/** * MCP Server Cards * * Schema for the experimental Server Card extension. This file is the single * source of truth for the Server Card types. */ /** * A static metadata document describing a remote MCP server, suitable for * pre-connection discovery. A Server Card may be hosted at any unreserved URI; * MCP reserves `GET /server-card` as the recommended * location. Clients learn a card's URL from an [AI Catalog](https://github.com/Agent-Card/ai-catalog) * rather than guessing it. * * Server Cards describe only what is needed to discover and connect to a remote server: * identity, transport, and protocol versions. * * They do not enumerate primitives (tools, resources, prompts) — those remain * subject to runtime listing via the protocol's standard list operations. * * The fields a Server Card does declare (identity, transport, protocol * versions) are advisory, not authoritative: they should be consistent with * the server's `server/discover` response, and clients must not treat them as * authoritative for security decisions. See "Consistency with Runtime * Behavior" in docs/discovery.md for the normative requirement. * * @category Server Cards */ export interface ServerCard { /** * The Server Card JSON Schema URI that this document conforms to. Required. * * Must be the `/v1/` Server Card schema URL under * `static.modelcontextprotocol.io/schemas/` (i.e., * `https://static.modelcontextprotocol.io/schemas/v1/server-card.schema.json`). * Schema URLs are versioned by the `vN` segment rather than by date; a * breaking revision of the Server Card shape publishes a new `vN` family. * * @format uri * @pattern ^https://static\.modelcontextprotocol\.io/schemas/v1/server-card\.schema\.json$ */ $schema: string; /** * Server name in reverse-DNS format. Must contain exactly one forward slash * separating namespace from server name. * * @minLength 3 * @maxLength 200 * @pattern ^[a-zA-Z0-9.-]+/[a-zA-Z0-9._-]+$ */ name: string; /** * Version string for this server. SHOULD follow semantic versioning * (e.g., '1.0.2', '2.1.0-alpha'). Equivalent of `Implementation.version` * in the MCP specification. Non-semantic versions are allowed but may not * sort predictably. Version ranges are rejected (e.g., '^1.2.3', '~1.2.3', * '>=1.2.3', '1.x', '1.*'). * * @maxLength 255 */ version: string; /** * Clear human-readable explanation of server functionality. Should focus on * capabilities, not implementation details. * * @minLength 1 * @maxLength 100 */ description: string; /** * Optional human-readable title or display name for the MCP server. * MCP subregistries or clients MAY choose to use this for display purposes. * * @minLength 1 * @maxLength 100 */ title?: string; /** * Optional URL to the server's homepage, documentation, or project website. * Provides a central link for users to learn more about the server. * Particularly useful when the server has custom installation instructions * or setup requirements. * * @format uri */ websiteUrl?: string; /** * Optional repository metadata for the MCP server source code. * Recommended for transparency and security inspection. */ repository?: Repository; /** * Optional set of sized icons that the client can display in a user interface. * * Clients that support rendering icons MUST support at least the following * MIME types: `image/png` and `image/jpeg` (safe, universal compatibility). * Clients SHOULD also support: `image/svg+xml` (scalable but requires security * precautions) and `image/webp` (modern, efficient format). */ icons?: Icon[]; /** * Metadata helpful for making HTTP-based connections to this MCP server. */ remotes?: Remote[]; /** * Extension metadata using reverse-DNS namespacing for vendor-specific data. * * Follows the protocol's standard `_meta` definition. * * @see {@link MetaObject} */ _meta?: MetaObject; } /** * Repository metadata for the MCP server source code. Enables users and * security experts to inspect the code, improving transparency. * * @category Server Cards */ export interface Repository { /** * Repository URL for browsing source code. Should support both web browsing * and `git clone` operations. * * @format uri */ url: string; /** * Repository hosting service identifier (e.g., `"github"`). Used by registries * to determine validation and API access methods. */ source: string; /** * Optional relative path from repository root to the server location within a * monorepo or nested package structure. Must be a clean relative path. */ subfolder?: string; /** * Repository identifier from the hosting service (e.g., GitHub repo ID). * Owned and determined by the source forge. Should remain stable across * repository renames and may be used to detect repository resurrection * attacks — if a repository is deleted and recreated, the ID should change. */ id?: string; } /** * Metadata for connecting to a remote (HTTP-based) MCP server endpoint. * * @category Server Cards */ export interface Remote { /** * The transport type for this remote endpoint. */ type: "streamable-http" | "sse"; /** * URL template for the remote endpoint. Must start with `http://`, * `https://`, or a `{template-variable}`. Variables in `{curly_braces}` * are substituted from the {@link Remote.variables} map before the * client connects. * * @pattern ^(https?://[^\s]+|\{[a-zA-Z_][a-zA-Z0-9_]*\}[^\s]*)$ */ url: string; /** * HTTP headers required or accepted when connecting to this