Rule frontmatter

Every VectorLint rule file begins with a YAML frontmatter block that controls how VectorLint runs the review, handles the result, and reports violations. The Markdown body that follows is the prompt sent to the LLM.

---
id: MyRule
name: My Rule
type: check
severity: error
---

Your rule instructions go here.

Required fields

Field	Type	Description
`id`	string	Unique identifier for the rule. Used in CLI output and in `.vectorlint.ini` overrides. PascalCase recommended (e.g., `GrammarChecker`).
`name`	string	Human-readable display name shown in CLI output.

Optional fields

Field	Default	Description
`specVersion`	(none)	Rule spec version. Set to `1.0.0` for rules using the full judge schema.
`evaluator`	`base`	Evaluator type. Use `base` for standard rules. Use `technical-accuracy` for rules that verify factual claims against live web search (requires a search provider).
`type`	`check`	Review mode. `check` finds specific, countable violations. `judge` scores content against weighted criteria on a 1–4 rubric.
`severity`	`warning`	How a failing result is reported. `error` causes a non-zero exit code; `warning` reports the issue without failing the run.
`evaluateAs`	`chunk`	Whether to evaluate content in sections (`chunk`) or as a single unit (`document`). Chunking is applied automatically to documents over 600 words. Set to `document` to disable chunking for a specific rule.
`strictness`	`standard`	For `check` rules: how strongly error density is penalized when scoring. One of `lenient` (5), `standard` (10, default), `strict` (20), or any positive number. Has no effect on `judge` rules. See Strictness.
`target`	(none)	Regex specification to extract and review a specific portion of the content, such as the H1 headline. See Target fields below.
`criteria`	(none)	Required when `type` is `judge`. Defines the scoring dimensions and their weights. See Criteria fields below.

Target fields

The target field narrows the review to a specific part of the document. It is an object with the following sub-fields:

Field	Type	Required	Description
`regex`	string	Yes	Regular expression pattern to match the target content.
`flags`	string	No	Regex flags (e.g., `"mu"` for multiline and Unicode).
`group`	number	No	Capture group index to extract. If omitted, the full match is used.
`required`	boolean	No	When `true`, a missing match immediately reports an `error` with the `suggestion` text and skips LLM review. When `false` or omitted, a missing match causes VectorLint to review the full document instead.
`suggestion`	string	No	Message shown when `required: true` and the pattern does not match.

Example: targeting only the H1 headline:

target:
  regex: '^#\s+(.+)$'
  flags: "mu"
  group: 1
  required: true
  suggestion: Add an H1 headline for the article.

Criteria fields

The criteria field is an array of criterion objects used with type: judge. Each criterion defines one scoring dimension.

Field	Type	Required	Description
`name`	string	Yes	Human-readable criterion name shown in CLI output.
`id`	string	Yes	Unique identifier for this criterion. PascalCase recommended (e.g., `TechnicalAccuracy`). Referenced in the Markdown body rubric as `# CriterionName <weight=N>`.
`weight`	number	No	Relative importance of this criterion in the weighted average. Higher values increase the criterion’s influence on the final score. Defaults to `1`.
`target`	object	No	Criterion-specific content matching. Uses the same sub-fields as the top-level `target`. Overrides the rule-level target for this criterion only.

Example: judge rule with two weighted criteria:

criteria:
  - name: Technical Accuracy
    id: TechnicalAccuracy
    weight: 40
  - name: Readability
    id: Readability
    weight: 30

Complete example

The following rule uses all commonly-used fields. It targets the H1 headline, judges it against two criteria, and requires the headline to exist before the review runs.

---
specVersion: 1.0.0
evaluator: base
type: judge
id: HeadlineEvaluator
name: Headline Evaluator
severity: error
evaluateAs: document
target:
  regex: '^#\s+(.+)$'
  flags: "mu"
  group: 1
  required: true
  suggestion: Add an H1 headline for the article.
criteria:
  - name: Value Communication
    id: ValueCommunication
    weight: 12
  - name: Curiosity Gap
    id: CuriosityGap
    weight: 2
---

You are a headline evaluator for developer blog posts.

## RUBRIC

# Value Communication <weight=12>

### Excellent <score=4>
Specific, immediately appealing benefit clearly stated.

### Good <score=3>
Clear benefit but less specific impact.

### Fair <score=2>
Vague benefit implied but not stated.

### Poor <score=1>
No apparent benefit to the reader.

# Curiosity Gap <weight=2>

### Excellent <score=4>
Creates genuine intrigue without being misleading.

### Good <score=3>
Mildly interesting, reader may continue.

### Fair <score=2>
Neutral, no curiosity created.

### Poor <score=1>
Actively off-putting or confusing.

Overview

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Required fields

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Complete example

​Required fields

​Optional fields

​Target fields

​Criteria fields

​Complete example

Required fields

Optional fields

Target fields

Criteria fields

Complete example