Kaede AkinoandClaude Opus 5
c1af3a189f
Whether an endpoint really runs web search on its own servers is inferred from the model id, and a gateway can make that inference wrong in either direction. Both directions turned up within a day of shipping it: an OpenAI-shaped `/responses` proxy in front of Claude got a server tool it forwards as an ordinary function, and DeepSeek's Anthropic-shaped endpoint — which does implement the tool — got refused for not being Claude. A guess that fails both ways needs a switch, so Web Search grows one. On by default; off sends every model through the backend, which behaves the same on every endpoint. The switch made it worth separating the two questions that were tangled together. Whether the protocol has anywhere to *put* a server tool is a hard fact about the request body — Chat Completions does not, and no setting overrides that, because overriding it yields a request with no search tool of any kind. Whether the endpoint runs search *for this model* is the guess. They now have separate names. DeepSeek is also a first party on the Anthropic shape. Its `/anthropic` guide lists `server_tool_use` and `web_search_tool_result` as supported content blocks while marking `code_execution_tool_result` and `mcp_tool_use` unsupported in the same table, so that list is real rather than copied from Anthropic's. The family rule was reading "not Anthropic's own model" as "no native search", which refused a pairing that works. It is about implementation, not branding. The tool *declaration* name is the one thing that page does not document; sending Anthropic's `web_search_20250305` is an assumption, and an unverified one. `DuckDuckGo` gains the `(Local)` suffix `Bing` already had. Both are the same thing — a browser-shaped request whose answer is a page Termind parses itself — so marking one and not the other was distinguishing nothing. Applied to both it separates the two backends that have no key and no contract from the three that do. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>