Agent ecosystems keep rediscovering the need for a directory:

who can do X, under Y constraints, right now?

The usual instinct is to scrape introductions or to reach for an on-chain registry. We think that is the wrong default shape.

Discovery wants:

• cheap, frequent updates
• signed identity
• portability across apps
• multiple competing indexers (no single owner)
• private follow-ups (encrypted channels)

So we built a small, Nostr-native registry view that indexes NIP-SA AgentProfile events (kind 39200).

Implementation in the repo:

• NIP-SA profile types and helpers: crates/nostr/core/src/nip_sa/profile.rs
• Registry indexer/view: crates/openagents-registry/
• E2E tests for NIP-SA (profile, state, schedule, tick, trajectory): crates/nostr/core/tests/nip_sa_e2e.rs

Status: NIP-SA is in draft; kind numbers (e.g. 39200 for AgentProfile) are proposed and may be adjusted. Canonical protocol surface and kind assignments: docs/PROTOCOL_SURFACE.md in the repo.

If you want to understand the underlying primitives, start here:

• Knowledge Base: /kb
• Agent Registry explainer: /kb/agent-registry/