> For the complete documentation index, see [llms.txt](https://docs.graphlit.dev/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.graphlit.dev/api-guides/use-cases/knowledge-graph.md).

# Knowledge Graph

Extract entities, build knowledge graphs, and query relationships from your content.

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## Core Concepts

* [Observable/Observation Model](/api-guides/use-cases/knowledge-graph/observable-observation-model-explained.md) - **Start here** - Entity architecture
* [Entity Types Comprehensive](/api-guides/use-cases/knowledge-graph/observable-entity-types-comprehensive.md) - All 20+ types (12 medical included)
* [Confidence and Occurrences](/api-guides/use-cases/knowledge-graph/observable-confidence-and-occurrences.md) - Timestamps, pages, bounding boxes
* [Workflow Extraction Explained](/api-guides/use-cases/knowledge-graph/workflow-extraction-how-it-works.md) - How LLMs extract entities
* [Configure Entity Extraction](/api-guides/use-cases/knowledge-graph/workflow-configure-entity-extraction.md) - Workflow setup

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## End-to-End Examples

Build complete knowledge graphs from various sources:

* [From PDF Documents](/api-guides/use-cases/knowledge-graph/knowledge-graph-from-pdf-documents.md) - Most popular - Complete pipeline
* [From Emails](/api-guides/use-cases/knowledge-graph/knowledge-graph-from-emails.md) - Gmail/Outlook → contact networks
* [From Slack Messages](/api-guides/use-cases/knowledge-graph/knowledge-graph-from-slack-messages.md) - Team collaboration graphs
* [From GitHub Repositories](/api-guides/use-cases/knowledge-graph/knowledge-graph-from-github.md) - Contributors, repos, dependencies
* [From Meeting Recordings](/api-guides/use-cases/knowledge-graph/knowledge-graph-from-meetings.md) - Audio → transcript → entities
* [From Medical Content](/api-guides/use-cases/knowledge-graph/knowledge-graph-medical-content.md) - Clinical entity extraction (12 types)

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## Graph Queries

* [Relationship Queries](/api-guides/use-cases/knowledge-graph/observable-relationship-queries.md) - Person → Organization patterns
* [Advanced Graph Patterns](/api-guides/use-cases/knowledge-graph/observable-query-graph-patterns.md) - Subgraphs, centrality, paths
* [Entity Deduplication](/api-guides/use-cases/knowledge-graph/observable-entity-deduplication.md) - How Graphlit handles duplicates
* [Knowledge Graph Enrichment](/api-guides/use-cases/knowledge-graph/knowledge-graph-enrichment.md) - External data augmentation

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## Content + KG Integration

* [Filter Content by Entities](/api-guides/use-cases/knowledge-graph/content-filter-by-entities.md) - Find all content mentioning entity
* [Entity Co-Occurrence](/api-guides/use-cases/knowledge-graph/content-entity-co-occurrence.md) - Network analysis
* [KG-Guided Search](/api-guides/use-cases/knowledge-graph/knowledge-graph-guided-search.md) - Entity expansion
* [Entity Timeline](/api-guides/use-cases/knowledge-graph/observable-content-timeline.md) - First/last mentions
* [Export with Entities](/api-guides/use-cases/knowledge-graph/content-export-with-entities.md) - JSON/CSV export

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## Related Tutorials

* [Knowledge Graph Quickstart](/tutorials/knowledge-graph.md) - 20-minute complete tutorial

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