VASTlint

Measured conclusion: Deep-tested. L2 outcome: tools_ok.

Validate VAST, VMAP, and DAAST ad tags against IAB specs. 246 rules, pure Rust core.

Add to your agent

Copy this into your MCP client config:

{
  "mcpServers": {
    "VASTlint": {
      "url": "https://vastlint.org/mcp",
      "transport": "streamable-http"
    }
  }
}

Measured tools (15)

• validate_vast read-only

  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.

  Parameters:

  • xml (required) — string — Raw VAST XML string to validate.
  • wrapper_depth — integer — Current wrapper chain depth (0 = root document). Default: 0.

  Hints: read-only yes · destructive no · idempotent yes · open-world no

• validate_vast_url read-only

  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.

  Parameters:

  • url (required) — string — URL of a VAST tag to fetch and validate.
  • max_depth — integer — Maximum wrapper chain depth to follow. Default: 5 (IAB VAST 4.x recommendation).

  Hints: read-only yes · destructive no · idempotent no · open-world yes

• inspect_vast read-only

  Follow a VAST wrapper chain from a URL, fetching and validating every hop. Returns each hop as a structured object: AdSystem, AdTitle, Duration, impression count, tracking event count, media files (with MIME type, dimensions, bitrate, URL), companion count, and per-hop validation issues. The final InLine hop contains the actual creative. Use this to debug wrapper chains, verify creative assets, or analyse a full ad delivery path. max_depth defaults to 5 per IAB recommendation.

  Parameters:

  • url (required) — string — URL of the first VAST tag in the chain to inspect.
  • max_depth — integer — Maximum wrapper hops to follow before stopping. Default: 5 (IAB VAST 4.x recommendation).

  Hints: read-only yes · destructive no · idempotent no · open-world yes

• list_rules read-only

  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.

  Hints: read-only yes · destructive no · idempotent yes · open-world no

• explain_rule read-only

  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.

  Parameters:

  • rule_id (required) — string — Rule ID to explain, e.g. "VAST-4.1-adservingid-missing". Use list_rules to get valid IDs.

  Hints: read-only yes · destructive no · idempotent yes · open-world no

• 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.

  Parameters:

  • xml (required) — string — Raw VAST XML string to auto-fix.
  • wrapper_depth — integer — Current wrapper chain depth (0 = root document). Default: 0.

  Hints: read-only no · destructive no · idempotent yes · open-world no

• get_adcp_capabilities read-only

  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.

  Parameters:

  • context — object — Caller-supplied context object. Echoed back unchanged in the response.
  • protocols — array — Filter to specific protocol names. When omitted, returns all supported protocols.
  • adcp_major_version — integer — AdCP major version the caller's payloads conform to. When omitted, assumes highest supported version (3).

  Hints: read-only yes · destructive no · idempotent yes · open-world no

• list_content_standards read-only

  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>.

  Parameters:

  • account — object — Buyer account context (brand domain + operator).
  • context — object — Caller-supplied context object. Echoed back unchanged in the response.
  • page_token — string — Legacy top-level alias.
  • pagination — object — Cursor-based pagination controls. Preferred over top-level max_results/page_token.
  • max_results — integer — Legacy top-level alias.

  Hints: read-only yes · destructive no · idempotent yes · open-world no

• 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.

  Parameters:

  • account (required) — object — Buyer account that owns this content standard (brand domain required).
  • policies (required) — array — Array of content quality policies. Each policy has an ID, enforcement level (must/should/may), and natural-language rule text.
  • scope — object — Optional scope constraints: restrict policies to specific languages or channels.
  • context — object — Caller-supplied context object. Echoed back unchanged in the response.
  • idempotency_key — string — Optional unique key to make this request idempotent. Re-submitting the same key returns the original result without creating a duplicate.

  Hints: read-only no · destructive no · idempotent no · open-world no

• get_content_standards read-only

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

  Parameters:

  • standards_id (required) — string — ID of the content standard set to retrieve. Returned by create_content_standards.
  • account — object — Buyer account context. Scopes the lookup to a specific brand.
  • context — object — Caller-supplied context object. Echoed back unchanged in the response.

  Hints: read-only yes · destructive no · idempotent yes · open-world no

• 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.

  Parameters:

  • standards_id (required) — string — ID of the content standard set to update. Returned by create_content_standards.
  • policies (required) — array — Replacement policy array. Fully replaces the existing policies on the standard set.
  • account — object — Buyer account context. Scopes the update to a specific brand.
  • context — object — Caller-supplied context object. Echoed back unchanged in the response.
  • idempotency_key — string — Optional unique key to make this request idempotent. Re-submitting the same key returns the original result without creating a duplicate.

  Hints: read-only no · destructive no · idempotent no · open-world no

• delete_content_standards destructive

  AdCP content-standards specialism. Permanently removes a content standard set. Callers relying on the standards_id for calibrate_content or validate_content_delivery should retire those integrations first. Requires Bearer authentication.

  Parameters:

  • standards_id (required) — string — ID of the content standard set to delete. Returned by create_content_standards.
  • account — object — Buyer account context. Scopes the deletion to a specific brand.
  • context — object — Caller-supplied context object. Echoed back unchanged in the response.
  • idempotency_key — string — Optional unique key to make this request idempotent. Re-submitting the same key returns the original result instead of re-evaluating a since-changed state.

  Hints: read-only no · destructive yes · idempotent yes · open-world no

• calibrate_content read-only

  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.

  Parameters:

  • standards_id (required) — string — ID of the content standard set to evaluate against. Returned by create_content_standards.
  • artifact (required) — object — Creative artifact to evaluate: metadata and asset URLs (image, video) to check against each policy.
  • account — object — Buyer account context. Scopes the evaluation to a specific brand.
  • context — object — Caller-supplied context object. Echoed back unchanged in the response.
  • idempotency_key — string — Optional unique key to make this request idempotent. Re-submitting the same key returns the original result without re-evaluating.

  Hints: read-only yes · destructive no · idempotent no · open-world no

• validate_content_delivery read-only

  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.

  Parameters:

  • standards_id (required) — string — ID of the content standard set to validate delivery against. Returned by create_content_standards.
  • records (required) — array — Delivery records to validate. Each record references a creative artifact that was delivered.
  • account — object — Buyer account context. Scopes the validation to a specific brand.
  • context — object — Caller-supplied context object. Echoed back unchanged in the response.

  Hints: read-only yes · destructive no · idempotent no · open-world no

• list_creatives read-only

  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.

  Parameters:

  • context — object — Caller-supplied context object. Echoed back unchanged in the response.
  • page_token — string — Opaque pagination cursor.
  • max_results — integer — Maximum number of creatives to return per page.

  Hints: read-only yes · destructive no · idempotent yes · open-world no

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