Apertis Docs
Apertis Docs

Text Generation

Chat Completion

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/v1/chat/completions

HTTP Request

curl https://api.apertis.ai/v1/chat/completions \
    -H "Content-Type: application/json" \
    -H "Authorization: Bearer <APERTIS_API_KEY>" \
    -d '{
        "model": "<MODEL_ALIAS>",
        "messages": [
            {
                "role": "system",
                "content": "<MESSAGES>"
            }
        ]
    }'
  • <APERTIS_API_KEY>: Your API key
  • <MODEL_ALIAS>: The alias of the model to use
  • <MESSAGES>: The messages to send to the model

Optional Headers

Header Type Description
X-Timeout integer Total request timeout in milliseconds. Caps the entire request lifecycle including all channel retries. Range: 5,000–300,000 ms. Default: 60,000 ms (60s). See Request Timeout.

Optional Parameters

Parameter Type Description
temperature number Sampling temperature (0-2). Default: 1
max_tokens integer Maximum tokens in the response
top_p number Nucleus sampling threshold (0-1)
stream boolean Enable streaming. Default: false
compression object Context compression configuration

Context Compression

Add a compression object to automatically summarize older conversation history and reduce token usage for long conversations:

curl https://api.apertis.ai/v1/chat/completions \
    -H "Content-Type: application/json" \
    -H "Authorization: Bearer <APERTIS_API_KEY>" \
    -d '{
        "model": "gpt-4.1-mini",
        "messages": [{"role": "user", "content": "Hello!"}],
        "compression": {"enabled": true, "model": "gpt-4.1-mini"}
    }'

See Context Compression for full documentation.

Request Timeout

Use the X-Timeout header to limit the total time a request can take, including all internal channel retries. This prevents long waits when multiple upstream providers are slow or unavailable.

curl https://api.apertis.ai/v1/chat/completions \
    -H "Content-Type: application/json" \
    -H "Authorization: Bearer <APERTIS_API_KEY>" \
    -H "X-Timeout: 20000" \
    -d '{
        "model": "gemini-3-flash-preview",
        "messages": [{"role": "user", "content": "Hello!"}]
    }'
from openai import OpenAI

client = OpenAI(
    api_key="your-apertis-key",
    base_url="https://api.apertis.ai/v1"
)

response = client.chat.completions.create(
    model="gemini-3-flash-preview",
    messages=[{"role": "user", "content": "Hello!"}],
    extra_headers={"X-Timeout": "20000"}  # 20 seconds
)
Setting Value
Default 60,000 ms (60 seconds)
Minimum 5,000 ms (5 seconds)
Maximum 300,000 ms (5 minutes)

When the timeout is exceeded, the API returns HTTP 408 with diagnostic headers:

Header Description
X-Timeout-Attempts Number of upstream channels attempted
X-Timeout-Elapsed-Ms Actual elapsed time in milliseconds 
{
  "error": {
    "message": "Total request timeout (20000ms) exceeded after 3 channel attempts. Set X-Timeout header to adjust.",
    "type": "timeout",
    "code": "request_timeout"
  }
}

See also: Fallback Models for per-model fallback timeout configuration.