MCP setup

Let AI agents validate and fix HTML5 ad creatives without leaving the editor. ad-preflight runs as an MCP server in Cursor (or any MCP-compatible client), validating against IAB standards and platform requirements for Google Ads, DV360, Sizmek, Adform, and more.

See also: CLI guide for full command reference · CI/CD guide for pipelines · Deep Audit (Pro) for runtime checks

How it works

Exposes one tool: validate_ad_creative - validates and optionally auto-fixes an HTML5 ad creative
Also registers two prompts (analyze_ad, fix_ad) and three reference resources (platform specifications, file size limits, allowed file types) - your MCP client lists them alongside the tool
Runs over stdio - Cursor starts it on demand, no separate server process
Same validation rules as the CLI: click handlers (clickTag, Enabler API, Exit API), ad.size meta, HTTPS, file types, size limits, IAB dimensions

Configuration

Add ad-preflight to your MCP config: .cursor/mcp.json (project-level) or ~/.cursor/mcp.json (global).

Recommended (npx)

Works whether the package is installed locally or not:

{
  "mcpServers": {
    "ad-preflight": {
      "command": "npx",
      "args": ["-y", "@ad-preflight/cli", "mcp"]
    }
  }
}

Alternative (explicit path)

Use when you prefer a fixed install path or want to avoid npx:

{
  "mcpServers": {
    "ad-preflight": {
      "command": "node",
      "args": ["node_modules/@ad-preflight/cli/dist/mcp-server.js"]
    }
  }
}

Restart Cursor after changing the config.

Tool: `validate_ad_creative`

Validates and packages an HTML5 ad creative according to platform specs.

Parameter	Type	Required	Default	Description
`folderPath`	string	yes	-	Absolute path to the creative folder - a single creative, or a campaign folder with one subfolder per size
`type`	string	no	`"standard"`	Ad type: `standard`, `amp`, or `app`
`fix`	boolean	no	`false`	Auto-fix issues (inject ClickTag, HTTPS, ad.size). Rewrites the creative in place and backs the original up to `<folder>_original.zip`
`strictDimensions`	boolean	no	`false`	Fail when the ad size is not an IAB standard dimension (default: warn only)

What the agent sees

The tool returns a structured result the agent can act on:

Field	Meaning
`success`	`false` means the creative must not be uploaded
`issues`	Blocking problems that made validation fail
`warnings`	Non-blocking problems worth reviewing
`fixLogs`	What was changed when `fix` was `true`
`packages`	Every ZIP produced - one entry per size for a multi-size campaign
`packagesSkipped`	Sizes that failed validation and produced no ZIP
`originalZipPath`	Backup of the pre-fix creative (only when `fix` was `true`)
`logs`	Progress messages from the run

A creative that fails validation is a normal answer, not a tool error: the agent gets success: false plus the findings. Tool errors are reserved for runs that can't produce a verdict at all (for example, the folder doesn't exist).

Example prompts

Once MCP is configured, ask the agent naturally:

Prompt	What happens
"Validate this ad creative"	Runs validation only (`fix: false`)
"Check and fix issues in this ad"	Validates and auto-fixes (`fix: true`)
"Validate this AMP ad"	Validates with `type: "amp"`
"Validate every size in this campaign"	Validates each size subfolder and reports which ones passed
"Is this ad ready for Google Ads?"	Validates against platform requirements

The agent calls validate_ad_creative with the appropriate parameters based on your prompt.

Agent suggestions (optional)

Write agent instructions into your project so agents recognise HTML5 ad creatives and know to validate them:

npx @ad-preflight/cli init-rules

It writes three files, because no single format is read everywhere:

File	Read by
`AGENTS.md`	the cross-tool convention most agent CLIs and IDEs look for
`.cursor/rules/ad-preflight.mdc`	current Cursor
`.cursorrules`	older Cursor versions (legacy)

Existing files are left alone; pass --force to overwrite. This adds project-level instructions only - you still need the MCP config above for the tool itself to work.

Troubleshooting

Problem	Solution
Tool not appearing in Cursor	Restart Cursor after editing `.cursor/mcp.json`
Wrong path error (node variant)	Verify the path to `mcp-server.js` is correct from your project root. Use the npx config to avoid path issues
Want CLI fallback instead	Run `npx @ad-preflight/cli package ./ad --json` and parse the output. See CI/CD guide