Share: og image

packages/function/src/api.ts

@@ -1,5 +1,6 @@
 import { DurableObject } from "cloudflare:workers"
 import { randomUUID } from "node:crypto"
+import { Base64 } from "js-base64"
 
 type Env = {
   SYNC_SERVER: DurableObjectNamespace<SyncServer>
@@ -180,8 +181,12 @@ export default {
         return new Response("Error: Share ID is required", { status: 400 })
       const stub = env.SYNC_SERVER.get(env.SYNC_SERVER.idFromName(id))
       const data = await stub.getData()
+
       let info
-      const messages = {}
+      const messages: Record<string, any> = {}
+      let cost = 0
+      const models: Set<string> = new Set()
+      const version = "v0.1.1"
       data.forEach((d) => {
         const [root, type, ...splits] = d.key.split("/")
         if (root !== "session") return
@@ -192,12 +197,36 @@ export default {
         if (type === "message") {
           const [, messageID] = splits
           messages[messageID] = d.content
+
+          const assistant = d.content.metadata?.assistant
+          if (assistant) {
+            cost += assistant.cost
+            models.add(assistant.modelID)
+          }
         }
       })
 
-      return new Response(JSON.stringify({ info, messages }), {
-        headers: { "Content-Type": "application/json" },
-      })
+      const encodedTitle = encodeURIComponent(
+        Base64.encode(
+          // Convert to ASCII
+          encodeURIComponent(
+            // Truncate to fit S3's max key size
+            info.title.substring(0, 700),
+          ),
+        ),
+      )
+      const encodedCost = encodeURIComponent(`$${cost.toFixed(2)}`)
+
+      return new Response(
+        JSON.stringify({
+          info,
+          messages,
+          ogImage: `https://social-cards.sst.dev/opencode-share/${encodedTitle}.png?cost=${encodedCost}&model=${Array.from(models).join(",")}&version=${version}&id=${id}`,
+        }),
+        {
+          headers: { "Content-Type": "application/json" },
+        },
+      )
     }
   },
 }