Model Context Protocol is an open, JSON-RPC 2.0 protocol from Anthropic that standardizes how AI applications (hosts) connect to external systems via servers that expose tools, resources, and prompts. MCP is positioned as "a USB-C port for AI applications" and has become the de-facto integration layer for Claude, ChatGPT, Cursor, Visual Studio Code, and a growing ecosystem of agent runtimes. This topic repo catalogs the canonical specification, the official multi-language SDKs, the reference server collection, community registries (Smithery, Pulse MCP, Naftiko Sandbox), and major MCP-aware clients, plus the vocabulary, JSON Schema, JSON-LD, and example payloads needed to reason about the protocol.
Model Context Protocol (MCP) publishes 17 APIs on the APIs.io network. Tagged areas include MCP, AI Agents, Tools, Resources, and Prompts.
The Model Context Protocol (MCP) catalog on APIs.io includes 1 JSON-LD context and 1 Spectral governance ruleset.
Model Context Protocol (MCP)’s developer surface includes engineering blog, developer portal, documentation, and 13 more developer resources.
Create-or-Update Ergonomics could not be measured. We hold no machine-readable contract for
this provider to read, so there is nothing to measure a write surface against. Excluded rather than scored zero:
never-measured and measured-empty are different facts. Publishing an OpenAPI is what makes this facet — and
several others — scorable at all.
Improve this rating by publishing the missing artifacts — every area above can be raised, and the full rubric is at apis.io/rating/. Every facet and dimension name above is a link: it opens that measurement's own page — what it means, the exact checks that feed it, how the whole catalog distributes on it, and the providers at the top of it. This rating is computed from github.com/api-evangelist/mcp: open an issue to ask a question, or submit a pull request to add artifacts.
Submit an artifact on GitHub — free →Manage your own listing — the Influence plan, $499/mo →
The authoritative protocol definition for the Model Context Protocol, maintained at modelcontextprotocol.io and in the modelcontextprotocol/ specification GitHub repository. The...
Official TypeScript SDK published as @modelcontextprotocol/sdk on npm. Dual-purpose library for building MCP servers and clients on Node.js, Bun, and Deno. Supports Standard Sch...
Official Python SDK published as `mcp` on PyPI. Includes the FastMCP high-level framework with decorators for tools, resources, and prompts; low-level server primitives for prod...
Canonical collection of reference MCP server implementations maintained by the project. The active servers (Everything, Fetch, Filesystem, Git, Memory, Sequential Thinking, Time...
Developer tool for testing and debugging MCP servers. React-based web UI plus Node.js proxy, launched with `npx @modelcontextprotocol/inspector` and accessible at http://localho...
Community-driven, Anthropic-maintained registry that functions as an app store for MCP servers. Allows developers to publish server definitions and clients to discover them. Cur...
Third-party MCP server registry and hosted runtime. Catalogs community-built MCP servers, generates installation snippets for clients like Claude Desktop and Cursor, and can hos...
Third-party MCP directory and news site. Maintains a sub-registry API that implements the Generic MCP Registry API specification with PulseMCP-specific extensions for enriched m...
Anthropic's Claude Desktop application was the first MCP host. Connects to local MCP servers via stdio transport defined in claude_desktop_config .json and to remote servers via...
Cursor IDE supports MCP servers as a first-class extension mechanism, configured via mcp.json. Cursor is one of the most widely used MCP hosts for code-related workflows.
OpenAI's ChatGPT supports MCP through the Apps SDK and developer tooling documented at developers.openai.com, making MCP a cross-vendor surface for connecting tools and data to ...
MCP servers extend coding assistants like Cursor, VS Code Copilot, and Claude Code with project-aware tools, repository search, and terminal/build access.
Knowledge Base Access
MCP resources surface documentation, wikis, and structured data stores to AI hosts under user consent.
Workflow Automation
MCP tools let agents trigger build pipelines, send notifications, create tickets, and orchestrate multi-step business workflows.
Enterprise Connectors
Vendors expose enterprise systems (CRMs, ITSM, data warehouses) as MCP servers so that any MCP-aware host can connect without bespoke integration code.
