Add web fetch tool support for Anthropic

[Shulyaka]

Proposed change

Add web fetch server tool support for Anthropic

Type of change

• Dependency upgrade
• Bugfix (non-breaking change which fixes an issue)
• New integration (thank you!)
• New feature (which adds functionality to an existing integration)
• Deprecation (breaking change to happen in the future)
• Breaking change (fix/feature causing existing functionality to break)
• Code quality improvements to existing code or addition of tests

Additional information

• This PR fixes or closes issue:
• This PR is related to issue:
• Link to documentation pull request: Add web fetch tool support for Anthropic home-assistant.io#44502
• Link to developer documentation pull request:
• Link to frontend pull request:

Checklist

• I understand the code I am submitting and can explain how it works.
• The code change is tested and works locally.
• Local tests pass. Your PR cannot be merged unless tests pass
• There is no commented out code in this PR.
• I have followed the development checklist
• I have followed the perfect PR recommendations
• The code has been formatted using Ruff (ruff format homeassistant tests)
• Tests have been added to verify that the new code works.
• Any generated code has been carefully reviewed for correctness and compliance with project standards.

If user exposed functionality or configuration variables are added/changed:

• Documentation added/updated for www.home-assistant.io

If the code communicates with devices, web services, or third-party tools:

• The manifest file has all fields filled out correctly.
  Updated and included derived files by running: python3 -m script.hassfest.
• New or updated dependencies have been added to requirements_all.txt.
  Updated by running python3 -m script.gen_requirements_all.
• For the updated dependencies a diff between library versions and ideally a link to the changelog/release notes is added to the PR description.

To help with the load of incoming pull requests:

• I have reviewed two other open pull requests in this repository.

[Copilot]

Pull request overview

This PR adds support for Anthropic’s web fetch server tool to the Anthropic conversation agent, including configuration options, runtime tool wiring, and tests/snapshots to validate the new behavior.

Changes:

• Add new config options (web_fetch, web_fetch_max_uses) to the subentry config flow and UI strings.
• Implement web fetch tool handling in the Anthropic conversation entity (tool selection + tool result conversion).
• Add test coverage and update snapshots for web fetch success and error cases.

Reviewed changes

Copilot reviewed 8 out of 8 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
homeassistant/components/anthropic/entity.py	Adds web fetch tool support (tool selection + stream/tool-result conversion) and broadens citation serialization.
homeassistant/components/anthropic/config_flow.py	Exposes web fetch options in the model options step and validates numeric inputs as positive ints.
homeassistant/components/anthropic/const.py	Introduces new constants/defaults for web fetch configuration.
homeassistant/components/anthropic/strings.json	Adds UI labels and descriptions for web fetch settings (conversation + AI task subentries).
tests/components/anthropic/__init__.py	Adds a helper to generate streamed web fetch tool result blocks for tests.
tests/components/anthropic/test_conversation.py	Adds new conversation tests covering web fetch success and error flows.
tests/components/anthropic/test_config_flow.py	Updates config flow tests to include the new web fetch options in expected data.
tests/components/anthropic/snapshots/test_conversation.ambr	Adds/updates snapshots for web fetch-related conversation flows and history conversion.

[Copilot]

Pull request overview

Copilot reviewed 8 out of 8 changed files in this pull request and generated no new comments.

[Copilot]

Pull request overview

Copilot reviewed 8 out of 8 changed files in this pull request and generated 1 comment.

[Copilot]

Pull request overview

Copilot reviewed 8 out of 8 changed files in this pull request and generated no new comments.

[Copilot]

Pull request overview

Copilot reviewed 8 out of 8 changed files in this pull request and generated no new comments.

[Copilot]

Pull request overview

Copilot reviewed 8 out of 8 changed files in this pull request and generated no new comments.

[Copilot]

Pull request overview

Copilot reviewed 8 out of 8 changed files in this pull request and generated 2 comments.

[Copilot]

Pull request overview

Copilot reviewed 8 out of 8 changed files in this pull request and generated no new comments.

[zweckj]

there are merge conflicts, could you take a look?

[Copilot]

Pull request overview

Copilot reviewed 8 out of 8 changed files in this pull request and generated no new comments.

[Shulyaka]

Done!