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POST
/
openai
/
v1
/
chat
/
completions
curl https://api.lumenfall.ai/openai/v1/chat/completions \
  -H "Authorization: Bearer $LUMENFALL_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "google/gemini-3-flash-preview",
    "messages": [
      {"role": "user", "content": "Why are capybaras so chill?"}
    ]
  }'

{
  "id": "chatcmpl-abc123",
  "object": "chat.completion",
  "created": 1702345678,
  "model": "google/gemini-3-flash-preview",
  "choices": [
    {
      "index": 0,
      "message": {
        "role": "assistant",
        "content": "Capybaras are remarkably calm animals for several reasons. As the largest rodents in the world, they have few natural predators in their South American habitats, which means they haven't evolved a strong flight-or-fight response. They're also highly social and semi-aquatic, spending much of their time lounging in warm water - which would make anyone relaxed!"
      },
      "finish_reason": "stop"
    }
  ],
  "usage": {
    "prompt_tokens": 14,
    "completion_tokens": 71,
    "total_tokens": 85
  }
}
Modern media applications don’t just generate images and videos — they also make dozens of LLM calls for prompting, captioning, moderation, and orchestration. Instead of juggling a separate provider or router for text, you can use the same Lumenfall SDK, API key, and base URL you already use for media generation. One platform, one bill, no context-switching.
Powered by OpenRouterText completions are routed through OpenRouter, giving you access to all hundreds of models available on their platform — from OpenAI, Google, Anthropic, Meta, Mistral, and many more providers. All OpenRouter features are fully supported. Use any model by passing its OpenRouter model identifier (e.g., google/gemini-3-flash-preview). You can optionally prefix with openrouter/ (e.g., openrouter/google/gemini-3-flash-preview), but it is not required.
OpenAI compatibilityThis endpoint implements the OpenAI Chat Completions API. You can use any OpenAI SDK by changing the base URL to https://api.lumenfall.ai/openai/v1.

​
Request body

You can include additional parameters not listed here. They will be passed through to the underlying provider.
​
model
string
required
The model to use. Pass any OpenRouter model identifier — for example, google/gemini-3-flash-preview or openai/gpt-5.4.
​
messages
array
required
A list of messages comprising the conversation. Each message has a role and content.
​
stream
boolean
default:"false"
If true, the response is sent as server-sent events (SSE). Partial message deltas are sent as data: {json} lines, ending with data: [DONE].
​
temperature
number
default:"1"
Sampling temperature between 0 and 2. Higher values make output more random, lower values make it more focused.
​
max_tokens
integer
The maximum number of tokens to generate.
​
top_p
number
default:"1"
Nucleus sampling parameter. Only consider tokens with cumulative probability up to this value.
​
frequency_penalty
number
default:"0"
Penalizes tokens based on their frequency in the text so far. Range: -2.0 to 2.0.
​
presence_penalty
number
default:"0"
Penalizes tokens based on whether they appear in the text so far. Range: -2.0 to 2.0.
​
stop
string | array
Up to 4 sequences where the model will stop generating.
​
tools
array
A list of tools the model may call. Currently only function type tools are supported.
​
tool_choice
string | object
Controls which tool the model calls. Options:
  • "none" - Do not call any tool
  • "auto" - Model decides whether to call a tool
  • "required" - Model must call a tool
  • {"type": "function", "function": {"name": "my_function"}} - Call a specific function
​
response_format
object
The format of the response. Set {"type": "json_object"} to enable JSON mode.
​
seed
integer
A seed for deterministic generation. Not all models support this.
​
user
string
A unique identifier representing your end-user.
​
logprobs
boolean
default:"false"
Whether to return log probabilities of the output tokens.
​
top_logprobs
integer
Number of most likely tokens to return at each position (0-20). Requires logprobs: true.
​
stream_options
object
Options for streaming responses.

​
Response

​
id
string
A unique identifier for the chat completion.
​
object
string
Always chat.completion.
​
created
integer
Unix timestamp of when the completion was created.
​
model
string
The model used for the completion.
​
choices
array
A list of chat completion choices.
​
usage
object
Token usage statistics for the request.

​
Streaming

When stream: true is set, the response is sent as server-sent events. Each event contains a chat.completion.chunk object with a delta field instead of message: 
data: {"id":"chatcmpl-abc123","object":"chat.completion.chunk","created":1702345678,"model":"google/gemini-3-flash-preview","choices":[{"index":0,"delta":{"role":"assistant"},"finish_reason":null}]}

data: {"id":"chatcmpl-abc123","object":"chat.completion.chunk","created":1702345678,"model":"google/gemini-3-flash-preview","choices":[{"index":0,"delta":{"content":"Capybaras"},"finish_reason":null}]}

data: {"id":"chatcmpl-abc123","object":"chat.completion.chunk","created":1702345678,"model":"google/gemini-3-flash-preview","choices":[{"index":0,"delta":{},"finish_reason":"stop"}]}

data: [DONE]

curl https://api.lumenfall.ai/openai/v1/chat/completions \
  -H "Authorization: Bearer $LUMENFALL_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "google/gemini-3-flash-preview",
    "messages": [
      {"role": "user", "content": "Why are capybaras so chill?"}
    ]
  }'

{
  "id": "chatcmpl-abc123",
  "object": "chat.completion",
  "created": 1702345678,
  "model": "google/gemini-3-flash-preview",
  "choices": [
    {
      "index": 0,
      "message": {
        "role": "assistant",
        "content": "Capybaras are remarkably calm animals for several reasons. As the largest rodents in the world, they have few natural predators in their South American habitats, which means they haven't evolved a strong flight-or-fight response. They're also highly social and semi-aquatic, spending much of their time lounging in warm water - which would make anyone relaxed!"
      },
      "finish_reason": "stop"
    }
  ],
  "usage": {
    "prompt_tokens": 14,
    "completion_tokens": 71,
    "total_tokens": 85
  }
}