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POST
/
v1
/
chat
/
completions
Chat and Responses
curl --request POST \
  --url https://api.compose.market/v1/chat/completions \
  --header 'Content-Type: application/json' \
  --data '
{
  "model": "<string>",
  "messages": [
    {}
  ],
  "stream": true,
  "tools": [
    {}
  ],
  "tool_choice": {},
  "response_format": {},
  "input": {},
  "previous_response_id": "<string>",
  "modalities": [
    {}
  ]
}
'

Documentation Index

Fetch the complete documentation index at: https://docs.compose.market/llms.txt

Use this file to discover all available pages before exploring further.

Use these routes when you want native Compose receipts, raw x402 support, or Compose Key billing.

​
Routes

MethodPathStreamingDescription
POST/v1/chat/completionsYesOpenAI Chat Completions-shaped request and response.
POST/v1/responsesYesResponses-shaped input, tools, multimodal content, and stored response IDs.
GET/v1/responses/{id}NoRetrieve a stored response record.
GET/v1/responses/{id}/input_itemsNoReturn stored input items for a response.
POST/v1/responses/{id}/cancelNoCancel a stored response or async media job.
POST/api/inferenceYesLegacy alias for /v1/chat/completions.

​
Headers

​
Authorization
string
Bearer compose-... for Compose Key billing.
​
PAYMENT-SIGNATURE
string
Raw x402 payment signature for x402-aware clients.
​
x-x402-max-amount-wei
string
Maximum USDC atomic amount for raw x402 upto payments.

​
Chat body

​
model
string
required
Public catalog model ID.
​
messages
array
required
Non-empty OpenAI-style chat message array.
​
stream
boolean
Enables SSE streaming. Non-boolean values return 400 invalid_stream.
​
tools
array
OpenAI function tool definitions for models that support tool calling.
​
tool_choice
string | object
none, auto, required, or a named function choice.
​
response_format
object
Text, JSON object, or JSON schema response format when the provider supports it.

​
Responses body

​
model
string
required
Public catalog model ID.
​
input
string | array
required
Responses-style input. Required unless previous_response_id supplies history.
​
previous_response_id
string
Response ID to hydrate prior messages.
​
modalities
array
Requested output modalities.

​
Streaming events

Native streams send OpenAI-compatible data frames plus Compose events:
EventDescription
data: {...}Chat or Responses chunk.
event: compose.receiptIn-band settlement receipt before stream close.
event: compose.errorStructured Compose error frame.
data: [DONE]Stream terminator.