Claude Code 2.1.275 request fails on advisor_20260301 tool

[cyberElar]

Claude Code request fails when advisor_20260301 is included in tools

Environment

• cc-switch-cli: 5.10.5
• Provider: DeepSeek
• Claude route: local proxy on 127.0.0.1:15721
• Claude Code using CC Switch local proxy through ANTHROPIC_BASE_URL

Problem

After a recent Claude Code update, requests through the CC Switch Claude proxy fail with:

API Error: 400 Failed to deserialize the JSON body into the target type:
tools[32]: unknown variant `advisor_20260301`,
expected `web_search_20250305` or `web_search_20260209`
at line 1 column 143873

The request body itself is valid JSON and is parsed successfully until the tools array is reached.

The new Claude Code version appears to include the Anthropic Advisor server tool:

{
  "type": "advisor_20260301"
}

The current Claude proxy or Anthropic compatibility layer appears to deserialize server tool types using an older schema that only recognizes:

web_search_20250305
web_search_20260209

Steps to reproduce

1. Configure Claude Code to use the CC Switch local proxy.
2. Select DeepSeek as the Claude provider in CC Switch.
3. Start a recent Claude Code version.
4. Send a simple prompt such as:

test

5. The request fails before model inference with the error above.

Expected behavior

CC Switch should either:

1. Support and correctly handle the advisor_20260301 Anthropic server tool, or
2. Strip or disable unsupported Anthropic server tools before forwarding to a provider that does not support them.

Actual behavior

The request is rejected during tool schema deserialization:

unknown variant `advisor_20260301`

Workaround

Disabling experimental Claude Code beta features avoids the issue:

export CLAUDE_CODE_DISABLE_EXPERIMENTAL_BETAS=1

This suggests the failure is specifically related to newly introduced Anthropic beta tools rather than the underlying DeepSeek request itself.

Notes

This looks like a compatibility issue introduced by newer Claude Code request schemas. CC Switch currently handles older Anthropic server tool variants, but the new Advisor tool is not accepted by the current conversion or deserialization path.