Module methods 

Canonical MCP JSON-RPC method names.

Centralizing these as constants prevents the class of typo bug where a method name is spelled slightly wrong at a call site (e.g. the lifecycle notification notifications/initialized being sent as bare initialized), which the wire protocol silently ignores rather than rejecting.

Structs

Final2026Method

Exact direction and envelope metadata for one active MCP 2026-07-28 core method.

Legacy2024ClientCapabilities

Typed shape of the 2024-11-05 client capabilities object.

Legacy2024ListChangedCapability

Exact 2024-11-05 listChanged capability shape.

Legacy2024Method

Exact direction, envelope, and capability metadata for one tagged legacy method.

Legacy2024ResourcesCapability

Exact 2024-11-05 resources capability shape.

Legacy2024RootsCapability

Exact 2024-11-05 root capability shape.

Legacy2024ServerCapabilities

Typed shape of the 2024-11-05 server capabilities object.

Legacy2024WireError

An exact-2024 raw wire admission failure.

Enums

Final2026Direction

Direction permitted by the active MCP 2026-07-28 core message unions.

Final2026EnvelopeKind

JSON-RPC envelope kind required by an active MCP 2026-07-28 core method.

Final2026Peer

Peer that originated an MCP 2026-07-28 core message.

Legacy2024Capability

Capability shape that owns a tagged method in the pinned legacy schema.

Legacy2024Direction

Direction permitted by the 2024-11-05 tagged union.

Legacy2024Envelope

A decoded exact-2024 JSON-RPC envelope.

Legacy2024EnvelopeError

One exact-2024 admission failure, split by JSON-RPC error taxonomy.

Legacy2024EnvelopeKind

JSON-RPC envelope kind required for a tagged method.

Legacy2024ResultDisposition

Exact disposition of a result at the 2024-11-05 shared-result boundary.

Legacy2024ResultKind

Classifies a server result after exact-2024 lossless admission.

Constants

COMPLETION_COMPLETE

Completion request.

FINAL_2026_07_28_METHODS

All and only the method literals in the active MCP 2026-07-28 core request and notification unions.

INITIALIZE

Lifecycle initialize request.

LEGACY_2024_11_05_METHODS

All and only the 24 method literals in the pinned MCP 2024-11-05 schema.

LEGACY_2024_11_05_PROTOCOL_VERSION

The only legacy MCP wire version represented by this isolated surface.

LEGACY_2024_11_05_SCHEMA_JSON

Exact official MCP 2024-11-05 Draft 7 JSON schema, vendored as a read-only source input. This is deliberately not synthesized from newer protocol types: consumers can inspect the pinned source of truth directly.

LEGACY_2024_11_05_SCHEMA_SHA256

SHA-256 of the pinned official 2024-11-05 JSON schema.

LOGGING_SET_LEVEL

Logging set-level request.

NOTIFICATIONS_CANCELLED

Cancellation notification.

NOTIFICATIONS_INITIALIZED

Lifecycle initialized notification (spec-correct name).

NOTIFICATIONS_MESSAGE

Logging message notification.

NOTIFICATIONS_PROGRESS

Progress notification, valid in either direction.

NOTIFICATIONS_PROMPTS_LIST_CHANGED

Prompt-list-change notification.

NOTIFICATIONS_RESOURCES_LIST_CHANGED

Resource-list-change notification.

NOTIFICATIONS_RESOURCES_UPDATED

Resource-update notification.

NOTIFICATIONS_ROOTS_LIST_CHANGED

Roots-list-change notification.

NOTIFICATIONS_SUBSCRIPTIONS_ACKNOWLEDGED

Final subscription-established notification.

NOTIFICATIONS_TOOLS_LIST_CHANGED

Tool-list-change notification.

PING

Ping request.

PROMPTS_GET

Prompts get request.

PROMPTS_LIST

Prompts list request.

RESOURCES_LIST

Resources list request.

RESOURCES_READ

Resources read request.

RESOURCES_SUBSCRIBE

Resource-subscription request.

RESOURCES_TEMPLATES_LIST

Resource templates list request.

RESOURCES_UNSUBSCRIBE

Resource-unsubscription request.

ROOTS_LIST

Server-to-client roots list request.

SAMPLING_CREATE_MESSAGE

Server-to-client sampling request.

SERVER_DISCOVER

Final stateless server-discovery request.

SUBSCRIPTIONS_LISTEN

Final long-lived subscription request.

TOOLS_CALL

Tools call request.

TOOLS_LIST

Tools list request.

Functions

classify_legacy_2024_result

Classifies a result before it can cross from shared handling to exact 2024.

decode_legacy_2024_11_05_client_capabilities

Validates and decodes the exact 2024-11-05 client capability shape.

decode_legacy_2024_11_05_envelope

Decodes one exact MCP 2024-11-05 JSON-RPC envelope before any lifecycle or dispatch work. Top-level batches, modern method literals, invalid IDs, and 2025-11-25 initialization are rejected at this pure raw-admission boundary.

decode_legacy_2024_11_05_envelope_classified

Decodes one exact-2024 envelope, classifying failures by taxonomy.

decode_legacy_2024_11_05_server_capabilities

Validates and decodes the exact 2024-11-05 server capability shape.

final_2026_07_28_method

Looks up one exact active MCP 2026-07-28 core method literal.

legacy_2024_11_05_method

Looks up one exact tagged 2024-11-05 method literal.

legacy_2024_11_05_schema

Parses the pinned legacy schema, retaining its exact source bytes in LEGACY_2024_11_05_SCHEMA_JSON.

translate_legacy_2024_result

Returns an ordinary complete result unchanged only when it has an exact 2024 representation for method.

validate_legacy_2024_11_05_initialize_result

Validates initialization-era server metadata before a consumer accepts it.

validate_legacy_2024_11_05_method_params

Validates the required exact-2024 parameter members for the methods used by the server adapter. JSON-RPC itself already guarantees an object whenever parameters are present; this function adds the pinned method-level shape.