Captcha Generator Skill

Overview

Sending a request creates a fresh captcha challenge without requiring query parameters. The response provides a signed download URL to serve the challenge graphic to users, the correct solution string to verify their submission on your server, a unique challenge ID, and a millisecond expiration timestamp.

Live Test Captcha Generator Skill Skill →

The tool

Once your client is connected to the VerveKit server, this appears in its tool list as CaptchaGeneratorSkill. It is read-only and open-world — it fetches and never mutates anything on your side — so most clients call it without asking you to confirm.

Tool call

{
  "name": "CaptchaGeneratorSkill",
  "arguments": {}
}

Connecting

One server URL covers every skill in the catalog, including this one. Authorization is OAuth: the client opens a browser once, and there is no key to paste into a config file.

{
  "mcpServers": {
    "vervekit": {
      "url": "https://api.vervekit.com/v1/mcp"
    }
  }
}

Per-client setup — Claude, Cursor, VS Code, ChatGPT — is on the MCP setup page.

What the model gets back

The result carries a structuredContent object matching the tool's declared outputSchema, so a client reads fields without parsing prose. status is "ok" and error is null on success; a null field means the value was not available for that input, not that the call failed.

Result

{
  "status": "ok",
  "error": null,
  "data": {
    "id": "e183c54c-5bf6-455e-bc96-195685cee71c",
    "expires": 1766010041360,
    "solution": "fwvct",
    "downloadURL": "https://storage.googleapis.com/apiverve/APIData/captchagenerator/e183c54c-5bf6-455e-bc96-195685cee71c.png?GoogleAccessId=635500398038-compute%40developer.gserviceaccount.com&Expires=1766010041&Signature=LLBhTrpVAk%2Bzx%2B2U7sdbIfjUOm%2FEe4hP7ebqGfphThctFRbHs9oyHPJ3J7BCAu71WswQr1qOKh%2BQddOPTGFCVUVL%2BlN1Qxt%2BlIBXYVM7%2FzW3YlfbHmFbXaesr%2BC7pFW6ekZ88fobbOP%2FcGbKdtVL1Vz9ceomtqUw%2Bl9Mwy3FCkpmwPHzGxW56%2BAHB%2B5TQgH2S%2FcmkJkPUxMSGnztQerMNB7V2JrhpuBLZl7N%2FPRucwJswVX6LYYOfNlvrFuxwJwS%2BBot9TesdYlPPDZgOfBo0%2FGgGMzIc753aPUIzkJoeMyPZgJGRilPQNrWJgp%2F7mmx4WNq6QgdIZPlQ36FlDHMsg%3D%3D"
  }
}

Response fields

Paths are relative to data. Premium fields are absent rather than zeroed on plans that do not include them, so check for presence instead of comparing to 0.

Field	Type	Example	Description
`id`	string	`e183c54c-5bf6-455e-bc96-195685cee71c`	Unique identifier for the generated captcha
`expires`	number	`1766010041360`	Unix timestamp when captcha expires in milliseconds
`solution`	string	`fwvct`	The correct answer string for the captcha
`downloadURL`	string	https://storage.googleapis.com/apiverve/APIData/captchagenerator/e183c54c-5bf6-455e-bc96-195685cee71c.png?GoogleAccessId=635500398038-compute%40developer.gserviceaccount.com&Expires=1766010041&Signature=LLBhTrpVAk%2Bzx%2B2U7sdbIfjUOm%2FEe4hP7ebqGfphThctFRbHs9oyHPJ3J7BCAu71WswQr1qOKh%2BQddOPTGFCVUVL%2BlN1Qxt%2BlIBXYVM7%2FzW3YlfbHmFbXaesr%2BC7pFW6ekZ88fobbOP%2FcGbKdtVL1Vz9ceomtqUw%2Bl9Mwy3FCkpmwPHzGxW56%2BAHB%2B5TQgH2S%2FcmkJkPUxMSGnztQerMNB7V2JrhpuBLZl7N%2FPRucwJswVX6LYYOfNlvrFuxwJwS%2BBot9TesdYlPPDZgOfBo0%2FGgGMzIc753aPUIzkJoeMyPZgJGRilPQNrWJgp%2F7mmx4WNq6QgdIZPlQ36FlDHMsg%3D%3D	Download URL for the captcha image with signature

Failure modes

Errors come back as tool errors carrying a sentence the model can act on, not a bare status code. Error handling covers the full list.

Status	What it means
`400` / `422`	The arguments did not validate. The message names the offending one.
`401`	The OAuth session is invalid or expired — reconnect the server.
`403`	Blocked by a key restriction or an IP allow-list. Never a bad identity.
`404`	This skill is not part of VerveKit. Check the catalog.
`429`	Out of credits, or a brief rate limit. The message tells them apart.

A call costs 10 credits each time the tool actually runs; a model that reasons about the tool without calling it costs nothing.

Use cases

Registration Form Protection: To block automated spam registrations, web apps fetch a challenge image for the signup form and check submitted text against the returned solution.
Failed Login Throttling: When visitors trigger multiple failed login attempts, authentication services display a captcha image to verify that a person is behind the keyboard.
Contact Form Verification: Community forums attach challenge images to public inquiry forms, using the millisecond expiration timestamp to invalidate stale submissions.
Password Reset Defense: Require visitors to solve a visual challenge before sending password reset links to prevent bad actors from triggering bulk recovery emails.

Other ways to use Captcha Generator Skill

Set up Captcha Generator Skill on VerveKit, or reach the same source a different way. Your VerveKit account and credits work on all of them — one key, one balance.

Call it as a REST APIOne HTTPS endpoint and an x-api-key header, with SDKs for Node, Python and .NET.APIVerve →Reference →