remote * endpoint. Each header is described as a {@link KeyValueInput} so that * clients can prompt users for required values, mark secrets, surface * defaults, and constrain to a list of choices. */ headers?: KeyValueInput[]; /** * Configuration variables that can be referenced as `{curly_braces}` * placeholders in `url` (and inside header values via * {@link KeyValueInput.variables}). The map key is the variable * name; the value defines the variable's properties (e.g., human-readable * description, default, whether it is required or secret). */ variables?: { [key: string]: Input }; /** * MCP protocol versions actively supported by this remote endpoint. Allows * clients to select a compatible protocol version before connecting. */ supportedProtocolVersions?: string[]; } /** * A user-supplied or pre-set input value, used for {@link Remote} URL * variables and header values. * * @category Server Cards */ export interface Input { /** * Human-readable explanation of the input. Clients can use this to provide * context to the user. */ description?: string; /** * Whether the input must be supplied for the connection to succeed. */ isRequired?: boolean; /** * Whether the input is a secret value (e.g., password, token). If true, * clients should handle the value securely. */ isSecret?: boolean; /** * Specifies the input format. `"filepath"` should be interpreted as a file * on the user's filesystem. When the input is converted to a string, * booleans should be represented by `"true"`/`"false"`, and numbers by * decimal values. */ format?: "string" | "number" | "boolean" | "filepath"; /** * Default value for the input. SHOULD be a valid value for the input. */ default?: string; /** * Placeholder displayed during configuration to provide examples or * guidance about the expected form of the input. */ placeholder?: string; /** * Pre-set value for the input. If set, the value should not be configurable * by end users. Identifiers wrapped in `{curly_braces}` will be replaced * with the corresponding entries from the input's `variables` map (if any). */ value?: string; /** * Allowed values for the input. If provided, the user must select one. */ choices?: string[]; } /** * A named {@link Input} — used for HTTP headers — whose `value` may reference * variables for substitution. * * @category Server Cards */ export interface KeyValueInput extends Input { /** * Name of the header. */ name: string; /** * Variables referenced by `{curly_braces}` identifiers in `value`. The map * key is the variable name; the value defines the variable's properties. */ variables?: { [key: string]: Input }; } /* ---------- Inlined dependencies from the main MCP spec ---------- */ /** * Represents the contents of a `_meta` field, which clients and servers use to attach additional metadata to their interactions. * * Certain key names are reserved by MCP for protocol-level metadata; implementations MUST NOT make assumptions about values at these keys. Additionally, specific schema definitions may reserve particular names for purpose-specific metadata, as declared in those definitions. * * Valid keys have two segments: * * **Prefix:** * - Optional — if specified, MUST be a series of _labels_ separated by dots (`.`), followed by a slash (`/`). * - Labels MUST start with a letter and end with a letter or digit. Interior characters may be letters, digits, or hyphens (`-`). * - Any prefix consisting of zero or more labels, followed by `modelcontextprotocol` or `mcp`, followed by any label, is **reserved** for MCP use. For example: `modelcontextprotocol.io/`, `mcp.dev/`, `api.modelcontextprotocol.org/`, and `tools.mcp.com/` are all reserved. * * **Name:** * - Unless empty, MUST start and end with an alphanumeric character (`[a-z0-9A-Z]`). * - Interior characters may be alphanumeric, hyphens (`-`), underscores (`_`), or dots (`.`). * * @see [General fields: `_meta`](https://modelcontextprotocol.io/specification/draft/basic#meta) for more details. * @category Common Types */ export interface MetaObject { [key: string]: unknown; } /** * An optionally-sized icon that can be displayed in a user interface. * * @category Common Types */ export interface Icon { /** * A standard URI pointing to an icon resource. May be an HTTP/HTTPS URL or a * `data:` URI with Base64-encoded image data. * * Consumers SHOULD take steps to ensure URLs serving icons are from the * same domain as the client/server or a trusted domain. * * Consumers SHOULD take appropriate precautions when consuming SVGs as they can contain * executable JavaScript. * * @format uri */ src: string; /** * Optional MIME type override if the source MIME type is missing or generic. * For example: `"image/png"`, `"image/jpeg"`, or `"image/svg+xml"`. */ mimeType?: string; /** * Optional array of strings that specify sizes at which the icon can be used. * Each string should be in WxH format (e.g., `"48x48"`, `"96x96"`) or `"any"` for scalable formats like SVG. * * If not provided, the client should assume that the icon can be used at any size. */ sizes?: string[]; /** * Optional specifier for the theme this icon is designed for. `"light"` indicates * the icon is designed to be used with a light background, and `"dark"` indicates * the icon is designed to be used with a dark background. * * If not provided, the client should assume the icon can be used with any theme. */ theme?: "light" | "dark"; }