Use BestMCPServers Tool API with ChatGPT Actions

What ChatGPT Actions need from this API

ChatGPT Actions work best when the OpenAPI document is small, explicit, and uses stable operation IDs. BestMCPServers exposes a focused OpenAPI 3.1 document with five operations: formatJson, validateJson, encodeBase64, decodeBase64, and decodeJwt. Each endpoint accepts one content field and returns a consistent success or error envelope, so an assistant can safely call tools without understanding page UI state.

For the current MVP there is no login, database, payment, or API key. That keeps the action setup simple: import the schema, select the operations, and test calls against production endpoints. Rate limiting can be added later at the Cloudflare layer without changing the OpenAPI contract.

https://bestmcpservers.com/openapi.json

Step-by-step setup

Create or edit a Custom GPT, open the Actions section, and import the OpenAPI schema URL. After import, verify that the operation names are visible and that the server URL is https://bestmcpservers.com. Use the test panel to send a small JSON formatting request before adding the action to a real workflow.

A good first test is to ask ChatGPT to format a compact JSON object, validate an intentionally broken JSON string, encode a short text value, decode a Base64 string, and inspect a sample JWT payload. These calls cover every endpoint and confirm that both success and error responses are usable.

POST /api/json/format
{
  "content": "{\"name\":\"BestMCPServers\"}"
}

Recommended Action descriptions

Use clear descriptions that tell ChatGPT when to call each operation. For example, formatJson should be used when the user wants readable JSON; validateJson should be used when the user asks whether JSON is syntactically valid; decodeJwt should be used only to inspect header and payload, not to verify security.

The JWT endpoint intentionally returns verified: false. This is important because JWT decoding is not signature verification. The assistant should state that decoded claims are informational unless the token signature is verified by the application that issued it.

Production notes

The API is intentionally narrow. It does not store user input, does not create accounts, and does not require API keys. For sensitive production tokens or secrets, users should avoid pasting confidential data into any hosted tool unless they understand their own security policy.

If traffic grows, the next production step is Cloudflare rate limiting for /api/* by IP. API keys, quotas, and analytics should come only after the SEO and API-call demand is validated.

FAQ