deepseek-ai/deepseek-harness · error

no attachment store is mounted

Error message

no attachment store is mounted

What it means

Error "no attachment store is mounted" thrown in deepseek-ai/deepseek-harness.

Source

Thrown at packages/mcp/mcp-client/src/tools.ts:401

  if (block.data === undefined || !CANONICAL_BASE64.test(block.data)) {
    throw new Error('the image data is not canonical base64')
  }
  const data = Buffer.from(block.data, 'base64')
  if (data.toString('base64') !== block.data) {
    throw new Error('the image data is not canonical base64')
  }
  return { data, mediaType: block.mimeType }
}

/**
 * Resolve the active model route and durable store for an image-bearing result.
 * @param ctx - plugin context with optional services.
 * @param exec - exact tool execution whose agent supplies the latest route.
 * @returns the attachment store after exact positive image-capability proof.
 */
async function resolveImageAdmission(ctx: Context, exec: ToolExecution): Promise<AttachmentStore> {
  const attachments = ctx.get('attachments')
  if (attachments === undefined) throw new Error('no attachment store is mounted')
  const routed = exec.agent?.session.requestHeader()?.config
  const provider = routed?.provider ?? exec.agent?.options.provider
  const model = routed?.model ?? exec.agent?.options.model
  const llm = ctx.get('llm')
  if (provider === undefined || model === undefined || llm === undefined) {
    throw new Error('the current model route could not be resolved')
  }
  let info: Awaited<ReturnType<typeof llm.resolveModelInfo>>
  try {
    info = await llm.resolveModelInfo(provider, model, exec.signal)
  } catch {
    throw new Error('the current model route could not be verified')
  }
  if (info.inputModalities === undefined || !info.inputModalities.includes('image')) {
    throw new Error(`model "${model}" does not declare image input`)
  }
  if (exec.signal.aborted) throw new Error('the tool call was canceled before image storage')
  return attachments

View on GitHub (pinned to b150a551b8)

Solutions

1. Mount an attachment store in the composition.

When it happens

Trigger: Thrown at packages/mcp/mcp-client/src/tools.ts:401 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/e3771ccb62588991. Report an issue: GitHub.