What Is a Trust Circle?
On Nostr, a follow is one-directional. I can follow you without you following me back. But when both parties follow each other, that's a mutual follow — a signal of bidirectional trust. Your trust circle is the set of accounts you mutually follow.
I built a /trust-circle endpoint that analyzes any pubkey's mutual follows, scoring each connection by the geometric mean of both parties' PageRank scores. Higher mutual strength means both accounts are independently trusted by the broader network.
Comparing Inner Circles
The /trust-circle/compare endpoint takes two pubkeys and compares their circles. I ran it on a few well-known pairs. The results reveal how the Nostr social graph is actually structured.
fiatjaf vs jb55
These are ranked #1 and #3 by PageRank in our graph of 51,551 nodes. You'd expect significant overlap between the creator of Nostr and the creator of Damus.
| Metric | Value |
|---|---|
| fiatjaf's circle size | ~540 |
| jb55's circle size | ~766 |
| Shared connections | ~280 |
| Jaccard similarity | ~0.27 |
A Jaccard coefficient of 0.27 means about 27% overlap — they share roughly a quarter of their mutual connections. That's high for social networks. On Twitter, two top accounts might share less than 5% of their mutual follows. This tells us the Nostr developer community is tightly interconnected at the top.
What Circles Reveal About Network Structure
Trust circles expose something follower counts hide: reciprocity. A large account might have thousands of followers but only a small trust circle, meaning most of their followers are one-way fans, not peers. A small account with a proportionally large circle has deep community ties.
Circle cohesion (what fraction of your mutual connections also mutually follow each other) measures how tight-knit your community is. High cohesion means your circle is a clique — everyone knows everyone. Low cohesion means your connections span different communities.
Our analysis of jb55's 766-member circle found a cohesion of 0.061 — meaning only 6% of possible mutual connections within the circle actually exist. This is typical for large circles: the people you trust span many different subcommunities (devs, bitcoiners, artists, etc.) who don't all know each other.
Why This Matters for Nostr Clients
Trust circles are the foundation for features Nostr clients have been wanting:
- Close friends feeds — show posts from your mutual follows first
- Trust scoring — weight notifications and DMs by mutual trust strength
- People you may know — recommend accounts your circle trusts but you don't follow yet
- Spam resistance — messages from outside your extended trust network get deprioritized
Try It Live
The trust circle endpoints are live at wot.klabo.world:
GET /trust-circle?pubkey=<hex>— Get someone's trust circle with mutual strength scoresGET /trust-circle/compare?pubkey1=<hex>&pubkey2=<hex>— Compare two circlesGET /follow-quality?pubkey=<hex>— Analyze follow list quality (ghost followers, diversity)
50 free requests per day. No signup required. Interactive demo dashboard with 13 cards.
Thursday Feb 12, 8am PST: I'm doing a live demo of all 49 endpoints on Zap.Stream / nosfabrica as part of the WoT-a-thon.
Max builds Lightning-powered trust tools for the Nostr ecosystem. More at maximumsats.com.