openapi: 3.1.0 jsonSchemaDialect: "https://json-schema.org/draft/2020-12/schema" $id: https://modelcontextprotocol.io/schemas/draft/2025-12-01/server-registry-openapi info: title: MCP Server Registry API version: "2025-12-01" summary: API for discovering and accessing MCP server metadata description: | Specification for a theoretical REST API that serves up metadata about MCP servers. license: name: MIT identifier: MIT tags: - name: servers description: Operations for discovering and retrieving MCP servers - name: publish description: Operations for publishing MCP servers to the registry paths: /v0.1/servers: get: tags: [servers] summary: List MCP servers description: Returns a list of all registered MCP servers parameters: - name: cursor in: query description: | Pagination cursor for retrieving next set of results. Cursors are opaque strings returned in the `metadata.nextCursor` field of paginated responses. Always use the exact cursor value returned by the API. required: false schema: type: string - name: limit in: query description: Maximum number of items to return required: false schema: type: integer - name: search in: query description: Search servers by name (substring match) required: false schema: type: string example: "filesystem" - name: updated_since in: query description: Filter servers updated since timestamp (RFC3339 datetime) required: false schema: type: string format: date-time example: "2025-08-07T13:15:04.280Z" - name: version in: query description: Filter by version ('latest' for latest version, or an exact version like '1.2.3') required: false schema: type: string example: "1.2.3" - name: include_deleted in: query description: Include deleted servers in results (default false, but always true when updated_since is provided) required: false schema: type: boolean default: false responses: '200': description: A list of MCP servers content: application/json: schema: $ref: '#/components/schemas/ServerList' /v0.1/servers/{serverName}/versions: get: tags: [servers] summary: List all versions of an MCP server description: Returns all available versions for a specific MCP server, ordered by publication date (newest first) parameters: - name: serverName in: path required: true description: URL-encoded server name (e.g., "com.example%2Fmy-server") schema: type: string example: "com.example%2Fmy-server" - name: include_deleted in: query description: Include deleted servers in results (default false) required: false schema: type: boolean default: false responses: '200': description: A list of all versions for the server content: application/json: schema: $ref: '#/components/schemas/ServerList' '404': description: Server not found content: application/json: schema: type: object properties: error: type: string example: "Server not found" /v0.1/servers/{serverName}/versions/{version}: get: tags: [servers] summary: Get specific MCP server version description: Returns detailed information about a specific version of an MCP server. Use the special version `latest` to get the latest version. parameters: - name: serverName in: path required: true description: URL-encoded server name (e.g., "com.example%2Fmy-server") schema: type: string example: "com.example%2Fmy-server" - name: version in: path required: true description: URL-encoded version to retrieve (e.g., "1.0.0" or "1.0.0%2B20130313144700" for versions with build metadata) schema: type: string example: "1.0.0" - name: include_deleted in: query description: Include deleted servers in results (default false) required: false schema: type: boolean default: false responses: '200': description: Detailed server information content: application/json: schema: $ref: '#/components/schemas/ServerResponse' '404': description: Server or version not found content: application/json: schema: type: object properties: error: type: string example: "Server not found" put: tags: [publish] summary: Update specific MCP server version (Optional) description: | Update a specific version of an MCP server in the registry. **Note**: This endpoint is optional for registry implementations and is not implemented by the official MCP registry. It is included in the specification to standardize the update mechanism for registry implementations that choose to support it. Authentication mechanism is registry-specific and may vary between implementations. security: - bearerAuth: [] parameters: - name: serverName in: path required: true description: URL-encoded server name (e.g., "com.example%2Fmy-server") schema: type: string example: "com.example%2Fmy-server" - name: version in: path required: true description: URL-encoded version to update (e.g., "1.0.0" or "1.0.0%2B20130313144700" for versions with build metadata) schema: type: string example: "1.0.0" requestBody: required: true content: application/json: schema: $ref: '#/components/schemas/ServerDetail' responses: '200': description: Successfully updated server version content: application/json: schema: $ref: '#/components/schemas/ServerResponse' '401': description: Unauthorized - Invalid or missing authentication token content: