yikart/AiToEarn · error · AppException

ChannelPaginationDirectionNotSupported

ChannelPaginationDirectionNotSupported

Error message

ChannelPaginationDirectionNotSupported

What it means

normalizeChannelPagination validates cursor-based pagination inputs against a platform's pagination metadata. When the caller asks for ChannelPaginationDirection.Previous but the platform's cursor metadata declares supportsPrevious=false, the helper throws ChannelPaginationDirectionNotSupported because that platform can only paginate forward. The thrown AppException carries the platform and requested direction in its details.

Source

Thrown at project/aitoearn-backend/apps/aitoearn-server/src/core/channels/platforms/platform-pagination.helper.ts:35

      expectedMode: metadata.mode,
      actualMode: normalizedMode,
    })
  }

  switch (normalizedMode) {
    case ChannelPaginationMode.Cursor: {
      const cursorMetadata = metadata as Extract<ChannelPaginationMetadata, { mode: ChannelPaginationMode.Cursor }>
      const limit = normalized.limit ?? cursorMetadata.defaultLimit
      if (limit > cursorMetadata.maxLimit) {
        throw new AppException(ResponseCode.ChannelPaginationLimitExceeded, {
          platform,
          limit,
          maxLimit: cursorMetadata.maxLimit,
        })
      }
      const direction = normalized.direction ?? ChannelPaginationDirection.Next
      if (direction === ChannelPaginationDirection.Previous && !cursorMetadata.supportsPrevious) {
        throw new AppException(ResponseCode.ChannelPaginationDirectionNotSupported, {
          platform,
          direction,
        })
      }
      return { ...normalized, limit, direction }
    }
    case ChannelPaginationMode.Page: {
      const pageMetadata = metadata as Extract<ChannelPaginationMetadata, { mode: ChannelPaginationMode.Page }>
      const pageSize = normalized.pageSize ?? pageMetadata.defaultPageSize
      if (pageSize > pageMetadata.maxPageSize) {
        throw new AppException(ResponseCode.ChannelPaginationPageSizeExceeded, {
          platform,
          pageSize,
          maxPageSize: pageMetadata.maxPageSize,
        })
      }
      return { page: normalized.page ?? 1, pageSize }
    }

View on GitHub (pinned to d3aa8bea5b)

Solutions

1. Check the platform's pagination metadata (cursorMetadata.supportsPrevious) before offering backward pagination, and hide/disable the 'previous' control when it is false.
2. Omit the direction field so it defaults to ChannelPaginationDirection.Next and paginate forward from the start.
3. Implement client-side backward navigation by keeping a stack of cursors and using the previous cursor with direction Next, instead of requesting direction Previous.
4. If the platform genuinely supports backward cursors, fix the integration registration so cursorMetadata.supportsPrevious is true.

Example fix

// before
await listComments(accountId, { cursor, direction: ChannelPaginationDirection.Previous })
// after
const meta = getPlatformPaginationMetadata(platform)
const direction = meta.mode === ChannelPaginationMode.Cursor && meta.supportsPrevious
  ? ChannelPaginationDirection.Previous
  : ChannelPaginationDirection.Next
await listComments(accountId, { cursor, direction })

const meta = platformPaginationMetadata[platform]
const canGoPrevious = meta?.mode === ChannelPaginationMode.Cursor && meta.supportsPrevious
if (requested.direction === ChannelPaginationDirection.Previous && !canGoPrevious) {
  // use Next or disable backward paging
}

function supportsPreviousPagination(meta: ChannelPaginationMetadata): meta is Extract<ChannelPaginationMetadata, { mode: ChannelPaginationMode.Cursor; supportsPrevious: true }> {
  return meta.mode === ChannelPaginationMode.Cursor && meta.supportsPrevious
}

try {
  return await listItems({ cursor, direction })
} catch (e) {
  if (e instanceof AppException && e.code === ResponseCode.ChannelPaginationDirectionNotSupported) {
    return await listItems({ cursor: previousCursorStack.pop(), direction: ChannelPaginationDirection.Next })
  }
  throw e
}

When it happens

Trigger: Calling any paginated channel listing API (works, comments, etc.) with direction: ChannelPaginationDirection.Previous (or 'previous' in the request body) for a platform whose ChannelPaginationMetadata has { mode: Cursor, supportsPrevious: false }. normalizeChannelPagination is invoked by input/normalizedPagination when a cursor or direction is present in the request.

Common situations: A frontend 'back to previous page' button applied to every platform; code shared across platforms where one platform (e.g. one that only offers forward cursors) rejects the backward navigation the other platforms support; reusing a saved 'Previous' direction from a different platform's list.

Related errors

• ChannelPaginationPageSizeExceeded
• No subtitle entries in response
• No response from Gemini
• Invalid subtitle data: ${z.prettifyError(result.error)}
• Canvas not provided and no vid:// video source found in Trac

AI-assisted analysis of yikart/AiToEarn@d3aa8bea5b (2026-08-31). Data as JSON: /api/errors/9b4ecaa726f6f7f0. Report an issue: GitHub.