema.ClientCapabilities	Capabilities a client may support.
static interface	McpSchema.CompleteReference	A reference to a prompt or resource that can be used as input for completion requests.
static final record	McpSchema.CompleteRequest	A request from the client to the server, to ask for completion options.
static final record	McpSchema.CompleteResult	The server's response to a completion/complete request.
static interface	McpSchema.Content	A polymorphic content value that can appear in messages and tool results.
static final record	McpSchema.CreateMessageRequest	A request from the server to sample an LLM via the client.
static final record	McpSchema.CreateMessageResult	The client's response to a sampling/create_message request from the server.
static final record	McpSchema.ElicitationCompleteNotification	A notification from the server to the client indicating that an out-of-band URL elicitation interaction has completed.
static final record	McpSchema.ElicitFormRequest	A request from the server to elicit additional information from the user via the client, using form mode.
static interface	McpSchema.ElicitRequest	A request from the server to elicit additional information from the user, either through the client or out-of-band.
static final record	McpSchema.ElicitResult	The client's response to an elicitation request.
static final record	McpSchema.ElicitUrlRequest	A request from the server to elicit additional information from the user out of band, using url mode.
static final record	McpSchema.EmbeddedResource	The contents of a resource, embedded into a prompt or tool call result.
static final record	McpSchema.EnumSchemaOption	An option in a titled enum schema, with a machine-readable value and a human-readable display label.
static final class	McpSchema.ErrorCodes	Standard error codes used in MCP JSON-RPC responses.
static final record	McpSchema.GetPromptRequest	Used by the client to get a prompt provided by the server.
static final record	McpSchema.GetPromptResult	The server's response to a prompts/get request from the client.
static final record	McpSchema.Icon	Represents an icon that can be displayed in a user interface.
static interface	McpSchema.Identifier	Base interface with name (identifier) and title (display name) properties.
static final record	McpSchema.ImageContent	An image provided to or from an LLM.
static final record	McpSchema.Implementation	Describes the name and version of an MCP implementation, with an optional title for UI representation.
static final record	McpSchema.InitializeRequest	This request is sent from the client to the server when it first connects, asking it to begin initialization.
static final record	McpSchema.InitializeResult	After receiving an initialize request from the client, the server sends this response.
static interface	McpSchema.JSONRPCMessage
static final record	McpSchema.JSONRPCNotification	A notification which does not expect a response.
static final record	McpSchema.JSONRPCRequest	A request that expects a response.
static final record	McpSchema.JSONRPCResponse	A response to a request (successful, or error).
static final record	McpSchema.JsonSchema	Deprecated. use Map instead.
static final record	McpSchema.LegacyTitledEnumSchema	Deprecated. Use McpSchema.TitledSingleSelectEnumSchema instead
static final record	McpSchema.ListPromptsResult	The server's response to a prompts/list request from the client.
static final record	McpSchema.ListResourcesResult	The server's response to a resources/list request from the client.
static final record	McpSchema.ListResourceTemplatesResult	The server's response to a resources/templates/list request from the client.
static final record	McpSchema.ListRootsResult	The client's response to a roots/list request from the server.
static final record	McpSchema.ListToolsResult	The server's response to a tools/list request from the client.
static enum	McpSchema.LoggingLevel	Severity levels for MCP log messages, ordered from least to most severe.
static final record	McpSchema.LoggingMessageNotification	The Model Context Protocol (MCP) provides a standardized way for servers to send structured log messages to clients.
static interface	McpSchema.Meta	Base interface for MCP objects that include optional metadata in the `_meta` field.
static final record	McpSchema.ModelHint	Hints to use for model selection.
static final record	McpSchema.ModelPreferences	The server's preferences for model selection, requested of the client during sampling.
static interface	McpSchema.Notification
static final record	McpSchema.NumberSchema	Schema for a numeric field in a form-based elicitation request, supporting both "number" (floating-point) and "integer" types.
static final record	McpSchema.PaginatedRequest	A request that supports pagination using cursors.
static final record	McpSchema.PaginatedResult	An opaque token representing the pagination position after the last returned result.
static final record	McpSchema.ProgressNotification	The Model Context Protocol (MCP) supports optional progress tracking for long-running operations through notification messages.
static final record	McpSchema.Prompt	A prompt or prompt template that the server offers.
static final record	McpSchema.PromptArgument	Describes an argument that a prompt can accept.
static final record	McpSchema.PromptMessage	Describes a message returned as part of a prompt.
static final record	McpSchema.PromptReference	Identifies a prompt for completion requests.
static final record	McpSchema.ReadResourceRequest	Sent from the client to the server, to read a specific resource URI.
static final record	McpSchema.ReadResourceResult	The server's response to a resources/read request from the client.
static interface	McpSchema.Request
static final record	McpSchema.Resource	A known resource that the server is capable of reading.
static interface	McpSchema.ResourceContent	A common interface for resource content, which includes metadata about the resource such as its URI, name, description, MIME type, size, and annotations.
static interface	McpSchema.ResourceContents	The contents of a specific resource or sub-resource.
static final record	McpSchema.ResourceLink	A known resource that the server is capable of reading.
static final record	McpSchema.ResourceReference	A reference to a resource or resource template definition for completion requests.
static final record	McpSchema.ResourcesUpdatedNotification	The Model Context Protocol (MCP) provides a standardized way for servers to send resources update message to clients.
static final record	McpSchema.ResourceTemplate	Resource templates allow servers to expose parameterized resources using URI
static interface	McpSchema.Result
static enum	McpSchema.Role
static final record	McpSchema.Root	Represents a root directory or file that the server can operate on.
static final record	McpSchema.SamplingMessage	Describes a message issued to or received from an LLM API.
static final record	McpSchema.ServerCapabilities	Capabilities that a server may support.
static final record	McpSchema.SetLevelRequest	A request from the client to the server, to enable or adjust logging.
static final record	McpSchema.StringSchema	Schema for a text input field in a form-based elicitation request.
static final record	McpSchema.SubscribeRequest	Sent from the client to request resources/updated notifications from the server whenever a particular resource changes.
static final record	McpSchema.TextContent	Text provided to or from an LLM.
static final record	McpSchema.TextResourceContents	Text contents of a resource.
static final record	McpSchema.TitledMultiSelectEnumSchema	Schema for multiple-selection enumeration with display titles for each option.
static final record	McpSchema.TitledMultiSelectItems	The items schema for McpSchema.TitledMultiSelectEnumSchema, describing the allowed enum options with display labels.
static final record	McpSchema.TitledSingleSelectEnumSchema	Schema for single-selection enumeration with display titles for each option.
static final record	McpSchema.Tool	Represents a tool that the server provides.
static final record	McpSchema.ToolAnnotations	Additional properties describing a Tool to clients.
static final record	McpSchema.UnsubscribeRequest	Sent from the client to request cancellation of resources/updated notifications from the server.
static final record	McpSchema.UntitledMultiSelectEnumSchema	Schema for multiple-selection enumeration without display titles for options.
static final record	McpSchema.UntitledMultiSelectItems	The items schema for McpSchema.UntitledMultiSelectEnumSchema, describing the allowed enum values.
static final record	McpSchema.UntitledSingleSelectEnumSchema	Schema for single-selection enumeration without display titles for options.

