deepseek-ai/deepseek-harness · error · AttachmentError

IMAGE_TYPE_MISMATCH

IMAGE_TYPE_MISMATCH

Error message

Declared image type does not match its bytes.

What it means

Error "Declared image type does not match its bytes." thrown in deepseek-ai/deepseek-harness.

Source

Thrown at packages/attachment/attachment-local/src/store.ts:56

function objectPath(root: string, sha256: string): string {
  return join(root, 'objects', sha256.slice(0, 2), sha256)
}

function ensureReference(ref: ImageAttachmentRef): string {
  const match = ID_PATTERN.exec(String(ref.attachmentId))
  if (match?.[1] === undefined) throw new AttachmentError('Attachment reference is invalid.', 'INVALID_ATTACHMENT_REF')
  return match[1]
}

async function inspectMetadata(
  data: Uint8Array,
  declaredMediaType: ImageAttachmentRef['mediaType'],
  limits: ImageAttachmentLimits,
): Promise<DetectedImage> {
  if (data.byteLength === 0) throw new AttachmentError('Image is empty.', 'INVALID_IMAGE')
  const detected = await detectImage(data, { maxPixels: limits.maxImagePixels, maxDimension: limits.maxImageDimension })
  if (detected.mediaType !== declaredMediaType) throw new AttachmentError('Declared image type does not match its bytes.', 'IMAGE_TYPE_MISMATCH')
  return detected
}

/**
 * Run the full admission policy for one image without touching storage,
 * including normalization: a batch whose members all validate cannot later
 * be refused by the normalized image byte cap during publication.
 * @param input - encoded bytes and declared metadata.
 * @param limits - resolved source admission policy.
 * @param policy - resolved normalization policy.
 * @returns completion after the raster has been decoded and its normalized version proven to fit.
 */
export async function validateImageFile(
  input: SaveImageAttachment,
  limits: ImageAttachmentLimits,
  policy: NormalizationPolicy,
): Promise<void> {
  await prepareImageFile(input, limits, policy)

View on GitHub (pinned to b150a551b8)

Solutions

1. Declare the actual media type of the bytes, or supply bytes that match the declared type.

When it happens

Trigger: Thrown at packages/attachment/attachment-local/src/store.ts:56 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of deepseek-ai/deepseek-harness@b150a551b8 (2026-08-24). Data as JSON: /api/errors/3aaa9556393748b9. Report an issue: GitHub.