> For clean Markdown of any page, append `.md` to the page URL.
> Documentation index: https://you.com/docs/llms.txt (section indexes: append `/llms.txt` to any section URL).
> Search these docs: Docs MCP at https://you.com/docs/_mcp/server (`searchDocs`, no API key).
> Call live You.com APIs: Product MCP at https://api.you.com/mcp (free Search only: `?profile=free`). To pick an API or integration path, call `you-discover` on that server instead of guessing.
> OpenAPI: https://you.com/docs/openapi.json—auth header `X-API-Key`, env `YDC_API_KEY`.

# Source Control

`source_control` lets you constrain which web sources the research agent searches and visits. Use it when you want results from trusted domains only, need to block specific sites, want recent content, or need results focused on a specific country.

`source_control` is a top-level request field alongside `input` and `research_effort`.

| Field             | Type       | Description                                                                                                                                                                                                                                                            |
| ----------------- | ---------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `include_domains` | `string[]` | Only return results from these domains. Max 500 domains. Cannot be used with `exclude_domains` or `boost_domains`.                                                                                                                                                     |
| `exclude_domains` | `string[]` | Never return results from these domains. Max 500 domains. Also blocks the research agent from visiting pages on those domains during browsing.                                                                                                                         |
| `boost_domains`   | `string[]` | Boost results from these domains without excluding other domains. Max 500 domains. Cannot be used with `include_domains`. Boosted domains are not guaranteed to appear in the final answer—the research agent may still select other sources if they are a better fit. |
| `freshness`       | `string`   | Filter results by recency. Accepts `day`, `week`, `month`, `year`, or a custom date range in `YYYY-MM-DDtoYYYY-MM-DD` format.                                                                                                                                          |
| `country`         | `string`   | ISO 3166-1 alpha-2 country code, such as `US`, `GB`, or `DE`, to geographically focus web results.                                                                                                                                                                     |

`include_domains` and `exclude_domains` cannot be used together in the same request. `boost_domains` can be combined with `exclude_domains`, but not with `include_domains`.

```curl
curl -X POST https://api.you.com/v1/research \
  -H "X-API-Key: $YDC_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "input": "What are the latest developments in quantum computing?",
    "research_effort": "deep",
    "source_control": {
      "include_domains": ["nature.com", "arxiv.org", "science.org"]
    }
  }'
```

You can also combine filters:

```curl
curl -X POST https://api.you.com/v1/research \
  -H "X-API-Key: $YDC_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "input": "New fintech regulations",
    "research_effort": "standard",
    "source_control": {
      "country": "GB",
      "freshness": "2026-01-01to2026-04-01"
    }
  }'
```

`source_control` and `output_schema` can be combined in a single request. See [Structured Output](/docs/guides/research/structured-output) for the combined example.

The Finance Research API does not support `source_control`. If you need domain filtering on financial questions, use the Research API.

[View full API reference](/docs/api-reference/research/v1-research)

## Next Steps

#### [Structured Output](/docs/guides/research/structured-output)

Return JSON that follows a schema, including combined with source control

#### [Research API Overview](/docs/guides/research)

Effort levels, how research works, and pricing

#### [API reference](/docs/api-reference/research/v1-research)

Full parameter reference and playground