Field Summary

Fields

Modifier and Type	Field	Description
static final String	FIRST_PAGE
static final String	JSON_SCHEMA_DIALECT_2020_12	The JSON Schema 2020-12 meta-schema URI (SEP-1613).
static final String	JSONRPC_VERSION
static final String	METHOD_COMPLETION_COMPLETE
static final String	METHOD_ELICITATION_CREATE
static final String	METHOD_INITIALIZE
static final String	METHOD_LOGGING_SET_LEVEL
static final String	METHOD_NOTIFICATION_ELICITATION_COMPLETE
static final String	METHOD_NOTIFICATION_INITIALIZED
static final String	METHOD_NOTIFICATION_MESSAGE
static final String	METHOD_NOTIFICATION_PROGRESS
static final String	METHOD_NOTIFICATION_PROMPTS_LIST_CHANGED
static final String	METHOD_NOTIFICATION_RESOURCES_LIST_CHANGED
static final String	METHOD_NOTIFICATION_RESOURCES_UPDATED
static final String	METHOD_NOTIFICATION_ROOTS_LIST_CHANGED
static final String	METHOD_NOTIFICATION_TOOLS_LIST_CHANGED
static final String	METHOD_PING
static final String	METHOD_PROMPT_GET
static final String	METHOD_PROMPT_LIST
static final String	METHOD_RESOURCES_LIST
static final String	METHOD_RESOURCES_READ
static final String	METHOD_RESOURCES_SUBSCRIBE
static final String	METHOD_RESOURCES_TEMPLATES_LIST
static final String	METHOD_RESOURCES_UNSUBSCRIBE
static final String	METHOD_ROOTS_LIST
static final String	METHOD_SAMPLING_CREATE_MESSAGE
static final String	METHOD_TOOLS_CALL
static final String	METHOD_TOOLS_LIST

Method Summary

Modifier and Type	Method	Description
static McpSchema.JSONRPCMessage	deserializeJsonRpcMessage(McpJsonMapper jsonMapper, String jsonText)	Deserializes a JSON string into a JSONRPCMessage object.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

JSONRPC_VERSION

public static final String JSONRPC_VERSION

See Also:

• Constant Field Values

FIRST_PAGE

public static final String FIRST_PAGE

JSON_SCHEMA_DIALECT_2020_12

public static final String JSON_SCHEMA_DIALECT_2020_12

The JSON Schema 2020-12 meta-schema URI (SEP-1613). This is the default dialect for all schema objects in MCP when no explicit $schema field is present.

