MCP Overview
Agent Explorer supports the Model Context Protocol (MCP) alongside the A2A protocol. MCP defines a standard way for AI models to access external tools, resources, and prompts via a JSON-RPC 2.0 interface.
What Is MCP?
MCP (Model Context Protocol) is an open standard that enables AI applications to connect to external capabilities:
- Tools — Functions the AI can call (e.g., search the web, query a database, run code)
- Resources — Data sources the AI can read (e.g., files, database records, live feeds)
- Prompts — Pre-defined prompt templates parameterised by the client
Transport
Agent Explorer supports the Streamable HTTP MCP transport — the primary HTTP transport in the MCP specification. Stdio-based MCP servers (common for local tools) require a proxy layer to expose an HTTP endpoint before Agent Explorer can connect to them.
How Agent Explorer Supports MCP
Real MCP Servers
Connect to any Streamable HTTP MCP server to:
- Browse all available tools, resources, and prompts
- Invoke capabilities directly with a structured form UI
- Authenticate via MCP OAuth 2.1 with PKCE
See Real MCP Playground for full details.
Mock MCP Servers
Create fully configurable mock MCP servers to:
- Develop clients before the real server exists
- Simulate specific tool responses using the Flow Builder
- Test error handling and latency scenarios
See Mock MCP Studio for full details.
MCP vs A2A
| Aspect | MCP | A2A |
|---|---|---|
| Primary purpose | Tool/resource access for AI models | Agent-to-agent coordination |
| Communication | Client → Server (synchronous RPC) | Agent ↔ Agent (async tasks) |
| State model | Stateless capability calls | Stateful tasks with lifecycle |
| Discovery | Capability manifest (tools/list etc.) | AgentCard (.well-known) |
| Auth | OAuth 2.1 + PKCE (RFC 9728 PRM) | OAuth 2.0 or API key |
Explorer Page
MCP servers live alongside A2A agents on the Explorer page (/explorer). The three-column layout shows:
- Workspaces — groups that can contain both agents and MCP servers
- Agents — A2A agent connections
- MCP Servers — real and mock MCP server connections
Use the Add New dropdown (top-right of the Explorer) to create a new Workspace, Agent, or MCP Server. In team contexts a separate Add Existing dropdown lets you import resources that already exist.