LLM API | Basic Completions

POST

https://api.piapi.ai/v1/chat/completions

INFO

Discount

PiAPI also provides different LLM API at cost effective pricing, sometimes at 25%~75% of their official pricing.

Availability

Given the steep discount, we sometimes face availability issues thus we always recommend developers to always have another back up API source ready - take advantage of our low pricing when you can, and when availability becomes a problem switch to a higher cost solution to maintain overall system up-time.

model name	pricing	Notes
gpt-4o-mini	input 1M tokens = $0.1125 output 1M tokens = $0.45	75% of OpenAI's official pricing
gpt-4o	input 1M tokens = $1.875 output 1M tokens = $7.5 Only for Creator Plan or Above	75% of OpenAI's official pricing, as the original OpenAI's API model gpt-4o.
gpt-4.1 and gpt-4.1-mini and gpt-4.1 nano	75% of OpenAI's official pricing, as the original OpenAI's API	75% of OpenAI's official pricing, as the original OpenAI's API
claude-3-7-sonnet-20250219	input 1M tokens = $2.25 output 1M tokens = $11.25 Only for Creator Plan or Above	75% of Anthropic's official pricing
claude-sonnet-4-20250514	input 1M tokens = $2.25 output 1M tokens = $11.25 Only for Creator Plan or Above	75% of Anthropic's official pricing
o3	75% of OpenAI's official pricing, as the original OpenAI's API	75% of OpenAI's official pricing, as the original OpenAI's API
gpt-4o-image	$0.02 per request	see 4o image generation api
gpt-image-1	same as openai official	see openai-official-pricing

Note:

OpenAI's input and output tokens, where 1k token roughly equals to 750 words. Thus 1 token roughly equates to 0.75 word.

The definition of minimum charge: if the actual token (input+output) usage for that particular completion is less than that value, we will round it that value.

Request

Header Params

Authorization

string

required

Your API KEY for authorization

Body Params application/json

model

string

required

The name of the model to be used

How to get Gizmo model name: Go to ChatGPT official website, explore the GPTs and enter chat with the GPT of your choice, you will see webpage address like https://chatgpt.com/g/g-gFt1ghYJl-logo-creator. Then the model name you should use is gpt-4-gizmo-g-gFt1ghYJl.

messages

array[string]

required

A list of messages comprising the conversation so far

functions

array[string]

optional

A list of functions the model may generate JSON inputs for.

function_call

string

optional

Controls how the model calls functions.

"none" means the model will not call a function and instead generates a message.

"auto" means the model can pick between generating a message or calling a function.

Specifying a particular function via {name:my_function} forces the model to call that function.

"none" is the default when no functions are present.

"auto" is the default if functions are present.

temperature

number

optional

Defaults to 1. What sampling temperature to use, between 0 and 2.

Higher values like 0.8 will make the output more random, while lower values like 0.2 will make it more focused and deterministic.

top_p

number

optional

Defaults to 1.

An alternative to sampling with temperature, called nucleus sampling, where the model considers the results of the tokens with top_p probability mass.

So 0.1 means only the tokens comprising the top 10% probability mass are considered.

integer

optional

Defaults to 1.

How many chat completion choices to generate for each input message.

stream

boolean

optional

Defaults to false.

If set, partial message deltas will be sent, like in ChatGPT.

Tokens will be sent as data-only server-sent events as they become available, with the stream terminated by a data:[none] message

stop

string | array

optional

Defaults to null.

Up to 4 sequences where the API will stop generating further tokens.

max_tokens

number

optional

Defaults to the maximum number of tokens to generate in the chat completion.

presence_penalty

number

optional

Defaults to 0.

Number between -2.0 and 2.0.

Positive values penalize new tokens based on whether they appear in the text so far, increasing the model's likelihood to talk about new topics.

frequency_penalty

number

optional

Defaults to 0.

Number between -2.0 and 2.0.

Positive values penalize new tokens based on their existing frequency in the text so far, decreasing the model's likelihood to repeat the same line verbatim.

logit_bias

string

optional

Defaults to null. Modify the likelihood of specified tokens appearing in the completion.

Example

//Request Example - No Streaming

curl https://api.piapi.ai/v1/chat/completions \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer API_KEY" \
  -d '{
    "model": "gpt-3.5-turbo",
    "messages": [
     {
        "role": "system",
        "content": "You are a helpful assistant."
      },
      {
        "role": "user",
        "content": "Hello!"
      }
    ]
  }'


  //Request Example - Streaming
  curl https://api.piapi.ai/v1/chat/completions \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer API_KEY" \
  -d '{
    "model": "gpt-3.5-turbo",
    "messages": [
      {
        "role": "system",
        "content": "You are a helpful assistant."
      },
      {
        "role": "user",
        "content": "Hello!"
      }
   ],
    "stream": true
  }'

Request samples

Shell

JavaScript

Java

Swift

PHP

Python

HTTP

Objective-C

Ruby

OCaml

Dart

curl --location --request POST 'https://api.piapi.ai/v1/chat/completions' \
--header 'Authorization;' \
--header 'Content-Type: application/json' \
--data-raw '//Request Example - No Streaming

curl https://api.piapi.ai/v1/chat/completions \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer API_KEY" \
  -d '\''{
    "model": "gpt-3.5-turbo",
    "messages": [
     {
        "role": "system",
        "content": "You are a helpful assistant."
      },
      {
        "role": "user",
        "content": "Hello!"
      }
    ]
  }'\''


  //Request Example - Streaming
  curl https://api.piapi.ai/v1/chat/completions \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer API_KEY" \
  -d '\''{
    "model": "gpt-3.5-turbo",
    "messages": [
      {
        "role": "system",
        "content": "You are a helpful assistant."
      },
      {
        "role": "user",
        "content": "Hello!"
      }
   ],
    "stream": true
  }'\'''

Responses

🟢200OK

application/json

Body

string

required

object

string

required

created

integer

required

model

string

required

choices

array [object {3}]

required

index

integer

optional

message

object

optional

finish_reason

string

optional

usage

object

required

prompt_tokens

integer

required

completion_tokens

integer

required

total_tokens

integer

required

Examples

Success- No StreamingSuccess-Steaming

{
    "id": "chatcmpl-83jZ61GDHtdlsFUzXDbpGeoU193Mj",
    "object": "chat.completion",
    "created": 1695900828,
    "model": "gpt-3.5-turbo",
    "choices": [
        {
            "index": 0,
            "message": {
                "role": "assistant",
                "content": "Hello! How can I assist you today?"
            },
            "finish_reason": "stop"
        }
    ],
    "usage": {
        "prompt_tokens": 19,
        "completion_tokens": 9,
        "total_tokens": 28
    }
}

🟠400Bad Request

🟠401Unauthorized

🔴500Server Error

Modified at 2025-07-06 07:41:40

GPT-4o Image Generation API

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LLM API | Basic Completions

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