See Also:

• Constant Field Values

METHOD_INITIALIZE

public static final String METHOD_INITIALIZE

See Also:

• Constant Field Values

METHOD_NOTIFICATION_INITIALIZED

public static final String METHOD_NOTIFICATION_INITIALIZED

See Also:

• Constant Field Values

METHOD_PING

public static final String METHOD_PING

See Also:

• Constant Field Values

METHOD_NOTIFICATION_PROGRESS

public static final String METHOD_NOTIFICATION_PROGRESS

See Also:

• Constant Field Values

METHOD_TOOLS_LIST

public static final String METHOD_TOOLS_LIST

See Also:

• Constant Field Values

METHOD_TOOLS_CALL

public static final String METHOD_TOOLS_CALL

See Also:

• Constant Field Values

METHOD_NOTIFICATION_TOOLS_LIST_CHANGED

public static final String METHOD_NOTIFICATION_TOOLS_LIST_CHANGED

See Also:

• Constant Field Values

METHOD_RESOURCES_LIST

public static final String METHOD_RESOURCES_LIST

See Also:

• Constant Field Values

METHOD_RESOURCES_READ

public static final String METHOD_RESOURCES_READ

See Also:

• Constant Field Values

METHOD_NOTIFICATION_RESOURCES_LIST_CHANGED

public static final String METHOD_NOTIFICATION_RESOURCES_LIST_CHANGED

See Also:

• Constant Field Values

METHOD_NOTIFICATION_RESOURCES_UPDATED

public static final String METHOD_NOTIFICATION_RESOURCES_UPDATED

See Also:

• Constant Field Values

METHOD_RESOURCES_TEMPLATES_LIST

public static final String METHOD_RESOURCES_TEMPLATES_LIST

See Also:

• Constant Field Values

METHOD_RESOURCES_SUBSCRIBE

public static final String METHOD_RESOURCES_SUBSCRIBE

See Also:

• Constant Field Values

METHOD_RESOURCES_UNSUBSCRIBE

public static final String METHOD_RESOURCES_UNSUBSCRIBE

See Also:

• Constant Field Values

METHOD_PROMPT_LIST

public static final String METHOD_PROMPT_LIST

See Also:

• Constant Field Values

METHOD_PROMPT_GET

public static final String METHOD_PROMPT_GET

See Also:

• Constant Field Values

METHOD_NOTIFICATION_PROMPTS_LIST_CHANGED

public static final String METHOD_NOTIFICATION_PROMPTS_LIST_CHANGED

See Also:

• Constant Field Values

METHOD_COMPLETION_COMPLETE

public static final String METHOD_COMPLETION_COMPLETE

See Also:

• Constant Field Values

METHOD_LOGGING_SET_LEVEL

public static final String METHOD_LOGGING_SET_LEVEL

See Also:

• Constant Field Values

METHOD_NOTIFICATION_MESSAGE

public static final String METHOD_NOTIFICATION_MESSAGE

See Also:

• Constant Field Values

METHOD_ROOTS_LIST

public static final String METHOD_ROOTS_LIST

See Also:

• Constant Field Values

METHOD_NOTIFICATION_ROOTS_LIST_CHANGED

public static final String METHOD_NOTIFICATION_ROOTS_LIST_CHANGED

See Also:

• Constant Field Values

METHOD_SAMPLING_CREATE_MESSAGE

public static final String METHOD_SAMPLING_CREATE_MESSAGE

See Also:

• Constant Field Values

METHOD_ELICITATION_CREATE

public static final String METHOD_ELICITATION_CREATE

See Also:

• Constant Field Values

METHOD_NOTIFICATION_ELICITATION_COMPLETE

public static final String METHOD_NOTIFICATION_ELICITATION_COMPLETE

See Also:

• Constant Field Values

Method Details

deserializeJsonRpcMessage

public static McpSchema.JSONRPCMessage deserializeJsonRpcMessage(McpJsonMapper jsonMapper,
 String jsonText)
                                                          throws IOException

Deserializes a JSON string into a JSONRPCMessage object.

Parameters:

jsonMapper - The JsonMapper instance to use for deserialization

jsonText - The JSON string to deserialize

Returns:

A JSONRPCMessage instance using either the McpSchema.JSONRPCRequest, McpSchema.JSONRPCNotification, or McpSchema.JSONRPCResponse classes.

Throws:

IOException - If there's an error during deserialization

IllegalArgumentException - If the JSON structure doesn't match any known message type