[FEATURE] Anthropic beta tools support - Web Search

Preflight Checklist

• [x] I have searched existing requests and this feature hasn't been requested yet
• [x] This is a single feature request (not multiple features)

Problem Statement

Anthropic Web Search is available on Vertex, if you add a header, example for Claude Code: ANTHROPIC_CUSTOM_HEADERS="anthropic-beta: web-search-2025-03-05" CLAUDE_CODE_USE_VERTEX=1 ANTHROPIC_VERTEX_PROJECT_ID=henri-cook-123...

It took me a while to learn this, I opened and closed a previous ticket in the mean time: https://github.com/anthropics/claude-code/issues/7806

Unfortunately because of the tool naming, it looks like Claude Code can't see and use this.

Proposed Solution

Feature Request: Allow me to tell Claude Code about, or have it discover, these uniquely Vertex based tools so that I can use Anthropic Web Search from Claude Code on Vertex.

Here's an example of using the Vertex Web Search API that I've verified works (as code like this, not in Claude Code), that was provided by Google Support as an example for me.

<img width="851" height="506" alt="Image" src="https://github.com/user-attachments/assets/362a6c2f-11db-4958-af0f-b1e8c13fee91" />

Alternative Solutions

• I thought about writing an MCP server but passing all the Vertex credentials that Claude Code is using so that it can run searches in the same project didn't seem like a secure choice.

Priority

High - Significant impact on productivity

Feature Category

API and model interactions

Use Case Example

1. As someone using Claude Code with Vertex, I'd like to be able to do a Web Search
2. At the moment I can connect various MCP servers e.g. Tavily
3. But I'd like to be able to use the Vertex/Anthropic 'supported options'

AIUI this leads to more revenue for Anthropic because we'll be using your search service instead of a competitor like Tavily, so I'm assuming it's something you'd like to do.

We're more confident in the data security of using this 'first class' Vertex solution Vs. other providers.

Additional Context

_No response_