# Addressing Overview

Context Nest uses the `contextnest://` URI scheme to address documents, sections, tags, and folders within a vault.

## URI format

```
contextnest://[namespace/]path[#anchor][@checkpoint]
```

### Examples

| URI | Resolves to |
|-----|-------------|
| `contextnest://nodes/architecture` | The architecture document |
| `contextnest://nodes/architecture#data-flow` | The "Data Flow" heading |
| `contextnest://nodes/architecture@5` | Architecture at checkpoint 5 |
| `contextnest://engineering/` | All documents in the engineering folder |
| `contextnest://tag/api` | All documents tagged `#api` |
| `contextnest://search/rate+limiting` | Full-text search results |
| `contextnest://platform/infra/networking` | Cross-namespace reference |

## Context links

Use `contextnest://` URIs in your document bodies to create cross-references:

```markdown
For the API design, see [Architecture](contextnest://nodes/architecture-overview).
```

These links are tracked in `context.yaml` as relationship edges and used to compute hub documents.

## Pinned resolution

Append `@N` to pin a URI to a specific checkpoint:

```
contextnest://nodes/architecture@5
```

This resolves to the version of the document that was current at checkpoint 5, not the latest version.