> 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 (keyless `?profile=free` exposes `you-search` and `you-discover`. Research and finance use `/mcp/research`, `/mcp/finance`, or `?tools=` on `/mcp`). 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`.

# Choose the Right API

Pick the card that matches what your code needs back. Every API takes the same `X-API-Key` header, so switching later is a URL and payload change.

## Match the Job

#### [Ranked web and news results](/docs/guides/search)

**Web Search API.** JSON results for your own model, RAG pipeline, or UI. \$5.00 per 1,000 calls.

#### [Page text from URLs you have](/docs/guides/contents)

**Contents API.** Markdown or HTML for known URLs, no search step. \$1.00 per 1,000 pages.

#### [A cited answer, fast](/docs/guides/answer)

**Answer API.** One search pass, a Markdown answer, and verbatim excerpts you can audit. p50 2.67s.

#### [A researched answer with depth control](/docs/guides/research)

**Research API.** Multiple searches, `lite` through `frontier` effort, and optional structured JSON.

#### [A cited answer about markets or companies](/docs/guides/finance-research)

**Finance Research API.** The Research API response shape over a finance-optimized index.

#### [Tools for an agent or IDE](/docs/agents)

**MCP Server.** Claude Code, Cursor, and other MCP clients call search, contents, and research as tools.

## Compare the Five APIs

| API                                                   | Use it for                                                            | Returns                                                                        | Latency                                                                  | Price                                                                                          |
| ----------------------------------------------------- | --------------------------------------------------------------------- | ------------------------------------------------------------------------------ | ------------------------------------------------------------------------ | ---------------------------------------------------------------------------------------------- |
| [Web Search API](/docs/guides/search)                 | Ranked web and news results for your own model, RAG pipeline, or UI   | JSON results. Snippets by default, or highlights or full page via `extraction` | Retrieval only, no synthesis step, so it returns ahead of the Answer API | \$5.00 / 1k calls, up to 100 results per call. Full page add-on \$1.00 / 1k pages fetched live |
| [Contents API](/docs/guides/contents)                 | Page text from URLs you already have                                  | Markdown, HTML, metadata, or any combination                                   | Up to `crawl_timeout` per URL (default 10s). Cached pages return sooner  | \$1.00 / 1k pages                                                                              |
| [Answer API](/docs/guides/answer)                     | A cited answer from one search pass                                   | Markdown answer, citations with verbatim excerpts, and web results             | p50 2.67s                                                                | \$5.00 / 1k calls                                                                              |
| [Research API](/docs/guides/research)                 | Multi-step cited answers with depth control                           | Markdown or structured JSON, plus sources                                      | \< 10s (`lite`) through background-only (`frontier`)                     | \$12 / 1k (`lite`) through \$1,200 / 1k (`frontier`)                                           |
| [Finance Research API](/docs/guides/finance-research) | Cited answers about filings, prices, fundamentals, and financial news | Markdown answer plus sources                                                   | \< 120s (`deep`) or \< 300s (`exhaustive`)                               | \$110 / 1k (`deep`) or \$500 / 1k (`exhaustive`)                                               |

Pricing is pay-as-you-go, and new accounts start with \$100 in credits. [Billing](/docs/administration/billing) has the full tables, including how cached pages change the full page charge.

## Latency and Price by Effort Tier

The Research API and Finance Research API trade latency for depth through `research_effort`. Pick the lowest tier that answers the question.

#### Research API

| Tier         | Price per 1k | Latency                                 | Use case                                                       |
| ------------ | ------------ | --------------------------------------- | -------------------------------------------------------------- |
| `lite`       | \$12         | \< 10s                                  | Quick factual lookups, simple searches                         |
| `standard`   | \$50         | \~10–30s                                | Balanced depth for most production use (default)               |
| `deep`       | \$100        | \< 120s                                 | Complex multi-source research and synthesis                    |
| `exhaustive` | \$450        | \< 300s                                 | Comprehensive analysis across dozens of sources                |
| `frontier`   | \$1,200      | Background only. 30s–12000s (p50: 300s) | Long-running deep research tasks. Requires `background: true`. |

A synchronous request holds the connection for the full run. Set your HTTP client timeout above the tier's upper bound—longer than 120s for `deep` and 300s for `exhaustive`—or send `background: true` and collect the result with [background requests](/docs/guides/research/background-requests).

