Add expose_port previews with a Preview tab; leave setup to AGENTS.md

api/openapi.yaml

@@ -507,6 +507,24 @@ paths:
         "404": { $ref: "#/components/responses/Error" }
         "409": { $ref: "#/components/responses/Error" }
 
+  /api/tasks/{taskId}/previews:
+    parameters:
+      - { name: taskId, in: path, required: true, schema: { type: string } }
+    get:
+      operationId: listPreviews
+      description: >
+        The ports the task's agent exposed with expose_port, by name. Each is served by tailscale serve on the same
+        port number of byre's host, over HTTPS, until the task is merged or discarded.
+      responses:
+        "200":
+          description: The previews.
+          content:
+            application/json:
+              schema:
+                type: array
+                items: { $ref: "#/components/schemas/Preview" }
+        "404": { $ref: "#/components/responses/Error" }
+
   /api/tasks/{taskId}/snapshots:
     parameters:
       - { name: taskId, in: path, required: true, schema: { type: string } }
@@ -854,7 +872,7 @@ components:
         branch: { type: string }
         worktree_path: { type: string }
         base_ref: { type: string }
-        port_base: { type: integer, description: "The first of the task's block of ports (port_base to port_base+9), passed to its setup script and agent as PORT." }
+        port_base: { type: integer, description: "The first of the task's block of ports (port_base to port_base+9), passed to its agent and terminal as PORT." }
         status:
           type: string
           enum: [active, merged, discarded]
@@ -997,6 +1015,15 @@ components:
           description: "message: the agent wrote text after one or more tool calls; turn_end: after byre's end-of-turn commit. tool_call, ask_human and timer appear only on snapshots taken by earlier builds."
         created_at: { type: string, format: date-time }
 
+    Preview:
+      type: object
+      required: [task_id, name, port, created_at]
+      properties:
+        task_id: { type: string }
+        name: { type: string }
+        port: { type: integer, description: "A port in the task's block, served at https://<byre's host>:<port>/." }
+        created_at: { type: string, format: date-time }
+
     AgentSession:
       type: object
       required: [id, task_id, owner, vendor, model, vendor_session_id, state, role, created_by, created_at]
@@ -1179,8 +1206,8 @@ components:
 
     TaskTab:
       type: string
-      enum: [transcript, changes, files, terminal, inbox, project]
-      x-enum-varnames: [TabTranscript, TabChanges, TabFiles, TabTerminal, TabInbox, TabProject]
+      enum: [transcript, changes, files, terminal, preview, inbox, project]
+      x-enum-varnames: [TabTranscript, TabChanges, TabFiles, TabTerminal, TabPreview, TabInbox, TabProject]
 
     TerminalSize:
       type: object