# Validation Rules

Context Nest defines validation rules for documents, source nodes, and cross-references. Run validation with:

```bash
ctx validate              # Validate all documents
ctx validate nodes/api    # Validate a specific document
ctx validate --json       # JSON output for CI
```

## Document rules

| Rule | Check |
|------|-------|
| 1 | `title` is present and 1–200 characters |
| 2 | `type` is a recognized node type |
| 3 | `tags` are an array of strings starting with `#` |
| 4 | `status` is `draft` or `published` |
| 5 | `version` is a positive integer |
| 6 | `created_at` / `updated_at` are valid ISO 8601 timestamps |
| 7 | `derived_from` is a valid `contextnest://` URI |
| 8 | Body contains valid GFM markdown |

## Source node rules

| Rule | Check |
|------|-------|
| 9 | `source.transport` is `mcp`, `rest`, `cli`, or `file` |
| 10 | `source.server` references a server in `config.yaml` |
| 11 | `source.tools` is an array of strings |
| 12 | `source.depends_on` URIs are valid `contextnest://` URIs |
| 13 | `source.cache_ttl` is a non-negative integer |
| 14 | Each `depends_on` URI resolves to a `type: source` node |
| 15 | No circular dependencies in the source graph |

## Cross-reference rules

| Rule | Check |
|------|-------|
| 16 | All `contextnest://` URIs in document bodies resolve to existing documents |
| 17 | Frontmatter `depends_on` and body-level references are consistent |

## CI integration

```yaml
# GitHub Actions
- name: Validate vault
  run: ctx validate --json
```

Exit code is non-zero if any validation fails.