- Array order is display order; item 1 is the cover.
- An active Tencent COS configuration is required. URLs on its configured public/CDN origin are reused; other public images are downloaded, validated, and stored in that COS before the work is created.
- Cross-origin images must be supported image responses no larger than 20 MB. Local, private, reserved, and non-standard-port targets are rejected.
- Repeating the same `projectId + externalId` returns the existing work with `idempotent: true`.
Local-file mode uses `multipart/form-data` with text fields `externalId`, `title`, `description`, `tags` and repeated file field `images`.
- Send `tags` as a JSON array string.
- Send 1-30 JPEG, PNG, GIF, WebP, or AVIF files, each no larger than 20 MB.
- File order is display order; file 1 is the cover.
- The server validates actual image content instead of trusting only the filename or declared MIME.
- With active Tencent COS configuration, accepted files are streamed from server temporary storage into COS.
- Do not send Base64 in JSON. The agent script reads local files directly into the multipart request; binary bytes never belong in the plan or conversation.
| `400` | `revise` | Correct malformed input, regenerate the plan, and obtain a new confirmation. |
| `401` | `ask_operator` | Ask the operator to configure or replace `DELIVERY_DESK_API_KEY`. |
| `403` | `ask_operator` | Report the exact group/project and ask an administrator to correct Key scope. Never select another target. |
| `404` | `ask_operator` | Re-run read-only discovery, then ask the operator if the confirmed target is gone or inaccessible. |
| `409` | `ask_operator` | Report the target state and wait for the operator or administrator to resolve it. |
| `413` | `revise` | Replace or reduce the image, regenerate the plan, and obtain a new confirmation. |
| `422` | `revise` | Replace the unreachable or unsupported public image URL, regenerate the plan, and obtain a new confirmation. |
| `502` | `ask_operator` for writes | Do not retry the write automatically; inspect state and ask the operator to check Tencent COS. |
| `429`, `503`, `504` | `retry` for reads only | Wait and retry the same read-only command without changing the target. Writes require `ask_operator`. |
Do not work around `403` or `409` by selecting a different project. Report the exact target and ask the operator or administrator to resolve access/state.