GPT-5 Chat is a GPT-5 snapshot from OpenAI designed for ChatGPT-style conversational experiences. It supports text and image inputs with text output, a 128,000-token context window, and up to 16,384 output tokens. It is suitable for chat assistants, product Q&A, customer support, content generation, document summarization, image understanding, tool-based workflows, and general AI assistant scenarios that require natural, responsive, and reliable conversation quality.
Create chat completion
All API requests must be authenticated using a Bearer token in the Authorization header. Please ensure your API key is active.Authorization: Bearer sk-xxxxxx
These parameters come from the selected model form_schema. Switching models updates this list and the request example.
system_prompt?stringGlobal instructions or persona for the model.
prompt*stringimage_urls?arraySupports multi-image understanding (optional).
image_detail?stringverbosity?stringControls how verbose the response is.
temperature?numberHigher values make output more random, lower more deterministic.
top_p?numberNucleus sampling threshold; an alternative to temperature.
presence_penalty?numberIncreases the tendency to talk about new topics.
frequency_penalty?numberReduces the likelihood of repeating the same text verbatim.
seed?numberA fixed seed yields more reproducible results (optional).
max_completion_tokens?numberresponse_format?stringstream?booleanid?stringParameter description for Id
object?stringParameter description for Object
created?integerParameter description for Created
model?stringModel ID used
choices?arrayParameter description for Choices
usage?objectParameter description for Usage
prompt_tokens?integerParameter description for Prompt Tokens
completion_tokens?integerParameter description for Completion Tokens
total_tokens?integerParameter description for Total Tokens
prompt_tokens_details?objectParameter description for Prompt Tokens Details
completion_tokens_details?objectParameter description for Completion Tokens Details
system_fingerprint?stringParameter description for System Fingerprint
error?objectParameter description for Error
message?stringError Message
type?stringError Type
param?stringRelated Parameters
code?stringError Code
error?objectParameter description for Error
message?stringError Message
type?stringError Type
param?stringRelated Parameters
code?stringError Code