application/json: schema: type: object properties: error: type: string example: "Invalid or expired Registry JWT token" '403': description: Forbidden - Insufficient permissions content: application/json: schema: type: object properties: error: type: string example: "You do not have permission to update this server" '404': description: Server or version not found content: application/json: schema: type: object properties: error: type: string example: "Server version not found" '500': description: Internal server error content: application/json: schema: type: object properties: error: type: string example: "Failed to update server version" '501': description: Not Implemented - Registry does not support updates content: application/json: schema: type: object properties: error: type: string example: "Updates are not supported by this registry" delete: tags: [publish] summary: Delete specific MCP server version (Optional) description: | Delete a specific version of an MCP server from the registry. **Note**: This endpoint is optional for registry implementations and is not implemented by the official MCP registry. It is included in the specification to standardize the deletion mechanism for registry implementations that choose to support it. Authentication mechanism is registry-specific and may vary between implementations. security: - bearerAuth: [] parameters: - name: serverName in: path required: true description: URL-encoded server name (e.g., "com.example%2Fmy-server") schema: type: string example: "com.example%2Fmy-server" - name: version in: path required: true description: URL-encoded version to delete (e.g., "1.0.0" or "1.0.0%2B20130313144700" for versions with build metadata) schema: type: string example: "1.0.0" responses: '200': description: Successfully deleted server version content: application/json: schema: $ref: '#/components/schemas/ServerResponse' '401': description: Unauthorized - Invalid or missing authentication token content: application/json: schema: type: object properties: error: type: string example: "Invalid or expired Registry JWT token" '403': description: Forbidden - Insufficient permissions content: application/json: schema: type: object properties: error: type: string example: "You do not have permission to delete this server" '404': description: Server or version not found content: application/json: schema: type: object properties: error: type: string example: "Server version not found" '500': description: Internal server error content: application/json: schema: type: object properties: error: type: string example: "Failed to delete server version" '501': description: Not Implemented - Registry does not support deletion content: application/json: schema: type: object properties: error: type: string example: "Deletion is not supported by this registry" /v0.1/servers/{serverName}/versions/{version}/status: patch: tags: [publish] summary: Update server version status description: | Update the lifecycle status of a specific server version. Requires `publish` or `edit` permission for the server namespace. security: - bearerAuth: [] parameters: - name: serverName in: path required: true description: URL-encoded server name (e.g., "com.example%2Fmy-server") schema: type: string example: "com.example%2Fmy-server" - name: version in: path required: true description: URL-encoded version to update schema: type: string example: "1.0.0" requestBody: required: true content: application/json: schema: $ref: '#/components/schemas/StatusUpdateRequest' responses: '200': description: Successfully updated server status content: application/json: schema: $ref: '#/components/schemas/ServerResponse' '400': description: Bad request - Invalid status transition or no changes to apply content: application/json: schema: type: object properties: error: type: string example: "No changes to apply: status is already deprecated" '401': description: Unauthorized - Invalid or missing authentication token content: application/json: schema: type: object properties: error: type: string example: "Invalid or expired Registry JWT token" '403': description: Forbidden - Insufficient permissions content: application/json: schema: type: object properties: error: type: string example: "You do not have publish or edit permissions for this server" '404': description: Server version not found content: application/json: schema: type: object properties: error: type: string example: "Server version not found" /v0.1/servers/{serverName}/status: patch: tags: [publish] summary: Update status for all server versions description: | Update the lifecycle status of all versions of a server in a single transaction. Either all versions are updated or none on failure. Requires `publish` or `edit` permission for the server namespace. security: - bearerAuth: [] parameters: - name: serverName in: path required: true description: URL-encoded server name (e.g., "com.example%2Fmy-server") schema: type: string example: "com.example%2Fmy-server" requestBody: required: true content: application/json: schema: $ref: '#/components/schemas/StatusUpdateRequest' responses: '200': description: Successfully updated all versions content: application/json: schema: $ref: '#/components/schemas/AllVersionsStatusResponse' '400': description: Bad request - Invalid status value content: application/json: schema: type: object properties: error: type: string example: "Invalid status value" '401': description: Unauthorized - Invalid or missing authentication token content: application/json: schema: type: object properties: error: type: string example: "Invalid or expired Registry JWT token" '403': description: Forbidden - Insufficient permissions content: application/json: schema: type: object properties: error: type: string example: "You do not have publish or edit permissions for this server" '404': description: Server not found content: application/json: schema: type: object properties: error: type: string example: "Server not found" /v0.1/publish: post: tags: [publish] summary: Publish MCP server (Optional) description: | Publish a new MCP server to the registry or update an existing one. **Note**: This endpoint is optional for registry implementations. Read-only registries may not provide this functionality. Authentication mechanism is registry-specific and may vary between implementations. security: - bearerAuth: [] requestBody: required: true content: application/json: schema: $ref: '#/components/schemas/ServerDetail' examples: basic_server: summary: Basic server with NPM package value: name: "io.modelcontextprotocol/filesystem" description: "Node.js server implementing Model Context Protocol (MCP) for filesystem operations." title: "Filesystem" repository: url: "https://github.com/modelcontextprotocol/servers" source: "github" version: "1.0.2" packages: - registryType: "npm" registryBaseUrl: "https://registry.npmjs.org" identifier: "@modelcontextprotocol/server-filesystem" version: "1.0.2" _meta: io.modelcontextprotocol.registry/publisher-provided: tool: "publisher-cli" version: "1.2.3" buildInfo: commit: "abc123def456" timestamp: "2023-12-01T10:30:00Z" example_org_server: summary: Server with example.com organization extensions value: name: "com.example/demo-server" description: "Example MCP server demonstrating publisher extensions." title: "Demo Server" repository: url: "https://github.com/example/mcp-demo" source: "github" version: "1.0.0" packages: - registryType: "npm" registryBaseUrl: "https://registry.npmjs.org" identifier: "@example/mcp-demo-server" version: "1.0.0" _meta: io.modelcontextprotocol.registry/publisher-provided: contactEmail: "maintainer@example.com" buildMetadata: commit: "abc123" timestamp: "2024-01-15T10:30:00Z" com.example: marketplaceIcon: "https://example.com/icon.png" category: ["software_development"] documentationUrl: "https://docs.example.org" verifiedPublisher: true responses: '200': description: Successfully published server content: application/json: schema: $ref: '#/components/schemas/ServerResponse' '401': description: Unauthorized - Invalid or missing authentication token content: application/json: schema: type: object properties: error: type: string example: "Invalid or expired Registry JWT token" '403': description: Forbidden - Insufficient permissions content: application/json: schema: type: object properties: error: type: string example: "You do not have permission to publish this server" '500': description: Internal server error content: application/json: schema: type: object properties: error: type: string example: "Failed to publish server" '501': description: Not Implemented - Registry does not support publishing content: application/json: schema: type: object properties: error: type: string example: "Publishing is not supported by this registry" components: securitySchemes: bearerAuth: type: http scheme: bearer bearerFormat: JWT description: | Registry-specific authentication token. The authentication mechanism and token format may vary between registry implementations. Some registries may use JWT tokens, others may use API keys or OAuth. Consult your specific registry's authentication documentation. schemas: Repository: type: object description: "Repository metadata for the MCP server source code. Enables users and security experts to inspect the code, improving transparency." required: - url - source properties: url: type: string format: uri description: "Repository URL for browsing source code. Should support both web browsing and git clone operations." example: "https://github.com/modelcontextprotocol/servers" source: type: string description: "Repository hosting service identifier. Used by registries to determine validation and API access methods." example: "github" id: type: string description: "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. For GitHub, use: gh api repos// --jq '.id'" example: "b94b5f7e-c7c6-d760-2c78-a5e9b8a5b8c9" subfolder: type: string description: "Optional relative path from repository root to the server location within a monorepo or nested package structure. Must be a clean relative path." example: "src/everything" ServerList: type: object required: - servers properties: servers: type: array items: $ref: '#/components/schemas/ServerResponse' metadata: type: object properties: nextCursor: type: string description: | Pagination cursor for retrieving the next page of results. Use this exact value in the `cursor` query parameter of your next request. If null or empty, there are no more results. count: type: integer description: Number of items in current page example: 30 Package: type: object required: - registryType - identifier - transport properties: registryType: type: string description: Registry type indicating how to download packages (e.g., 'npm', 'pypi', 'oci', 'nuget', 'mcpb') examples: - "npm" - "pypi" - "oci" - "nuget" - "mcpb" registryBaseUrl: type: string format: uri description: Base URL of the package registry examples: - "https://registry.npmjs.org" - "https://pypi.org" - "https://docker.io" - "https://api.nuget.org/v3/index.json" - "https://github.com" - "https://gitlab.com" identifier: type: string description: Package identifier - either a package name (for registries) or URL (for direct downloads) examples: - "@modelcontextprotocol/server-brave-search" - "https://github.com/example/releases/download/v1.0.0/package.mcpb" version: type: string description: "Package version. Must be a specific version. Version ranges are rejected (e.g., '^1.2.3', '~1.2.3', '>=1.2.3', '1.x', '1.*')." example: "1.0.2" minLength: 1 not: const: "latest" fileSha256: type: string description: "SHA-256 hash of the package file for integrity verification. Required for MCPB packages and optional for other package types. Authors are responsible for generating correct SHA-256 hashes when creating server.json. If present, MCP clients must validate the downloaded file matches the hash before running packages to ensure file integrity." example: "fe333e598595000ae021bd27117db32ec69af6987f507ba7a63c90638ff633ce" pattern: "^[a-f0-9]{64}$" runtimeHint: type: string description: A hint to help clients determine the appropriate runtime for the package. This field should be provided when `runtimeArguments` are present. examples: [npx, uvx, docker, dnx] transport: $ref: '#/components/schemas/LocalTransport' description: Transport protocol configuration for the package runtimeArguments: type: array description: A list of arguments to be passed to the package's runtime command (such as docker or npx). The `runtimeHint` field should be provided when `runtimeArguments` are present. items: $ref: '#/components/schemas/Argument' packageArguments: type: array description: A list of arguments to be passed to the package's binary. items: $ref: '#/components/schemas/Argument' environmentVariables: type: array description: A mapping of environment variables to be set when running the package. items: $ref: '#/components/schemas/KeyValueInput' Input: type: object properties: description: description: A description of the input, which clients can use to provide context to the user. type: string isRequired: type: boolean default: false format: type: string description: "Specifies the input format. Supported values include `filepath`, which should be interpreted as a file on the user's filesystem.\n\nWhen the input is converted to a string, booleans should be represented by the strings \"true\" and \"false\", and numbers should be represented as decimal values." enum: [string, number, boolean, filepath] default: string value: type: string description: | The value for the input. If this is not set, the user may be prompted to provide a value. If a value is set, it should not be configurable by end users. Identifiers wrapped in `{curly_braces}` will be replaced with the corresponding properties from the input `variables` map. If an identifier in braces is not found in `variables`, or if `variables` is not provided, the `{curly_braces}` substring should remain unchanged. isSecret: type: boolean description: Indicates whether the input is a secret value (e.g., password, token). If true, clients should handle the value securely. default: false default: type: string description: "The default value for the input. This should be a valid value for the input. If you want to provide input examples or guidance, use the `placeholder` field instead." placeholder: type: string description: "A placeholder for the input to be displaying during configuration. This is used to provide examples or guidance about the expected form or content of the input." choices: type: array description: A list of possible values for the input. If provided, the user must select one of these values. items: type: string example: [] InputWithVariables: allOf: - $ref: '#/components/schemas/Input' - type: object properties: variables: type: object description: A map of variable names to their values. Keys in the input `value` that are wrapped in `{curly_braces}` will be replaced with the corresponding variable values. additionalProperties: $ref: '#/components/schemas/Input' PositionalArgument: description: A positional input is a value inserted verbatim into the command line. allOf: - $ref: '#/components/schemas/InputWithVariables' - type: object required: - type properties: type: type: string enum: [positional] example: "positional" valueHint: type: string description: "An identifier for the positional argument. It is not part of the command line. It may be used by client configuration as a label identifying the argument. It is also used to identify the value in transport URL variable substitution." example: file_path isRepeated: type: boolean description: Whether the argument can be repeated multiple times in the command line. default: false anyOf: - required: - valueHint - required: - value NamedArgument: description: A command-line `--flag={value}`. allOf: - $ref: '#/components/schemas/InputWithVariables' - type: object required: - type - name properties: type: type: string enum: [named] example: "named" name: type: string description: The flag name, including any leading dashes. example: "--port" isRepeated: type: boolean description: Whether the argument can be repeated multiple times. default: false KeyValueInput: allOf: - $ref: '#/components/schemas/InputWithVariables' - type: object required: - name properties: name: type: string description: Name of the header or environment variable. example: SOME_VARIABLE Argument: description: "Warning: Arguments construct command-line parameters that may contain user-provided input. This creates potential command injection risks if clients execute commands in a shell environment. For example, a malicious argument value like ';rm -rf ~/Development' could execute dangerous commands. Clients should prefer non-shell execution methods (e.g., posix_spawn) when possible to eliminate injection risks entirely. Where not possible, clients should obtain consent from users or agents to run the resolved command before execution." anyOf: - $ref: '#/components/schemas/PositionalArgument' - $ref: '#/components/schemas/NamedArgument' StdioTransport: type: object required: - type properties: type: type: string enum: [stdio] description: Transport type example: "stdio" StreamableHttpTransport: type: object required: - type - url properties: type: type: string enum: [streamable-http] description: Transport type example: "streamable-http" url: type: string description: "URL template for the streamable-http transport. Must start with http://, https://, or a template variable (e.g., {baseUrl}). Variables in {curly_braces} are resolved based on context: In Package context, they reference argument valueHints, argument names, or environment variable names from the parent Package. In Remote context, they reference variables from the transport's 'variables' object. After variable substitution, this should produce a valid URI." example: "https://api.example.com/mcp" pattern: "^(https?://[^\\s]+|\\{[a-zA-Z_][a-zA-Z0-9_]*\\}[^\\s]*)$" headers: type: array description: HTTP headers to include items: $ref: '#/components/schemas/KeyValueInput' SseTransport: type: object required: - type - url properties: type: type: string enum: [sse] description: Transport type example: "sse" url: type: string description: "Server-Sent Events endpoint URL template. Must start with http://, https://, or a template variable (e.g., {baseUrl}). Variables in {curly_braces} are resolved based on context: In Package context, they reference argument valueHints, argument names, or environment variable names from the parent Package. In Remote context, they reference variables from the transport's 'variables' object. After variable substitution, this should produce a valid URI." example: "https://mcp-fs.example.com/sse" pattern: "^(https?://[^\\s]+|\\{[a-zA-Z_][a-zA-Z0-9_]*\\}[^\\s]*)$" headers: type: array description: HTTP headers to include items: $ref: '#/components/schemas/KeyValueInput' LocalTransport: anyOf: - $ref: '#/components/schemas/StdioTransport' - $ref: '#/components/schemas/StreamableHttpTransport' - $ref: '#/components/schemas/SseTransport' description: Transport protocol configuration for local/package context RemoteTransport: allOf: - anyOf: - $ref: '#/components/schemas/StreamableHttpTransport' - $ref: '#/components/schemas/SseTransport' - type: object properties: variables: type: object description: "Configuration variables that can be referenced in URL template {curly_braces}. The key is the variable name, and the value defines the variable properties." additionalProperties: $ref: '#/components/schemas/Input' description: Transport protocol configuration for remote context - extends StreamableHttpTransport or SseTransport with variables Icon: type: object description: An optionally-sized icon that can be displayed in a user interface. required: - src properties: src: type: string format: uri description: "A standard URI pointing to an icon resource. Must be an HTTPS URL. Consumers SHOULD take steps to ensure URLs serving icons are from the same domain as the server or a trusted domain. Consumers SHOULD take appropriate precautions when consuming SVGs as they can contain executable JavaScript." example: "https://example.com/icon.png" maxLength: 255 mimeType: type: string description: "Optional MIME type override if the source MIME type is missing or generic. Must be one of: