Whether to use `unique_id` or `metadata.message_id` in cross-transfer API for pagination

[pratts]

Confirmation

• My issue isn't already found on the issue tracker.
• I have read the Subscan API documentation (if it seemed to be an API bug).

Affected Network(s)

Polkadot, Kusama

Steps to reproduce

1. Call the API for cross chain transfer (/api/scan/xcm/list) for a wallet.
2. Try to use the metadata.message_id field in the last transfer entity in after_id field for next api call for pagination.
3. In the API response for first call, the metadata field is not available, hence no parameter for pagination.

Expected output

1. Call the API for cross chain transfer (/api/scan/xcm/list) for a wallet.
2. Try to use the metadata.message_id field in the last transfer entity in after_id field for next api call for pagination.
3. In the API response for first call, the metadata field is available and I am able to paginate to next page based on after_id.

Actual output

1. Call the API for cross chain transfer (/api/scan/xcm/list) for a wallet.
2. Try to use the metadata.message_id field in the last transfer entity in after_id field for next api call for pagination.
3. In the API response for first call, the metadata field is available and I am able to paginate to next page based on after_id.

Additional factoids or references

There is one more field named unique_id in the cross-chain API response. It is shown as optional in the API doc.

1. Is is actually optional or always available in the response ?
2. Is it safe to use it to paginate based on after_id field in the API body ?

[freehere107]

Hi @pratts The after_id parameter is optional, as pagination can be achieved using page and row. However, for deep pagination—specifically when the dataset exceeds 10,000 records—the use of after_id becomes mandatory.

1. The after_id must correspond to the unique_id field provided in the response. Please note that the message_id within the metadata refers to the cross-chain transaction ID and is entirely unrelated to pagination logic.
2. Utilizing the after_id field within the API request body ensures a secure and robust pagination process.