Add Web of Trust reputation on profiles via Vertex DVM

Query Vertex Verify Reputation API (kind 5312) for each profile and
display "Followed by people you trust" with clickable top-follower
avatars. Includes in-memory cache, request dedup, and graceful
fallback when logged out or API unreachable.

src/lib/nostr/index.ts

@@ -12,3 +12,5 @@ export type { AdvancedSearchResults } from "./search";
 export { fetchUserRelayList, publishRelayList, fetchRelayRecommendations } from "./relays";
 export type { UserRelayList } from "./relays";
 export { fetchTrendingCandidates, fetchTrendingHashtags } from "./trending";
+export { verifyReputation } from "./vertex";
+export type { ReputationResult, ReputationEntry } from "./vertex";

src/lib/nostr/vertex.ts

@@ -0,0 +1,77 @@
+import { fetch } from "@tauri-apps/plugin-http";
+import { NDKEvent } from "@nostr-dev-kit/ndk";
+import { getNDK } from "./core";
+import { debug } from "../debug";
+
+const VERTEX_API = "https://relay.vertexlab.io/api/v1/dvms";
+const VERTEX_TIMEOUT = 10000;
+
+export interface ReputationEntry {
+  pubkey: string;
+  rank: number;
+  follows?: number;
+  followers?: number;
+}
+
+export interface ReputationResult {
+  topFollowers: ReputationEntry[];
+  totalNodes: number;
+}
+
+/**
+ * Call Vertex Verify Reputation DVM (kind 5312).
+ * Returns personalized reputation data for a target pubkey.
+ */
+export async function verifyReputation(targetPubkey: string, limit = 7): Promise<ReputationResult | null> {
+  const ndk = getNDK();
+  if (!ndk.signer) return null;
+
+  try {
+    // Build and sign the DVM request event
+    const event = new NDKEvent(ndk);
+    event.kind = 5312;
+    event.content = "";
+    event.tags = [
+      ["param", "target", targetPubkey],
+      ["param", "limit", String(limit)],
+    ];
+    await event.sign();
+
+    const raw = event.rawEvent();
+    debug.log("vertex:verifyReputation", targetPubkey.slice(0, 8), "requesting...");
+
+    const resp = await fetch(VERTEX_API, {
+      method: "POST",
+      headers: { "Content-Type": "application/json" },
+      body: JSON.stringify(raw),
+      connectTimeout: VERTEX_TIMEOUT,
+    });
+
+    if (!resp.ok) {
+      debug.warn("vertex:verifyReputation HTTP", resp.status);
+      return null;
+    }
+
+    const responseEvent = await resp.json();
+
+    // Parse the kind 6312 response
+    if (responseEvent.kind === 7000) {
+      debug.warn("vertex:verifyReputation DVM error:", responseEvent.content);
+      return null;
+    }
+
+    const totalNodes = parseInt(
+      responseEvent.tags?.find((t: string[]) => t[0] === "nodes")?.[1] ?? "0",
+      10,
+    );
+
+    const topFollowers: ReputationEntry[] = JSON.parse(responseEvent.content || "[]");
+
+    debug.log("vertex:verifyReputation", targetPubkey.slice(0, 8), "→", topFollowers.length, "followers, nodes:", totalNodes);
+
+    return { topFollowers, totalNodes };
+  } catch (err) {
+    debug.warn("vertex:verifyReputation failed:", err);
+    return null;
+  }
+}