image/png, image/jpeg, image/jpg, image/svg+xml, image/webp." enum: [image/png, image/jpeg, image/jpg, image/svg+xml, image/webp] example: "image/png" sizes: type: array description: "Optional array of strings that specify sizes at which the icon can be used. Each string should be in WxH format (e.g., '48x48', '96x96') or 'any' for scalable formats like SVG. If not provided, the client should assume that the icon can be used at any size." items: type: string pattern: "^(\\d+x\\d+|any)$" examples: - ["48x48", "96x96"] - ["any"] theme: type: string description: "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." enum: [light, dark] ServerDetail: description: Schema for a static representation of an MCP server. Used in various contexts related to discovery, installation, and configuration. type: object required: - name - description - version properties: name: type: string description: "Server name in reverse-DNS format. Must contain exactly one forward slash separating namespace from server name." example: "io.github.user/weather" minLength: 3 maxLength: 200 pattern: "^[a-zA-Z0-9.-]+/[a-zA-Z0-9._-]+$" description: type: string description: "Clear human-readable explanation of server functionality. Should focus on capabilities, not implementation details." example: "MCP server providing weather data and forecasts via OpenWeatherMap API" minLength: 1 maxLength: 100 title: type: string description: "Optional human-readable title or display name for the MCP server. MCP subregistries or clients MAY choose to use this for display purposes." example: "Weather API" minLength: 1 maxLength: 100 repository: $ref: '#/components/schemas/Repository' description: "Optional repository metadata for the MCP server source code. Recommended for transparency and security inspection." version: type: string example: "1.0.2" description: "Version string for this server. SHOULD follow semantic versioning (e.g., '1.0.2', '2.1.0-alpha'). Equivalent of Implementation.version in 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 websiteUrl: type: string format: uri description: "Optional URL to the server's homepage, documentation, or project website. This provides a central link for users to learn more about the server. Particularly useful when the server has custom installation instructions or setup requirements." example: "https://modelcontextprotocol.io/examples" icons: type: array description: "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)." items: $ref: '#/components/schemas/Icon' $schema: type: string format: uri description: JSON Schema URI for this server.json format example: "https://static.modelcontextprotocol.io/schemas/2025-12-11/server.schema.json" packages: type: array items: $ref: '#/components/schemas/Package' remotes: type: array items: $ref: '#/components/schemas/RemoteTransport' _meta: type: object description: "Extension metadata using reverse DNS namespacing for vendor-specific data" properties: io.modelcontextprotocol.registry/publisher-provided: type: object description: "Publisher-provided metadata for downstream registries" additionalProperties: true example: tool: "publisher-cli" version: "1.2.3" buildInfo: commit: "abc123def456" timestamp: "2023-12-01T10:30:00Z" pipelineId: "build-789" ServerResponse: description: API response format with separated server data and registry metadata type: object required: - server properties: server: $ref: '#/components/schemas/ServerDetail' _meta: type: object description: Registry-managed metadata properties: io.modelcontextprotocol.registry/official: type: object description: Official MCP registry metadata properties: status: type: string enum: ["active", "deprecated", "deleted"] description: Server lifecycle status example: "active" statusMessage: type: string description: Optional message explaining the status (e.g., deprecation reason) example: "Please upgrade to version 2.0.0" maxLength: 500 publishedAt: type: string format: date-time description: Timestamp when the server was first published to the registry example: "2023-12-01T10:30:00Z" updatedAt: type: string format: date-time description: Timestamp when the server entry was last updated example: "2023-12-01T11:00:00Z" isLatest: type: boolean description: Whether this is the latest version of the server example: true additionalProperties: false additionalProperties: true StatusUpdateRequest: description: Request body for updating server status type: object required: - status properties: status: type: string enum: ["active", "deprecated", "deleted"] description: New server lifecycle status example: "deprecated" statusMessage: type: string description: Optional message explaining the status change (e.g., deprecation reason) example: "Please upgrade to version 2.0.0" maxLength: 500 AllVersionsStatusResponse: description: Response from bulk status update for all versions type: object required: - updatedCount - servers properties: updatedCount: type: integer description: Number of versions updated example: 3 servers: type: array description: List of all updated server versions items: $ref: '#/components/schemas/ServerResponse'