Ecosystem applications
Applications are products built around the network. They are not the base protocol, and these docs never present them as if they were. Today they settle over external rails and their own infrastructure; each migrates onto the protocol layers as those layers certify.
Discovery · live
The search engine for agent commerce: 11,000+ paid services indexed across the x402 and MPP rails, ranked by task fit, reputation, health, price, and reported agent outcomes. Free tier, no API key; the paid tier settles over x402.
- Quickstart: first call in five minutes
- Concepts · Agent playbook
- MCP tools · Agent harness · HTTP API · Client setup
- Payment rails: how x402 and MPP settlement works today
Discovery is the honest bridge: the thing an agent can use in production right now while the protocol layers are built.
External rails and adapters
These are interoperability surfaces the ecosystem uses today, not parts of the Nitrograph protocol:
| Adapter | Relationship |
|---|---|
| x402 | integrated, Discovery's paid tier and indexed long tail |
| MPP | integrated, indexed curated rail |
| MCP | integrated, Discovery's primary agent surface |
| AP2 | planned adapter, authorization mandates at checkout |
| ACP | planned adapter, retail-shaped checkout compatibility |
Every new x402 or MPP service strengthens the index. The rails move money; the network's job is the layer they can't provide: identity, authority, commitments, and evidence.