deepseek-ai/deepseek-harness · error · WebError

WEB_PROVIDER_ERROR

WEB_PROVIDER_ERROR

Error message

DeepSeek returned no web_search_tool_result blocks; the request may not have triggered native web search

What it means

Error "DeepSeek returned no web_search_tool_result blocks; the request may not have triggered native web search" thrown in deepseek-ai/deepseek-harness.

Source

Thrown at packages/web/web-search-deepseek/src/provider.ts:151

/**
 * Map a DeepSeek Anthropic Messages response to a normalized search result. Walks
 * `web_search_tool_result` blocks for citeable `web_search_result` items, joins each to its
 * citation excerpt as `snippet`, and dedupes by `url` (a `max_uses > 1` request can surface
 * the same URL across searches). The web service owns the final `maxResults` truncation, so
 * `truncated` is always `false` here.
 *
 * @param response - the parsed Messages response body.
 * @returns the normalized result with deduped, snippet-joined sources.
 * @throws {@link WebError} when native search produced no result block.
 */
export function mapAnthropicResponse(response: AnthropicResponse): WebSearchResult {
  const blocks = response.content ?? []
  const resultBlocks = blocks.filter(
    (block): block is WebSearchToolResultBlock => block.type === 'web_search_tool_result',
  )
  if (resultBlocks.length === 0) {
    throw new WebError(
      'DeepSeek returned no web_search_tool_result blocks; the request may not have triggered native web search',
      'WEB_PROVIDER_ERROR',
    )
  }

  const snippets = citationSnippets(blocks)
  const seen = new Set<string>()
  const sources: WebSearchSource[] = []
  for (const block of resultBlocks) {
    for (const item of block.content ?? []) {
      if (item.type !== 'web_search_result' || item.url.length === 0 || seen.has(item.url)) continue
      seen.add(item.url)
      const snippet = snippets.get(item.url)
      sources.push({
        url: item.url,
        ...item.title != null && item.title.length > 0 ? { title: item.title } : {},
        ...snippet != null && snippet.length > 0 ? { snippet } : {},
        ...item.page_age != null && item.page_age.length > 0 ? { publishedAt: item.page_age } : {},

View on GitHub (pinned to b150a551b8)

Solutions

1. Rephrase the request so DeepSeek triggers native web search, or use a different search provider.

When it happens

Trigger: Thrown at packages/web/web-search-deepseek/src/provider.ts:151 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/e0ed0c2631b571de. Report an issue: GitHub.