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Error Handling

The Predexon API uses standard HTTP status codes and returns consistent error responses to help you handle issues gracefully.

Error Response Format

All errors return a JSON object with error and message fields:

Code
 
{
  "error": "Bad Request",
  "message": "Invalid parameter: limit must be between 1 and 100"
}

HTTP Status Codes

Status Code	Error Type	Description
400	Bad Request	Invalid parameters or malformed request
401	Unauthorized	Missing or invalid API key
403	Forbidden	API key doesn't have access to this resource
404	Not Found	Resource doesn't exist (market, wallet, etc.)
422	Validation Error	Request validation failed
429	Too Many Requests	Rate limit exceeded
500	Internal Server Error	Something went wrong on our end
503	Service Unavailable	Service temporarily unavailable

Common Error Scenarios

Authentication Errors (401)

Code
 
curl -X GET "https://api.predexon.com/v1/polymarket/markets/active" \
  -H "Authorization: Bearer invalid_key"

Code
 
{
  "error": "Unauthorized",
  "message": "Invalid API key"
}

Invalid Parameters (400)

Code
 
curl -X GET "https://api.predexon.com/v1/polymarket/markets/active?limit=500"

Code
 
{
  "error": "Bad Request",
  "message": "limit must be between 1 and 100"
}

Resource Not Found (404)

Code
 
curl -X GET "https://api.predexon.com/v1/matching-markets?polymarket_market_slug=nonexistent-market"

Code
 
{
  "error": "Not Found",
  "message": "Market not found: nonexistent-market"
}

Rate Limit Exceeded (429)

Code
 
{
  "error": "Too Many Requests",
  "message": "Rate limit exceeded. Please wait before making more requests."
}

Validation Errors (422)

For complex validation failures, the response includes details:

Code
 
{
  "detail": [
    {
      "loc": ["query", "granularity"],
      "msg": "field required",
      "type": "value_error.missing"
    }
  ]
}

Handling Errors in Code

Python

Code
 
import requests

def get_markets():
    response = requests.get(
        "https://api.predexon.com/v1/polymarket/markets/active",
        headers={"Authorization": f"Bearer {API_KEY}"},
        params={"limit": 10}
    )

    if response.status_code == 200:
        return response.json()
    elif response.status_code == 401:
        raise Exception("Invalid API key")
    elif response.status_code == 429:
        retry_after = response.headers.get("RateLimit-Reset", 60)
        raise Exception(f"Rate limited. Retry after {retry_after}s")
    elif response.status_code == 400:
        error = response.json()
        raise Exception(f"Bad request: {error['message']}")
    else:
        response.raise_for_status()

JavaScript / TypeScript

Code
 
async function getMarkets() {
  const response = await fetch(
    "https://api.predexon.com/v1/polymarket/markets/active?limit=10",
    {
      headers: { Authorization: `Bearer ${API_KEY}` },
    }
  );

  if (response.ok) {
    return await response.json();
  }

  const error = await response.json();

  switch (response.status) {
    case 401:
      throw new Error("Invalid API key");
    case 429:
      const retryAfter = response.headers.get("RateLimit-Reset") || 60;
      throw new Error(`Rate limited. Retry after ${retryAfter}s`);
    case 400:
      throw new Error(`Bad request: ${error.message}`);
    default:
      throw new Error(`API error: ${response.status}`);
  }
}

Best Practices

1. Always check status codes - Don't assume requests succeed
2. Parse error messages - They contain useful debugging information
3. Handle 429s gracefully - Implement retry logic with backoff
4. Log errors - Include the full error response for debugging
5. Validate inputs client-side - Catch obvious errors before making requests

Getting Help

If you encounter unexpected errors:

1. Check the API Reference for correct parameter usage
2. Verify your API key is valid at predexon.com
3. Join our Discord for support
4. Email [email protected] with error details