Error Codes

HTTP status codes and error responses

SilentAPI returns HTTP status codes. Error responses follow the format of the request endpoint.

HTTP Status Codes

Code	Meaning	What to Do
200	Success	Process the response
400	Bad request	Check the request body, model name, and parameters
401	Missing API key	Send your API key in an accepted header
402	Insufficient credits	Add credits or increase the API key budget
403	Forbidden	API access may be disabled for your account
404	Service not found	The model ID does not exist
413	Input too large	Reduce the request size or image dimensions
415	Unsupported media type	Use application/json or multipart/form-data
422	Input rejected	Check the file, encryption, and request parameters
429	Rate limited	Wait and retry, or reduce request frequency
500	Internal error	Retry the request, contact support if it persists
502	Service error	The model returned an error, fallback may apply
503	Service unavailable	The service is temporarily disabled or overloaded

Error Response Formats

OpenAI Style

{
  "error": {
    "message": "Insufficient credits",
    "type": "silentapi_error"
  }
}

Anthropic Style

{
  "type": "error",
  "error": {
    "type": "api_error",
    "message": "Insufficient credits"
  }
}

Gemini Style

{
  "error": {
    "code": 402,
    "message": "Insufficient credits",
    "status": "SILENTAPI_ERROR"
  }
}

Common Error Messages

Message	Cause
Insufficient credits	The balance cannot cover the request or is zero.
This model doesn't exist.	The model ID is unknown and has no compatible match.
Prompt is required.	The request prompt is missing.
This account has reached its internal safety limit. Please contact contact@silentapi.com if you need this raised.	The account API minute limit was reached.
This API key has reached its monthly budget.	The key budget was reached. Change it on the Keys page.
This service is temporarily disabled.	Select another service.
The service is busy. Try again shortly.	The service or a shared quota is busy. A 429 response can include `Retry-After`.
The service could not complete the request. Try again shortly.	The service failed during the request.
The request was not accepted. Check the parameters and try again.	The request has invalid parameters.
The request is too large.	The request is larger than the endpoint allows.
The request was blocked by a content filter.	The request was blocked by a content filter.
The input is longer than the model context.	The input is longer than the model context.
Please wait before trying again	An account media operation limit was reached.
API key is required	No accepted API key was sent.
Invalid API key	The API key is not valid.
API key has expired	The key has passed its expiry date.
API key is disabled	The key is disabled.
API access is disabled for this account.	API access is disabled.
Insufficient credits for the requested maximum usage.	The balance cannot cover the request hold.
This model is not available right now.	The model has no active price.
Service is not configured.	The service cannot accept requests.
Request body is not valid JSON.	Correct the JSON body.
Request body is too large.	Reduce the encoded request body.
Request body is not valid form data.	Correct the multipart form.
A file is required.	Send a file, data URL, or supported HTTPS URL.
Image format is required.	Set format for image conversion.
Input is required.	Send nonempty moderation input.
This model does not support OCR.	Select an OCR model.
This model does not support moderation.	Select a moderation model.
This model does not create music.	Select a music model.
The lookup service is unavailable.	Retry after the wait time in Retry-After.
Enter a valid IP address.	The lookup IP address is invalid.
Enter a valid email address.	The email lookup input is missing.
Too many requests. Try again in one minute.	The status endpoint limit was reached. Wait 60 seconds.

Case	Status	Notes
The service is busy	429	Includes `Retry-After: 5`
A shared service quota is reached	429	`Retry-After` gives the wait time of that quota
An account limit is reached	429	`Retry-After` can be absent
The service rejects the input	400 or 422	Check the request parameters
The input is too large	413	Reduce the request size
Content filter or context error	Mapped from the failed request	The message names the cause

SilentAPI does not return error details from the service.

Old Model IDs

Supported old model IDs use a configured replacement or model family match. An unknown ID with no match returns 404. The response names the model that served the request.

The response tells you when this happens:

"silentapi": {
    "cost": 0.0412,
    "fallback": null,
    "model": "gpt-image-2.5-flare",
    "model_name": "GPT Image 2.5 Flare",
    "requested_model": "stable-image-ultra",
    "substituted": true,
    "notice": "stable-image-ultra is no longer offered. SilentAPI served this request with GPT Image 2.5 Flare, the closest current model."
}

These headers carry the same facts:

Header	Meaning
X-SilentAPI-Model	ID of the model that served the request
X-SilentAPI-Substituted-For	Requested model ID. Only present when another model served the request.

Audio responses have no JSON body, so read the headers there. See Fallbacks for each field of the silentapi object. A 404 means the ID has no close match. Check the Services page for the current list.

Media Error Messages

Media endpoints can return these fixed messages:

Message	Meaning
Forbidden.	Internal media authentication failed.
The input is not valid.	The request body or method is not valid.
The media options are not valid.	An option has the wrong type or value.
The file is too large.	The file or image dimensions exceed the limit.
This input format is not supported.	The file type is not supported.
The file could not be processed.	The media parser could not read the file.
Encrypted files are not supported.	The file is encrypted.
Lossless output is not available for this format.	The selected output format cannot be lossless.
Only English is available for this OCR model.	OCR accepts English OCR data only.
The page selection is not valid.	The page list or range is invalid.
A maximum of 50 pages is allowed.	The selected OCR pages exceed the limit.
The media service could not complete the request.	An internal media failure occurred.