I already have:

- dp_messages table with:
  - message_id
  - conversation_id
  - direction
  - channel
  - sender
  - message_body
  - template_key
  - mode
  - created_at

- insert_message() in app/db.py
- POST /api/messages in app/main.py

I now want to be able to fetch the message history for a conversation.

1) In app/db.py:

Add:

  async def fetch_messages_for_conversation(conversation_id: str, limit: int = 50):
      """
      Return the most recent messages for a conversation, ordered oldest → newest.
      """
      import uuid
      conv_uuid = uuid.UUID(conversation_id)
      conn = await get_conn()
      try:
          rows = await conn.fetch(
              """
              select message_id,
                     direction,
                     channel,
                     sender,
                     message_body,
                     template_key,
                     mode,
                     created_at
              from dp_messages
              where conversation_id = $1
              order by created_at asc
              limit $2
              """,
              conv_uuid,
              limit,
          )
          return [
              {
                  "message_id": str(r["message_id"]),
                  "direction": r["direction"],
                  "channel": r["channel"],
                  "sender": r["sender"],
                  "message_body": r["message_body"],
                  "template_key": r["template_key"],
                  "mode": r["mode"],
                  "created_at": r["created_at"].isoformat() if r["created_at"] else None,
              }
              for r in rows
          ]
      finally:
          await release_conn(conn)

2) In app/main.py:

- Import the helper:

  from app.db import fetch_messages_for_conversation

- Add a GET endpoint:

  @app.get("/api/messages")
  async def api_get_messages(
      conversation_id: str,
      limit: int = 50,
      user: dict = Depends(require_auth),
  ):
      """
      Return the latest messages for a conversation.
      """
      try:
          msgs = await fetch_messages_for_conversation(conversation_id, limit=limit)
      except Exception:
          logger.exception("Failed to fetch messages")
          return JSONResponse({"error": "Failed to fetch messages"}, status_code=500)

      return {
          "conversation_id": conversation_id,
          "messages": msgs,
      }

3) After implementing, restart the server and test:

- GET /api/messages?conversation_id=<valid_uuid>&limit=20
  Should return JSON with messages (if any).
- For a conversation with no messages, it should return an empty array for "messages".