vastlint - IAB XML VAST validator and linter

validate_vast

Validate a VAST XML tag against the IAB VAST 2.0-4.3 specification. Returns all issues found with severity, rule ID, location, and spec reference. A document is valid when errors == 0, regardless of warning or info count. Use wrapper_depth when validating a document inside a wrapper chain.

validate_vast_url

Fetch a VAST tag from a URL and validate it. Handles redirects. Use max_depth to control how deep wrapper chains are followed (default 5, per IAB VAST 4.x recommendation). AI agents typically receive VAST URLs rather than raw XML -- use this tool for that case.

list_rules

List the full catalog of VAST validation rules available in vastlint. Returns rule IDs, default severities, and descriptions. Call this once and cache the result -- the catalog is static. Use rule IDs from this list with explain_rule for full details and fix guidance.

explain_rule

Get full details for a specific VAST validation rule: description, spec reference, severity, what triggers it, and how to fix it. Use rule IDs from list_rules. This is the primary tool for understanding and fixing VAST issues flagged by validate_vast.

fix_vast

Auto-fix a VAST XML tag. Applies all deterministic, safe fixes: HTTP → HTTPS upgrades in all URL-bearing elements, and removal of deprecated attributes. Returns the repaired XML, a list of every fix applied (rule ID + description + path), and any remaining issues that require manual intervention. Always re-validate the returned xml with validate_vast to confirm no errors remain.

get_adcp_capabilities

AdCP protocol discovery. Returns the AdCP version, supported protocols, and governance capabilities of this vastlint agent. Call this first when integrating vastlint into an AdCP creative pipeline — it declares which VAST creative features can be evaluated (spec compliance, HTTPS enforcement, wrapper depth). Part of the Ad Context Protocol (AdCP 3.0) specification.

list_content_standards

AdCP content-standards specialism. Lists content governance standards. When called with an 'account' object, returns buyer-defined standards stored for that brand. Without an account, returns the built-in catalog of VAST-relevant standards. Supports cursor-based pagination via the 'pagination' object. Requires Bearer authentication: Authorization: Bearer <api_key.

create_content_standards

AdCP content-standards specialism. Creates a new set of content quality policies for a brand. Policies include brand safety rules, imagery quality requirements, and compliance constraints. Returns a standards_id that can be used with calibrate_content and validate_content_delivery. Requires Bearer authentication.

get_content_standards

AdCP content-standards specialism. Retrieves the full details of a specific content standard, including all policies and their enforcement levels. Requires Bearer authentication.

update_content_standards

AdCP content-standards specialism. Updates the policies on an existing content standard set. The supplied policies array replaces the existing policy set. Requires Bearer authentication.

calibrate_content

AdCP content-standards specialism. Evaluates a creative artifact against a content standard set before delivery. Returns a per-policy verdict and an overall pass/fail result. Use this as a pre-flight check before launching a campaign. Requires Bearer authentication.

validate_content_delivery

AdCP content-standards specialism. Validates that delivered creatives met the content standards. Accepts delivery records with creative references and returns per-record compliance status plus an overall summary. Requires Bearer authentication.

list_creatives

AdCP creative governance. Lists creatives known to this agent. For a validation-only agent like vastlint, this always returns an empty collection — creatives are validated on demand via validate_vast rather than stored. Requires Bearer authentication.