add did-web example

src/config.ts

@@ -9,6 +9,7 @@ export type AppContext = {
 
 export type Config = {
   port: number
+  hostname: string
   sqliteLocation: string
   subscriptionEndpoint: string
   serviceDid: string

src/server.ts

@@ -7,6 +7,7 @@ import feedGeneration from './feed-generation'
 import { createDb, Database, migrateToLatest } from './db'
 import { FirehoseSubscription } from './subscription'
 import { AppContext, Config } from './config'
+import wellKnown from './well-known'
 
 export class FeedGenerator {
   public app: express.Application
@@ -30,6 +31,7 @@ export class FeedGenerator {
   static create(config?: Partial<Config>) {
     const cfg: Config = {
       port: config?.port ?? 3000,
+      hostname: config?.hostname ?? 'feed-generator.test',
       sqliteLocation: config?.sqliteLocation ?? ':memory:',
       subscriptionEndpoint: config?.subscriptionEndpoint ?? 'wss://bsky.social',
       serviceDid: config?.serviceDid ?? 'did:example:test',
@@ -59,6 +61,7 @@ export class FeedGenerator {
     }
     feedGeneration(server, ctx)
     app.use(server.xrpc.router)
+    app.use(wellKnown(cfg.hostname))
 
     return new FeedGenerator(app, db, firehose, cfg)
   }

src/well-known.ts

@@ -0,0 +1,22 @@
+import express from 'express'
+
+const makeRouter = (serverHostname: string) => {
+  const router = express.Router()
+
+  router.get('/.well-known/did.json', (_req, res) => {
+    res.json({
+      '@context': ['https://www.w3.org/ns/did/v1'],
+      id: `did:web:${serverHostname}`,
+      service: [
+        {
+          id: '#bsky_fg',
+          type: 'BskyFeedGenerator',
+          serviceEndpoint: `https://${serverHostname}`,
+        },
+      ],
+    })
+  })
+
+  return router
+}
+export default makeRouter