web-fetch-tool changedagents-and-tools/tool-use/web-fetch-tool
Nearest release: v2.1.318, published 4 hours before this site recorded the change. Shown because the two are within 24 hours of each other. Nothing here says the release caused the edit.
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4141
4242The web fetch tool allows Claude to retrieve full content from specified webpages and PDF documents.
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44The latest web fetch tool version (`web_fetch_20260318`) supports **dynamic filtering**: Claude can write and execute code to filter fetched content before it reaches the context window, keeping only relevant information and discarding the rest. This reduces token consumption while maintaining response quality. Dynamic filtering is available with Claude 4.6 and later models and [Claude Mythos Preview](https://anthropic.com/glasswing). `web_fetch_20260318` also adds [response inclusion](https://platform.claude.com/docs/en/agents-and-tools/tool-use/web-fetch-tool#response-inclusion) control for agentic workflows. The previous versions (`web_fetch_20260309` for dynamic filtering and [cache bypass](https://platform.claude.com/docs/en/agents-and-tools/tool-use/web-fetch-tool#cache-bypass), `web_fetch_20260209` for dynamic filtering only, `web_fetch_20250910` for basic fetch) remain available.
44The latest web fetch tool version (`web_fetch_20260318`) supports **dynamic filtering**: Claude can write and run code to filter fetched content before it reaches the context window, keeping only relevant information and discarding the rest. This reduces token consumption while maintaining response quality. Dynamic filtering is available with Claude 4.6 and later models and [Claude Mythos Preview](https://anthropic.com/glasswing). `web_fetch_20260318` also adds [response inclusion](https://platform.claude.com/docs/en/agents-and-tools/tool-use/web-fetch-tool#response-inclusion) control for agentic workflows. The other versions (`web_fetch_20260309` for dynamic filtering and [cache bypass](https://platform.claude.com/docs/en/agents-and-tools/tool-use/web-fetch-tool#cache-bypass), `web_fetch_20260209` for dynamic filtering only, `web_fetch_20250910` for basic fetch) are available.
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4646Web fetch (with and without dynamic filtering) is available on the Claude API, [Claude Platform on AWS](https://platform.claude.com/docs/en/build-with-claude/claude-platform-on-aws), [Claude Models on Google Cloud (Anthropic managed)](https://platform.claude.com/docs/en/build-with-claude/claude-models-on-google-cloud/anthropic-managed), and [Microsoft Foundry](https://platform.claude.com/docs/en/build-with-claude/claude-in-microsoft-foundry). On Microsoft Foundry, deployments [hosted on Azure](https://platform.claude.com/docs/en/build-with-claude/claude-in-microsoft-foundry#additional-features-not-supported-when-hosted-on-azure) support only the basic web fetch tool (`web_fetch_20250910`, without dynamic filtering). Deployments hosted on Anthropic support all versions.
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from line 117
117117 ```bash cURL
118118 curl https://api.anthropic.com/v1/messages \
119119 -H "x-api-key: $ANTHROPIC_API_KEY" \
120 -H "anthropic-version: 2023-06-01" \
120 -H "anthropic-version: 2026-10-21" \
121121 -H "content-type: application/json" \
122122 -d '{
123123 "model": "claude-opus-5-5",
from line 287
287287 ```bash cURL
288288 curl https://api.anthropic.com/v1/messages \
289289 -H "x-api-key: $ANTHROPIC_API_KEY" \
290 -H "anthropic-version: 2023-06-01" \
290 -H "anthropic-version: 2026-10-21" \
291291 -H "content-type: application/json" \
292292 -d '{
293293 "model": "claude-opus-5-5",
from line 752
752752 ```bash cURL
753753 curl https://api.anthropic.com/v1/messages \
754754 -H "x-api-key: $ANTHROPIC_API_KEY" \
755 -H "anthropic-version: 2023-06-01" \
755 -H "anthropic-version: 2026-10-21" \
756756 -H "content-type: application/json" \
757757 -d '{
758758 "model": "claude-opus-5-5",
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