Local Computer Use
Local MCP servers expose filesystem, git, shell, browser, and desktop automation tools to assistants running on the same machine.
modelcontextprotocol.io publishes the spec, schema, official SDKs for TypeScript, Python, Java, Kotlin, C#, Swift, and Rust, plus a set of reference servers and an Inspector deb...
Official Registry
The official MCP Registry is a central index of MCP servers with GitHub OAuth/OIDC and DNS-based ownership verification.
Third-Party Registries
Smithery and Pulse MCP provide alternative discovery surfaces and, in Smithery's case, hosted execution of community servers.
Vendor Hosts
Claude, ChatGPT, Cursor, VS Code Copilot, Continue, Cline, Zed, Windsurf, and many other assistants act as MCP hosts.
name: Model Context Protocol (MCP)
description: Model Context Protocol is an open, JSON-RPC 2.0 protocol from Anthropic that standardizes how AI applications
(hosts) connect to external systems via servers that expose tools, resources, and prompts. MCP is positioned as "a USB-C
port for AI applications" and has become the de-facto integration layer for Claude, ChatGPT, Cursor, Visual Studio Code,
and a growing ecosystem of agent runtimes. This topic repo catalogs the canonical specification, the official multi-language
SDKs, the reference server collection, community registries (Smithery, Pulse MCP, Naftiko Sandbox), and major MCP-aware
clients, plus the vocabulary, JSON Schema, JSON-LD, and example payloads needed to reason about the protocol.
url: https://github.com/api-evangelist/mcp
humanURL: https://modelcontextprotocol.io
deliveryModel:
model: unknown
open_source: unknown
commercial: false
callable_host: false
label: Delivery model not determined — needs a product licence on record
confidence: low
source:
- repository-unlicensed
generated: '2026-08-28'
method: derived
accessModel:
pricing: unknown
onboarding: unknown
trial: false
try_now: false
public: false
label: Unknown
confidence: low
source:
- security
generated: '2026-09-02'
method: derived
image: ''
tags:
- MCP
- AI Agents
- Tools
- Resources
- Prompts
- JSON-RPC
- Anthropic
- Standards
- Topic
tags_raw:
- Model Context Protocol
- MCP
- AI Agents
- Tools
- Resources
- Prompts
- JSON-RPC
- Anthropic
- Standards
- Topic
created: '2026-05-22'
modified: '2026-05-22'
specificationVersion: '0.23'
type: Index
apis:
- name: MCP Specification
description: The authoritative protocol definition for the Model Context Protocol, maintained at modelcontextprotocol.io
and in the modelcontextprotocol/ specification GitHub repository. The TypeScript schema (schema.ts) is the source of truth,
with an auto-generated JSON Schema (schema.json) for tooling. The current dated version is 2025-11-25. The protocol uses
JSON-RPC 2.0 messages between hosts, clients, and servers and defines tools, resources, prompts, sampling, roots, elicitation,
completion, and logging features.
humanURL: https://modelcontextprotocol.io/specification
baseURL: ''
tags:
- Specification
- JSON-RPC
- Schema
- Protocol
properties:
- type: Documentation
url: https://modelcontextprotocol.io/specification/2025-11-25
- type: GitHubRepository
url: https://github.com/modelcontextprotocol/specification
- type: JSONSchema
url: https://github.com/modelcontextprotocol/specification/blob/main/schema/2025-11-25/schema.json
- type: Versioning
url: https://modelcontextprotocol.io/specification/versioning
- name: MCP TypeScript SDK
description: Official TypeScript SDK published as @modelcontextprotocol/sdk on npm. Dual-purpose library for building MCP
servers and clients on Node.js, Bun, and Deno. Supports Standard Schema (Zod, Valibot, ArkType), stdio and Streamable
HTTP transports, and ships thin middleware adapters for Express, Hono, and Node HTTP. The v2 line is in development.
