Two of the four grounded web-search adapters default to their vendor's flagship tier — 5x and 6.7x the cheapest sibling, undocumented

[sroussey]

What

The four grounded ./web-search adapters that shipped this window each pick a default model, and the four choices are not made on one principle:

$ grep -n "DEFAULT_MODEL = " providers/*/src/web-search/*.ts
providers/anthropic/src/web-search/AnthropicWebSearchProvider.ts:25:const DEFAULT_MODEL = "claude-opus-5";
providers/google-gemini/src/web-search/GeminiWebSearchProvider.ts:21:const DEFAULT_MODEL = "gemini-3.6-flash";
providers/openai/src/web-search/OpenAiWebSearchProvider.ts:20:const DEFAULT_MODEL = "gpt-5.5";
providers/openrouter/src/web-search/OpenRouterWebSearchProvider.ts:21:const DEFAULT_MODEL = "openai/gpt-5.2";

Priced off each package's own rate table (USD per 1M tokens, read from Anthropic_Pricing.ts and OpenAI_Pricing.ts at 2d36880):

adapter	default	in / out	cheapest capable sibling in the same table	ratio
anthropic	claude-opus-5	5 / 25	claude-haiku-4-5 — 1 / 5	5.0x in, 5.0x out
openai	gpt-5.5	5 / 30	gpt-5.4-mini — 0.75 / 4.5	6.7x in, 6.7x out
openrouter	openai/gpt-5.2	2.5 / 10	—	mid tier
gemini	gemini-3.6-flash	flash tier	—	cheap tier

A concrete search — ~2,000 prompt tokens (query + tool results) and ~800 output tokens — costs $0.030 on claude-opus-5 against $0.006 on claude-haiku-4-5, for a task whose job is to retrieve citations and summarise them.

Why it matters

1. register<Vendor>WebSearchProvider() with no options is the documented call. providers/<vendor>/src/web-search.ts takes options: XWebSearchOptions = {}, and the package CLAUDE.md's registration guidance shows it bare. The default is therefore what most hosts will actually run.
2. "auto" routing makes it worse. WebSearchTask's provider: "auto" picks by capability, not price. All four declare answer: true and content: false; anthropic and openai additionally declare domainFilter: "native". So a plain keyword search with a site: restriction can land on claude-opus-5 with nothing in the request that says so.
3. Nothing documents it. None of the four provider READMEs mentions ./web-search at all:

   $ grep -ril "web-search\|web search" providers/*/README.md
   (nothing)
   

   providers/openrouter/README.md is 9 lines total.
4. The other two adapters chose the cheap tier, so this is not a considered house style — it is four independent choices.

Proposed fix

1. Default to the cheapest model in each family that carries the server-side search tool — claude-haiku-4-5 and a gpt-5.*-mini, matching what gemini and openrouter already did. Grounding is retrieval; the synthesis is a paragraph.
2. Say it in the adapter, beside the constant, the way the rest of these files argue their choices (AnthropicWebSearchProvider.ts:61-71 is the model): "the default is the cheapest id that carries web_search; a caller wanting the flagship passes model."
3. Document the default and its rate in the provider README, together with the fact that the subpath exists — see Zero of 25 provider READMEs document any of the four cross-provider primitives, and four providers have had no README for eight cycles #911, which this makes worse (the ./web-search subpath is a fifth undocumented cross-provider surface).
4. Optionally, a one-line assertion in each package's existing co-located test file that new XWebSearchProvider({}).model equals the intended cheap id, so a bump is a decision someone writes down.

Found during the 2026-09-14 review of providers/. Verified against origin/main @ 2d36880.