#284 · Developer Tool

OpenAPI Request Body Generator

Generate request-body fixtures for operations that declare an OpenAPI 3 requestBody. The page selects JSON media types first, falls back to the first declared media type, and respects media-level examples before deriving a value from the schema. Output is grouped by method and path with the chosen content type and required flag. That makes it practical for assembling test cases without losing the operation context that a bare JSON example would omit.

Developer Input

OpenAPI JSON
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How to use this developer tool

  1. Paste a JSON-formatted API document or load the included sample.
  2. Check that the document shape matches the label above the editor.
  3. Select “Generate Request Bodies” or press Ctrl/Cmd + Enter.
  4. Review the summary and download the copy-ready result.

What this developer tool does

The generator scans operations with requestBody content and creates a structured fixture record for each one.

Named media examples are preferred, followed by a direct media example and a schema-derived value. Local requestBody references are resolved.

Authentication headers, query parameters, and server URLs are intentionally not fabricated.

Example

The Sample button loads a small specification chosen for this operation. Running it produces the same structured fields shown in the output panel.

{
  "openapi": "3.0.3",
  "info": {
    "title": "Users",
    "version": "1"
  },
  "paths": {
    "/users": {
      "post": {
        "operationId": "createUser",
        "requestBody": {
          "required": true,
          "content": {
            "application/json": {
              "schema": {
                "type": "object",
                "properties": {
                  "email": {
                    "type": "string",
                    "example": "dev@example.com"
                  },
                  "role": {
                    "type": "string",
                    "enum": [
                      "admin",
                      "member"
                    ]
                 
…

Use cases

  • Review an API contract during a pull request.
  • Prepare documentation or deterministic test fixtures.
  • Find migration work before changing generators or clients.
  • Export a focused report without sharing the source document.

Tips for reliable output

  • Bundle remote references before running the page.
  • Keep operation IDs stable across published versions.
  • Prefer explicit examples for domain-specific values.
  • Validate the complete document after applying generated output.
  • Commit the original specification before a conversion.

Processing details

Operations without requestBody are skipped. The selected media type and required status are retained beside each generated body.

Multipart encoding details, external references, and application-specific validation rules are not executed. Input must be OpenAPI 3 JSON.

Frequently asked questions

Does this page accept YAML OpenAPI files?

No. This browser-only implementation accepts JSON so parsing behavior stays predictable without loading an external YAML library. Convert YAML to JSON first.

Are external $ref URLs resolved?

No. Local JSON Pointer references are handled where the operation needs them, but remote references are not fetched.

Does the result replace a full OpenAPI validator?

No. OpenAPI Request Body Generator performs its documented transformation or audit. Use a standards-aware validator before publishing a specification.

Is the specification uploaded to a server?

No. Processing runs in the current browser tab. The page does not send the pasted document to an API.

Can I download the result?

Yes. Run the tool, then use Download for the primary output or the JSON and CSV buttons when those structured exports are available.

Input contract

ItemRequirement
FormatJSON object
ExecutionLocal browser
Remote refsNot fetched

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