JSON Extractor API Specification & Integration Reference

POST JSON Extractor API

/api/v1/ai/json-extractor

Extract structured JSON objects from unstructured raw text based on a custom schema.

Base Billing 1 Credit
Typical Response 1-3 s
Client Timeout 15-30 s (recommended)
Provider Fallback Automatic
JSON Contract Envelope v1

Architecture Role & AI Definition

JSON Extractor API provides low-latency, deterministic REST execution for production engineering workflows. It processes structured payloads with strict schema validation, returns uniform JSON envelopes, and is secured via SHA-256 API key authentication with atomic credit pre-authorization locks.

Production Reliability Guidelines

1. Strict Timeout Windows

Configure a hard client timeout of 5 to 8 seconds. If network latency spikes, cancel connection to avoid holding open sockets in worker pools.

2. Exponential Backoff with Jitter

Upon receiving 429 Rate Limit or transient 5xx, pause with exponential backoff:
wait = min(max_backoff, base * 2^attempt + jitter).

3. Atomic Pre-Auth Locks

RSFlowHub acquires an atomic lock verifying base credits before model invocation. If validation fails, zero credits are deducted.

Request Body Parameters

Field Type Required Description
text string Required The raw unstructured text containing data to be extracted (Max: 20,000 characters).
schema object Optional Optional JSON object defining the key-value schema structure to guide the extraction.
custom_instructions string Optional Optional text describing custom formatting, filtering, or sanitization rules (Max: 1,000 characters).
allow_large_text boolean Optional Optional flag. Set to true to raise the maximum text size limit to 100,000 characters (charges 1 extra credit per 10k characters above 20k).
Important Note on Credit Usage

The standard request limit is 20,000 characters (costs 3 base credits). If you need to process larger texts (up to 100,000 characters), you must explicitly set "allow_large_text": true in the request payload. Each additional 10,000 characters above the 20,000 threshold will consume 1 extra credit.


Example Request

JSON Request
{
  "text": "The patient John Doe is 34 years old and has been diagnosed with mild flu. He was admitted on 2026-06-15.",
  "schema": {
    "patient_name": "string",
    "patient_age": "integer",
    "diagnosis": "string",
    "admission_date": "string"
  },
  "custom_instructions": "Capitalize the diagnosis and format the date as YYYY-MM-DD."
}
curl-trigger.sh cURL
curl -X POST https://rsflowhub.com/api/v1/ai/json-extractor \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "text": "The patient John Doe is 34 years old and has been diagnosed with mild flu. He was admitted on 2026-06-15.",
    "schema": {
      "patient_name": "string",
      "patient_age": "integer",
      "diagnosis": "string",
      "admission_date": "string"
    },
    "custom_instructions": "Capitalize the diagnosis and format the date as YYYY-MM-DD."
  }'

Example Response

response.json JSON Response
200 OK
{
  "success": true,
  "request_id": "req_7f3a9c2d1e4b8a6f",
  "data": {
    "result": {
      "extracted_data": {
        "patient_name": "John Doe",
        "patient_age": 34,
        "diagnosis": "MILD FLU",
        "admission_date": "2026-06-15"
      },
      "schema_conforms": true,
      "parsed": true,
      "raw_content": "{\n  \"patient_name\": \"John Doe\",\n  \"patient_age\": 34,\n  \"diagnosis\": \"MILD FLU\",\n  \"admission_date\": \"2026-06-15\"\n}"
    }
  },
  "meta": {
    "version": "v1",
    "timestamp": "2026-09-27T12:34:56+00:00"
  }
}

API Request Example

Use the cURL snippet below to test the endpoint.

curl-trigger.sh cURL
curl -X POST 'https://rsflowhub.com/api/v1/ai/json-extractor' \
  -H 'Authorization: Bearer YOUR_API_KEY' \
  -H 'Content-Type: application/json' \
  -d '{
    "text": "The patient John Doe is 34 years old and has been diagnosed with mild flu. He was admitted on 2026-06-15.",
    "schema": {
        "patient_name": "string",
        "patient_age": "integer",
        "diagnosis": "string",
        "admission_date": "string"
    },
    "custom_instructions": "Capitalize the diagnosis and format the date as YYYY-MM-DD."
}'

Want to try it without code? Test this request in the live Playground.

Use Structured Output Mode
Always provide a schema parameter to guide the model. It ensures the response conforms exactly to your backend data models.

Common Failure Modes & Troubleshooting Matrix

HTTP Code Error Code Root Cause Recommended Remediation
400 bad_request Malformed JSON syntax or missing required top-level parameters. Validate JSON payload with Content-Type: application/json and ensure all required fields are present.
401 unauthorized Missing, revoked, or incorrectly formatted x-api-key header. Verify API key exists in Dashboard → API Keys and pass in x-api-key or Authorization: Bearer.
402 insufficient_credits Account credit balance is lower than the base required credits (2 credits). Top up credits in billing settings or enable auto-recharge to prevent pipeline interruption.
422 validation_error Input failed parameter constraints (e.g., character length exceeded or invalid array types). Review parameters table above and adjust payload length, types, or structure accordingly.
429 rate_limit_exceeded Concurrency limit (60 requests/minute default) reached for this endpoint key. Back off and retry using the timestamp in Retry-After response header, or batch requests.

Technical Q&A (FAQ)

Each JSON Extractor API call costs 2 base credits, plus about 1 credit per 1,000 input characters and 1 credit per 500 output characters. Failed calls are not charged.

The text field accepts up to 20,000 characters per request. Larger inputs return a 422 validation error, so split long content into chunks.

JSON Extractor API runs on Google Gemini (gemini-2.5-flash), with automatic fallback to OpenAI (gpt-4.1-mini) if the primary provider fails or rate-limits. Models are tuned per task, so your integration does not change when we upgrade them.

Yes. Identical requests within 24 hours are answered from cache, which is faster and free or discounted in credits.

Most requests complete in 1 to 3 seconds; set a client timeout of 15 to 30 seconds to cover long inputs. On HTTP 429, wait for the Retry-After delay. Retry network errors once or twice with exponential backoff and jitter.

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