#### Finance Research API

| Tier         | Price per 1k | Latency | Use case                                                                                                                |
| ------------ | ------------ | ------- | ----------------------------------------------------------------------------------------------------------------------- |
| `deep`       | \$110        | \< 120s | Multi-source analysis—earnings summaries, competitive benchmarking, regulatory research, multi-quarter trends (default) |
| `exhaustive` | \$500        | \< 300s | Comprehensive research—deep due diligence, full 10-K analysis, cross-market research                                    |

The Finance Research API has no background mode, so every request holds the connection until the answer is ready. Set your HTTP client timeout longer than 120s for `deep` and 300s for `exhaustive`.

## Details That Change the Choice

#### Web Search API: snippets, highlights, or full page

Results carry snippets by default. Set `extraction_mode: "highlights"` when an agent or RAG prompt needs query-relevant passages. Set `extraction_mode: "full_page"` when you need the whole page, billed at \$1.00 per 1,000 pages fetched live on top of the search call. [Page Content Extraction](/docs/guides/search/retrieve-page-content) covers both modes.

#### Contents API: skip search when you have the URL

Call the Contents API directly when your pipeline already knows the URLs. Adding a Web Search API call first only makes sense when you need URL discovery.

#### Answer API or Research API

The Answer API runs one search pass with no effort tiers, so cost and latency stay flat across queries. Move to the Research API when the question needs multiple searches, domain filters through `source_control`, or structured JSON through `output_schema`. `output_schema` is not available with `lite`, and `frontier` requires `background: true`.

#### Research API or Finance Research API

The Finance Research API returns the same response shape as the Research API. It accepts `deep` or `exhaustive` effort and does not accept `source_control` or `output_schema`. Use it for filings, prices, fundamentals, and financial news.

## REST or MCP

Call the REST APIs when your code owns the HTTP client, retries, and response parsing. Connect the MCP Server when an agent or IDE should decide when to call You.com. Product MCP has no `you-answer` tool, so agents that need a one-pass cited answer call the Answer API over REST. [Build With Agents](/docs/agents) compares the Product MCP server, the Docs MCP Server, and Agent Skills.

## Endpoints and References

Each API has its own endpoint. Every request sends your API key in the `X-API-Key` header.

| API                  | Endpoint                                           | Guide                                     | API reference                                                                     |
| -------------------- | -------------------------------------------------- | ----------------------------------------- | --------------------------------------------------------------------------------- |
| Web Search API       | `POST https://ydc-index.io/v1/search` (also `GET`) | [Overview](/docs/guides/search)           | [/v1/search](/docs/api-reference/search/v1-search)                                |
| Contents API         | `POST https://ydc-index.io/v1/contents`            | [Overview](/docs/guides/contents)         | [/v1/contents](/docs/api-reference/contents)                                      |
| Answer API           | `POST https://api.you.com/v1/answer`               | [Overview](/docs/guides/answer)           | [/v1/answer](/docs/api-reference/answer/v1-answer)                                |
| Research API         | `POST https://api.you.com/v1/research`             | [Overview](/docs/guides/research)         | [/v1/research](/docs/api-reference/research/v1-research)                          |
| Finance Research API | `POST https://api.you.com/v1/finance_research`     | [Overview](/docs/guides/finance-research) | [/v1/finance\_research](/docs/api-reference/finance-research/v1-finance_research) |

The Answer, Research, and Finance Research APIs run only on `api.you.com`. Sending one of those paths to `ydc-index.io` returns `403` with `{"message": "Missing Authentication Token"}`, even when the key is valid.

The MCP Server is a separate endpoint, `https://api.you.com/mcp`, and authenticates with `Authorization: Bearer` or OAuth. [Build With Agents](/docs/agents) covers setup.

The [Quickstart](/docs/quickstart) runs a first request against each REST API.