VASTlint MCP Server

by aleksuix Your server? Claim it

answering

VASTlint is answering right now. Last checked 3 min ago. It exposes 15 tools. Last commit 1 Nov 2026.

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

Uptime history 91 days of history · worst day 90%

91 days agonow

100.0%

Uptime 24h

91 of 91 checks

Tools

read from the server

202 ms

Response time

average over 24h

Stars

last commit 1 Nov 2026

What changed 1

Every tool that appeared, vanished or quietly changed what it asks for. Recorded since 27 August 2026. No other catalogue keeps this.

27 Aug a tool appeared inspect_vast

Nothing serious here today

Today is the operative word: we check VASTlint every 15 minutes and re-read its code on every release. Watch it and you find out the day that stops being true.

Connect this server

Endpoint below is the one we actually reach during checks — not the one copied from a README. Last verified 3 min ago.

Claude Code Claude Desktop Codex Cursor VS Code

run in your terminal

claude mcp add vastlint --transport sse https://vastlint.org/mcp

Settings → Connectors → Add custom connector, then paste this address

https://vastlint.org/mcp

~/.codex/config.toml

[mcp_servers.vastlint]
url = "https://vastlint.org/mcp"

.cursor/mcp.json

{
  "mcpServers": {
    "vastlint": {
      "url": "https://vastlint.org/mcp"
    }
  }
}

.vscode/mcp.json

{
  "servers": {
    "vastlint": {
      "type": "sse",
      "url": "https://vastlint.org/mcp"
    }
  }
}

Available tools 15

Read directly from the server with tools/list, grouped by what they act on. If a tool disappears, we record the date.

content

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.

delete_content_standards

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.

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.

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>.

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.

validate

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.

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.

adcp

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.

calibrate

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.

creatives

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.

explain

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

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.

inspect

inspect_vast

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.

rules

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.

Endpoints

URL	Transport	State	Latency	Checked
https://vastlint.org/mcp	sse	answering	122 ms	3 min ago

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VASTlint — questions

Answers built from our own checks of this server.

What can VASTlint do?

It exposes 15 tools, read directly from the server on our last check. Among them: calibrate_content, create_content_standards, delete_content_standards, explain_rule, fix_vast, get_adcp_capabilities and 9 more. The full list with descriptions is on this page — we take it from the server itself via tools/list, not from a README. How MCP servers expose tools in the first place →

What is VASTlint mostly used for?

Its tools cluster around content and validate. That is what this server is built to work with — the grouping comes from the actual tool names, not from a category we assigned.

Is VASTlint working right now?

We send a real MCP handshake every 15 minutes. Over the last 24 hours 91 of 91 checks got a reply (100.0%), average response time 202 ms. The bar chart above shows every period we have measured.

How do I connect VASTlint?

Copy the ready config from this page. We generate it for Claude Code, Claude Desktop, Codex, Cursor and VS Code, each in the form that client actually reads. It is a remote server, so there is nothing to install — the client connects to the address.

Does VASTlint need an API key?

No. VASTlint completed a full MCP handshake with us as an anonymous client and listed its tools without asking for anything. All 15 of them are readable on this page. This is what we observed, not what the docs claim.

How fast is VASTlint?

It answers our handshake in 202 ms on average, which is faster than 70% of all working MCP servers we measure. The comparison comes from our own checks across the whole registry, every 15 minutes.

Is VASTlint open source?

The code is open source: it is published under the Apache-2.0 licence, written in Rust, 19 stars on GitHub and 1 open issue. The licence covers the code in the repository, not the hosted service at vastlint.org, which runs on its operator's own terms.