Web Search

When using a web-search-enabled model, you can pass the web_search_options parameter to control how much search context is retrieved and processed. Models with this capability can dynamically integrate search results into their reasoning process.

There's a per-request fee applied by these models. Additionally, these models charge based on search context size, which controls how much data is retrieved and processed per query.

Web-Search Enabled Models

These models support built-in web search:

• openai/gpt-4o-mini-search-preview

• openai/gpt-4o-search-preview

• perplexity/sonar-pro

• perplexity/sonar-reasoning-pro

• perplexity/sonar

• perplexity/sonar-reasoning

Search Context Size

The search_context_size setting controls how much information is pulled from search results. Pricing may vary based on the selected level.

Level	Description	Use Case
low	Minimal context for basic queries	Quick facts, dates, headlines
medium	Moderate context with broader information coverage	General knowledge, short summaries
high	Extensive search context for deep research	In-depth topics, analysis, reports

Sample Request

This example uses openai/gpt-4o-mini-search-preview with medium search context to get real-time sports event info:

curl --location 'https://api.fastrouter.ai/api/v1/chat/completions' \
--header 'Content-Type: application/json' \
--header 'Authorization: Bearer API-KEY' \
--data '{
  "model": "openai/gpt-4o-mini-search-preview",
  "messages": [
    {
      "role": "user",
      "content": "Which teams are playing the UEFA Champions League final?"
    }
  ],
  "stream": false,
  "top_p": 1,
  "temperature": 0,
  "max_completion_tokens": 120,
  "web_search_options": {
    "search_context_size": "medium"
  }
}'

Enabling Web Search for Any Model

You can incorporate relevant web search results for any model on FastRouter by appending :online to the model slug:

{
  "model": "openai/gpt-oss-20b:online"
}

Pricing

The web plugin uses your FastRouter credits and charges $5 per 1000 answers.