humanURL: https://github.com/modelcontextprotocol/typescript-sdk
tags:
- SDK
- TypeScript
- Node.js
properties:
- type: GitHubRepository
url: https://github.com/modelcontextprotocol/typescript-sdk
- type: SDKs
url: https://www.npmjs.com/package/@modelcontextprotocol/sdk
- name: MCP Python SDK
description: Official Python SDK published as `mcp` on PyPI. Includes the FastMCP high-level framework with decorators for
tools, resources, and prompts; low-level server primitives for production; client SDK; OAuth 2.1 resource-server support;
and stdio, SSE, and Streamable HTTP transports. Structured output is validated through Pydantic.
humanURL: https://github.com/modelcontextprotocol/python-sdk
tags:
- SDK
- Python
- FastMCP
properties:
- type: GitHubRepository
url: https://github.com/modelcontextprotocol/python-sdk
- type: SDKs
url: https://pypi.org/project/mcp/
- name: MCP Java SDK
description: Official Java SDK for building MCP servers and clients on the JVM. Maintained in the modelcontextprotocol/java-sdk
repository.
humanURL: https://github.com/modelcontextprotocol/java-sdk
tags:
- SDK
- Java
properties:
- type: GitHubRepository
url: https://github.com/modelcontextprotocol/java-sdk
- name: MCP Kotlin SDK
description: Official Kotlin SDK for MCP servers and clients targeting Kotlin and Android runtimes.
humanURL: https://github.com/modelcontextprotocol/kotlin-sdk
tags:
- SDK
- Kotlin
properties:
- type: GitHubRepository
url: https://github.com/modelcontextprotocol/kotlin-sdk
- name: MCP C# SDK
description: Official C# SDK for .NET, maintained in collaboration with Microsoft.
humanURL: https://github.com/modelcontextprotocol/csharp-sdk
tags:
- SDK
- C#
- .NET
tags_raw:
- SDK
- CSharp
- .NET
properties:
- type: GitHubRepository
url: https://github.com/modelcontextprotocol/csharp-sdk
- name: MCP Swift SDK
description: Official Swift SDK for MCP servers and clients on Apple platforms.
humanURL: https://github.com/modelcontextprotocol/swift-sdk
tags:
- SDK
- Swift
properties:
- type: GitHubRepository
url: https://github.com/modelcontextprotocol/swift-sdk
- name: MCP Rust SDK
description: Official Rust SDK for MCP servers and clients.
humanURL: https://github.com/modelcontextprotocol/rust-sdk
tags:
- SDK
- Rust
properties:
- type: GitHubRepository
url: https://github.com/modelcontextprotocol/rust-sdk
- name: MCP Reference Servers
description: Canonical collection of reference MCP server implementations maintained by the project. The active servers
(Everything, Fetch, Filesystem, Git, Memory, Sequential Thinking, Time) demonstrate every server-side feature of the protocol
and are recommended as the starting point for new implementers.
humanURL: https://github.com/modelcontextprotocol/servers
tags:
- Reference
- Servers
- Examples
properties:
- type: GitHubRepository
url: https://github.com/modelcontextprotocol/servers
- name: MCP Inspector
description: Developer tool for testing and debugging MCP servers. React-based web UI plus Node.js proxy, launched with
`npx @modelcontextprotocol/inspector` and accessible at http://localhost:6274. Provides interactive testing of tools,
resources, and prompts, plus a CLI mode for scripted testing.
humanURL: https://github.com/modelcontextprotocol/inspector
tags:
- Tooling
- Debugging
- Inspector
properties:
- type: GitHubRepository
url: https://github.com/modelcontextprotocol/inspector
- type: CLI
url: https://www.npmjs.com/package/@modelcontextprotocol/inspector
- name: Official MCP Registry
description: Community-driven, Anthropic-maintained registry that functions as an app store for MCP servers. Allows developers
to publish server definitions and clients to discover them. Currently in API freeze at v0.1. Supports GitHub OAuth, GitHub
OIDC, and DNS/HTTP ownership verification.
humanURL: https://registry.modelcontextprotocol.io
baseURL: https://registry.modelcontextprotocol.io
tags:
- Registry
- Discovery
properties:
- type: GitHubRepository
url: https://github.com/modelcontextprotocol/registry
- type: APIReference
url: https://registry.modelcontextprotocol.io/docs
- name: Smithery
description: Third-party MCP server registry and hosted runtime. Catalogs community-built MCP servers, generates installation
snippets for clients like Claude Desktop and Cursor, and can host servers on Smithery's infrastructure. Acts as a primary
discovery surface alongside the official registry.
