> ## Documentation Index
> Fetch the complete documentation index at: https://docs.extruct.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Introduction

> Choose the right Extruct API workflow for your goal.

## Start with your goal

Extruct API gives you three ways to discover companies, Deep Research for cited reports on companies and people, and AI Tables for enrichment and scoring on either Extruct results or your own company list.

Use:

* Semantic Search for fast, recall-first search over the Extruct index.
* Lookalike Search when you already have a representative company domain or UUID.
* Deep Search when you need a more deliberate shortlist scored against custom criteria.
* Deep Research when you need a deep, cited report on one research target — a company, a person, or a team: account plans, lead and buyer research, diligence.
* AI Tables when you want to enrich, score, and review a company list in a reusable workflow.

<Columns cols={2}>
  <Card title="Lookalike Search" icon="users" href="/api-guides/search/lookalike-search" cta="Open guide">
    Start from a company domain or UUID and find similar companies ranked from the Extruct index.
  </Card>

  <Card title="Semantic Search" icon="search" href="/api-guides/search/semantic-search" cta="Open guide">
    Start from a natural-language query and retrieve matching companies instantly from the Extruct index.
  </Card>

  <Card title="Deep Search" icon="radar" href="/api-guides/search/deep-search" cta="Open guide">
    Run asynchronous, agent-based discovery that ranks companies against natural-language criteria using web, Extruct DB, Maps, and LinkedIn.
  </Card>

  <Card title="Deep Research" icon="file-magnifying-glass" href="/api-guides/research/deep-research" cta="Open guide">
    Submit a detailed research brief about a company, a person, or a team and get back a cited report — markdown or structured to your own schema.
  </Card>

  <Card title="AI Tables" icon="table" href="/api-guides/ai-tables/ai-table-basics" cta="Open guide">
    Start with companies from Extruct or from your own company list, then run repeatable enrichment and scoring workflows.
  </Card>
</Columns>

## Authentication

```bash theme={null}
export EXTRUCT_API_TOKEN="YOUR_API_TOKEN"

curl --get "https://api.extruct.ai/v1/user" \
  -H "Authorization: Bearer ${EXTRUCT_API_TOKEN}"
```

Generate tokens in the [Dashboard API Tokens page](https://app.extruct.ai/api-tokens). For full setup, see [Authentication](/api-reference/authentication).

## Next step

* Start with [Semantic Search Guide](/api-guides/search/semantic-search) if you need to discover companies
* Or start with [Deep Research](/api-guides/research/deep-research) if you need a cited report on a company or a person
* Or start with [AI Tables Basics](/api-guides/ai-tables/ai-table-basics) if you already have a company list
* Or connect [Extruct MCP](/build-with-ai-agents/extruct-mcp) in your editor or agent (Cursor, VS Code, Claude, Codex, and others)
* Or use the [Extruct API Skill](/build-with-ai-agents/extruct-api-skill) if you want the skill’s embedded API workflows and `EXTRUCT_API_TOKEN` from your coding agent
* Or browse the [API Reference](/api-reference/introduction)