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

# Introduction

> Overview of the Factagora API

## Overview

The Factagora API gives you programmatic access to the Factagora knowledge graph, a continuously updated database of fact-checked claims, predictions, evidence, and causal relationships extracted from global news and research sources. It's designed as a drop-in layer: call it from any language or framework, on top of the LLM and retrieval stack you already run.

## Built on a Temporal Knowledge Graph

Behind the API is a **Temporal Knowledge Graph (TKG)**. Instead of storing loose document chunks, Factagora stores each fact as a **FactBlock**, a time-stamped, causally linked proposition. This design makes the knowledge graph especially precise about two questions most sources get wrong: **when** something was true, and **why** it happened.

<CardGroup cols={2}>
  <Card title="Accurate about *when*" icon="clock">
    Facts are bi-temporal: each one records when an event occurred and the window during which it stays valid. Queries are point-in-time, so the API returns only the facts that were valid at the moment you ask about. Later information never leaks backward into an earlier answer, which keeps time-sensitive reasoning free of hindsight bias.
  </Card>

  <Card title="Accurate about *why*" icon="diagram-project">
    Causal relationships are first-class. Facts are connected by typed links, such as *causes*, *triggers*, *contributes to*, and *prevents*, that capture the mechanism, the time lag, and a confidence level, and that are promoted from hypothesis to verified as evidence accumulates. Correlation is kept distinct from causation, so the API can explain *why* facts connect, not just that they co-occur.
  </Card>
</CardGroup>

The result: answers that are grounded not only in *what* is true, but in *when* it was true and *what caused it*, so AI agents can reason about timelines and cause-and-effect with verifiable support.

## Base URL

```
https://api.factagora.com
```

## Authentication

All Factagora endpoints are authenticated using API keys. [Get your free API key.](https://factagora.com/en/playground/tokens)

<Info>
  **You don't need to create one to get started.** A default API key is issued automatically the first time you sign in to Factagora. Visit [Settings → API Keys](https://factagora.com/en/playground/tokens) to copy it or create additional keys.
</Info>

```bash theme={null}
curl -X GET "https://api.factagora.com/api/v1/fact-search?q=bitcoin" \
  -H "Authorization: Bearer fag_YOUR_API_KEY"
```

API keys follow the format `fag_...`. See [Authentication](/api-reference/authentication) for details.

## Endpoints

<CardGroup cols={2}>
  <Card title="/fact-search" icon="newspaper" href="/api-reference/fact-search">
    Search recent news articles from global sources.
  </Card>

  <Card title="/fact-check" icon="circle-check" href="/api-reference/fact-checker">
    Verify the truthfulness of a claim with AI verdicts and supporting evidence.
  </Card>

  <Card title="/evidence" icon="magnifying-glass" href="/api-reference/evidence-finder">
    Find credibility-scored evidence supporting or contradicting any topic.
  </Card>

  <Card title="/deep-research" icon="book-open" href="/api-reference/deep-research">
    Run comprehensive multi-source research on a topic.
  </Card>

  <Card title="/timeseries" icon="chart-line" href="/api-reference/timeseries">
    Extract timeseries data from a URL or text.
  </Card>

  <Card title="/causality-graph" icon="diagram-project" href="/api-reference/causality-graph">
    Extract a causal relationship graph from a URL or text.
  </Card>

  <Card title="/fingerprint/embed" icon="fingerprint" href="/api-reference/fingerprint/fingerprint-embed">
    Embed a TKG-based watermark into content for provenance tracking.
  </Card>

  <Card title="/fingerprint/detect" icon="shield-check" href="/api-reference/fingerprint/fingerprint-detect">
    Detect whether content matches a previously fingerprinted source.
  </Card>
</CardGroup>

## Response Format

All responses are JSON. Successful responses return `200`. Errors return `400` (validation) or `401` (authentication).

```json theme={null}
{
  "error": "Unauthorized",
  "message": "Missing Bearer token",
  "statusCode": 401
}
```