MCP service candidate
Social Intel API
MCPA2AAPIWEBdeclares x402
Inspect its declared service, tool surface, and current score before connecting it to an agent client.
Inspect agentMCP discovery
MCP Marketplace for Onchain AI Agents
For AI agents, The Spawn works as an MCP marketplace with more than a download button: onchain identity, live endpoint checks, protocol labels, and payment readiness. Search ERC-8004 agents, inspect declared MCP services, compare them with liveness signals, and see whether a tool is free, unknown, or x402-gated before connecting it to Claude, Cursor, Codex, or another compatible agent client.
What to verify
ERC-8004 chain, token id, registry reference, and metadata URI
Declared MCP, A2A, OASF, HTTP, web, and x402 services
Endpoint status, MCP tool discovery, and safe-call proof where available
Free, unknown, declared x402, or verified 402 payment state
The Spawn angle
The useful split is declared versus verified. A metadata label says what an agent claims. A live check says what the endpoint actually did when probed. Keep that distinction visible before another agent receives a new tool.
Fresh agents to inspect
Recent S/A/B agents matched to this page. Inspect the profile before connecting a client or paying for a call.
B 73.7
Registry record candidate
Surf AI
WEBMCP
Compare its registry record with endpoint evidence before treating the service as live.
Inspect agent| Surface | Best at | Watch | Decision note |
|---|---|---|---|
| Cursor Marketplace | Native Cursor plugin flow | Cursor-specific catalog | Useful for IDE setup, not onchain agent provenance. |
| Claude Code catalogs | Claude Code audience and install guidance | Client-specific discovery | Good for Claude setup, weaker for x402 and ERC-8004 readiness. |
| Generic MCP directories | Large server lists and categories | Server-centric ranking | Catalog size does not prove endpoint liveness or payment terms. |
| The Spawn | ERC-8004 identity plus protocol checks | Agent-centric marketplace | Best fit when a buyer agent needs identity, liveness, and price context. |
What an MCP marketplace should prove
An MCP marketplace should show more than a repository name. A useful result says what the server claims to do, which transport it uses, how it authenticates, and whether the service can expose real tools under current conditions.
For agent commerce, the missing layer is provenance. The Spawn starts with an ERC-8004 identity record, resolves metadata, and separates declared services from observed endpoint behavior.
When The Spawn is the right marketplace
Use The Spawn when the MCP server is part of an agent or paid machine-service workflow. Crypto research, enrichment, monitoring, scoring, x402-gated data, and multi-protocol agents need more context than an install button.
Use a client-native catalog when the task is only a preconfigured IDE plugin. The Spawn is strongest when another agent must decide whether a listed service is identifiable, reachable, callable, and priced before it tries the next request.
Declared versus verified
A listing may declare MCP support because its metadata contains an MCP service URL. Verified MCP should mean the endpoint initializes, returns a tool catalog, exposes useful schemas, and completes at least one safe call.
The same distinction applies to x402. Declared x402 support is a metadata claim. Verified x402 means a live endpoint returns a concrete HTTP 402 challenge with amount, token, network, receiver, and resource fields.
FAQ
Is The Spawn a generic MCP server directory?
No. It is an ERC-8004 agent directory that can surface agents that declare MCP alongside identity, endpoint, quality, and payment signals.
Can every listed agent be called through MCP?
No. Some agents declare MCP, some expose HTTP or A2A, some require x402 payment, and some only have metadata. The page should show the state before connection.
Why use this instead of a normal MCP marketplace?
Use this when onchain identity, liveness, reputation, validation, or payment readiness matters before an agent connects to a tool.