humanURL: https://smithery.ai
tags:
- Registry
- Hosted
- Discovery
properties:
- type: Portal
url: https://smithery.ai
- name: Pulse MCP
description: Third-party MCP directory and news site. Maintains a sub-registry API that implements the Generic MCP Registry
API specification with PulseMCP-specific extensions for enriched metadata.
humanURL: https://www.pulsemcp.com
tags:
- Registry
- News
- Discovery
properties:
- type: Portal
url: https://www.pulsemcp.com
- type: APIReference
url: https://www.pulsemcp.com/api/docs/v0.1
- name: Claude Desktop (MCP Host)
description: Anthropic's Claude Desktop application was the first MCP host. Connects to local MCP servers via stdio transport
defined in claude_desktop_config .json and to remote servers via Streamable HTTP with OAuth 2.1.
humanURL: https://claude.com/docs/connectors/building
tags:
- Clients
- Hosts
- Claude
tags_raw:
- Client
- Host
- Claude
properties:
- type: Documentation
url: https://claude.com/docs/connectors/building
- name: Cursor (MCP Host)
description: Cursor IDE supports MCP servers as a first-class extension mechanism, configured via mcp.json. Cursor is one
of the most widely used MCP hosts for code-related workflows.
humanURL: https://cursor.com/docs/context/mcp
tags:
- Clients
- IDE
- Cursor
tags_raw:
- Client
- IDE
- Cursor
properties:
- type: Documentation
url: https://cursor.com/docs/context/mcp
- name: Visual Studio Code (MCP Host)
description: VS Code's GitHub Copilot Chat integrates MCP servers as agents and tools. Microsoft has standardized on MCP
for Copilot's agent-mode extensibility.
humanURL: https://code.visualstudio.com/docs/copilot/chat/mcp-servers
tags:
- Clients
- IDE
- VS Code
tags_raw:
- Client
- IDE
- VSCode
properties:
- type: Documentation
url: https://code.visualstudio.com/docs/copilot/chat/mcp-servers
- name: ChatGPT (MCP Host)
description: OpenAI's ChatGPT supports MCP through the Apps SDK and developer tooling documented at developers.openai.com,
making MCP a cross-vendor surface for connecting tools and data to ChatGPT.
humanURL: https://developers.openai.com/api/docs/mcp/
tags:
- Clients
- Hosts
- OpenAI
tags_raw:
- Client
- Host
- OpenAI
properties:
- type: Documentation
url: https://developers.openai.com/api/docs/mcp/
common:
- type: Website
url: https://modelcontextprotocol.io/
- type: IssueTracker
url: https://github.com/modelcontextprotocol/specification/issues
- type: Releases
url: https://github.com/modelcontextprotocol/specification/releases
- type: SecurityPolicy
url: https://github.com/modelcontextprotocol/modelcontextprotocol/blob/main/SECURITY.md
- type: CodeOfConduct
url: https://github.com/modelcontextprotocol/modelcontextprotocol/blob/main/CODE_OF_CONDUCT.md
- type: ContributionGuide
url: https://github.com/modelcontextprotocol/modelcontextprotocol/blob/main/CONTRIBUTING.md
- type: AgentCard
url: a2a/mcp-a2a.yml
name: A2A Agent Card
description: Agent Card served at /.well-known/agent-card.json (near-conformant against A2A 1.0.0).
- type: VulnerabilityDisclosure
url: security/mcp-vulnerability-disclosure.yml
- type: DomainSecurity
url: security/mcp-domain-security.yml
- type: Blog
url: https://blog.modelcontextprotocol.io/index.xml
- type: Portal
url: https://modelcontextprotocol.io
- type: Documentation
url: https://modelcontextprotocol.io/introduction
- type: GitHubOrganization
url: https://github.com/modelcontextprotocol
- type: GitHubRepository
url: https://github.com/modelcontextprotocol/specification
- type: Vocabulary
url: vocabulary/mcp-vocabulary.yml
- type: JSONLD
url: json-ld/mcp-context.jsonld
- type: Features
data:
- name: JSON-RPC 2.0 Base Protocol
description: MCP defines request, response, and notification message shapes on top of JSON-RPC 2.0 with strict rules on
IDs and structure.
