API Payload Builder
Payload Configuration
JSON Payload
Construct Complex API Payloads
The API Payload Builder is a developer utility designed to visually generate properly structured JSON payloads for AI model endpoints like the Gemini API.
Why use a payload builder?
- Prevent 400 Bad Request Errors: LLM APIs require strict JSON structures for their contents array and generation config objects. This tool ensures your payload is always valid.
- Fast Prototyping: Quickly test different temperature and token limits without manually editing JSON strings in your code.
For a complete walkthrough on how to use this payload, read our Gemini API Developer Guide.
Frequently Asked Questions
Common questions about this tool.
Does this tool send my data to external servers? ▼
No. The API Payload Builder runs 100% client-side. Your prompts, system instructions, and data are processed locally in your browser.
Can I use this for the OpenAI or Anthropic API? ▼
Yes! While optimized for Gemini API structures, the tool allows you to build generic JSON payloads that can be adapted for any REST API.
How do I use the generated JSON? ▼
Simply copy the generated JSON from the output panel and paste it directly into your fetch requests, Postman, or cURL commands.
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