- name: Stateful Sessions
description: Clients and servers negotiate capabilities during the initialize handshake and maintain stateful connections
for the lifetime of the session.
- name: Tools
description: Servers expose callable tools with JSON Schema 2020-12 input schemas; clients invoke them via tools/call.
- name: Resources
description: Servers expose URI-addressable context (files, database rows, API responses) via resources/list, resources/read,
and subscription notifications.
- name: Prompts
description: Servers expose templated prompts and workflows via prompts/list and prompts/get for users to invoke.
- name: Sampling
description: Clients can offer sampling/createMessage so servers can ask the host LLM to run agentic, recursive inference
under user consent.
- name: Roots
description: Clients can advertise filesystem roots that bound a server's operating scope via roots/list.
- name: Elicitation
description: Servers can request additional information from users mid-session via elicitation/create.
- name: Multiple Transports
description: MCP defines stdio for local processes and Streamable HTTP (with an optional SSE legacy mode) for networked
deployments.
- name: OAuth 2.1 Authorization
description: HTTP-based transports follow an MCP-defined OAuth 2.1 authorization framework; stdio transports retrieve
credentials from the environment.
- name: Icons and Branding
description: Implementations, tools, prompts, and resources can publish icon metadata for richer UIs, with strict security
constraints on icon URIs.
- name: Reserved _meta Namespace
description: MCP reserves the _meta property with a structured prefix/name format for attaching additional metadata to
interactions.
- type: UseCases
data:
- name: IDE Augmentation
description: MCP servers extend coding assistants like Cursor, VS Code Copilot, and Claude Code with project-aware tools,
repository search, and terminal/build access.
- name: Knowledge Base Access
description: MCP resources surface documentation, wikis, and structured data stores to AI hosts under user consent.
- name: Workflow Automation
description: MCP tools let agents trigger build pipelines, send notifications, create tickets, and orchestrate multi-step
business workflows.
- name: Enterprise Connectors
description: Vendors expose enterprise systems (CRMs, ITSM, data warehouses) as MCP servers so that any MCP-aware host
can connect without bespoke integration code.
- name: Local Computer Use
description: Local MCP servers expose filesystem, git, shell, browser, and desktop automation tools to assistants running
on the same machine.
- type: Integrations
data:
- name: Anthropic Claude
description: Claude Desktop, Claude Code, and the Claude API are first-class MCP hosts and are the protocol's reference
consumers.
- name: OpenAI ChatGPT
description: ChatGPT supports MCP through the Apps SDK and OpenAI's developer docs.
- name: Cursor
description: Cursor IDE consumes MCP servers via mcp.json configuration.
- name: Visual Studio Code
description: VS Code's Copilot Chat treats MCP servers as agents and tools.
- name: MCPJam
description: MCPJam is a community client implementation for testing MCP servers interactively.
- type: Solutions
data:
- name: Spec, SDKs, and Reference Servers
description: modelcontextprotocol.io publishes the spec, schema, official SDKs for TypeScript, Python, Java, Kotlin, C#,
Swift, and Rust, plus a set of reference servers and an Inspector debugging tool.
- name: Official Registry
description: The official MCP Registry is a central index of MCP servers with GitHub OAuth/OIDC and DNS-based ownership
verification.
- name: Third-Party Registries
description: Smithery and Pulse MCP provide alternative discovery surfaces and, in Smithery's case, hosted execution of
community servers.
- name: Vendor Hosts
description: Claude, ChatGPT, Cursor, VS Code Copilot, Continue, Cline, Zed, Windsurf, and many other assistants act as
MCP hosts.
maintainers:
- FN: Kin Lane
email: kinlane@gmail.com
url: http://kinlane.com
Discovery needs no key. Ratings and market analysis are Pro.
Get an API key
Free tier, no form to fill in. Signing in shares your email address with us — we
store it to create your key and to recognise you if you sign in with another
provider. See our Privacy Policy and
Terms.