> For clean Markdown of any page, append .md to the page URL. > For a complete documentation index, see https://docs.milliseconds.ai/llms.txt. > For AI client integration (Claude Code, Cursor, etc.), connect to the MCP server at https://docs.milliseconds.ai/_mcp/server. # OpenAI-compatible chat completions POST https://api.milliseconds.ai/v1/chat/completions Content-Type: application/json Drop-in for OpenAI clients with `model: "decision-machine-1"`. Two modes: `response_format: { type: "json_schema" }` extracts the schema from the user messages and returns the JSON as the assistant content; `tools` picks a tool and fills its arguments (function calling). Plain chat is rejected with 400. `stream: true` returns one chunk then \[DONE]. Reference: https://docs.milliseconds.ai/api/openai/chat-completions ## Authentication - `Authorization` header (bearer token, required) — A milliseconds API key, test\_sk-\{namespace}-\{entropy} or prod\_sk-\{namespace}-\{entropy}. Every /v1 route requires it. ## Request ### Body (application/json) This endpoint expects a ChatCompletionRequest. - `model` (string, required) - `messages` (list of ChatCompletionRequestMessagesItems, required) - `response_format` (ChatCompletionRequestResponseFormat, optional) - `tools` (list of ChatCompletionRequestToolsItems, optional) - `tool_choice` (ChatCompletionRequestToolChoice, optional) - `stream` (boolean, optional) ## Response ### 200 Completion - `id` (string, required) - `object` ("chat.completion", required) - `created` (integer, required) - `model` (string, required) - `choices` (list of ChatCompletionResponseChoicesItems, required) - `usage` (ChatCompletionResponseUsage, required) ## Errors ### 400 Bad Request Error Invalid or unsupported request - `error` (ErrorError, required) ## Types ### ChatCompletionRequestMessagesItems - `role` (enum, required) - Allowed values: `system`, `user`, `assistant`, `tool`, `developer` - `content` (ChatCompletionRequestMessagesItemsContent, optional, nullable) ### ChatCompletionRequestResponseFormat - ChatCompletionRequestResponseFormat0 - ChatCompletionRequestResponseFormat1 - ChatCompletionRequestResponseFormat2 ### ChatCompletionRequestToolsItems - `type` ("function", required) - `function` (ChatCompletionRequestToolsItemsFunction, required) ### ChatCompletionRequestToolChoice - enum - Allowed values: `none`, `auto`, `required` - ChatCompletionRequestToolChoice1 ### ChatCompletionResponseChoicesItems - `index` (integer, required) - `message` (ChatCompletionResponseChoicesItemsMessage, required) - `finish_reason` (enum, required) - Allowed values: `stop`, `tool_calls` ### ChatCompletionResponseUsage - `prompt_tokens` (integer, required) - `completion_tokens` (integer, required) - `total_tokens` (integer, required) ### ErrorError - `code` (string, required) - `message` (string, required) ### ChatCompletionRequestMessagesItemsContent - string - list of ChatCompletionRequestMessagesItemsContentOneOf1Items ### ChatCompletionRequestResponseFormat0 - `type` ("json_schema", required) - `json_schema` (ChatCompletionRequestResponseFormatOneOf0JsonSchema, required) ### ChatCompletionRequestResponseFormat1 - `type` ("json_object", required) ### ChatCompletionRequestResponseFormat2 - `type` ("text", required) ### ChatCompletionRequestToolsItemsFunction - `name` (string, required) - `description` (string, optional) - `parameters` (map from string to any, optional) ### ChatCompletionRequestToolChoice1 - `type` ("function", required) - `function` (ChatCompletionRequestToolChoiceOneOf1Function, required) ### ChatCompletionResponseChoicesItemsMessage - `role` ("assistant", required) - `content` (string, required, nullable) - `tool_calls` (list of ChatCompletionResponseChoicesItemsMessageToolCallsItems, optional) ### ChatCompletionRequestMessagesItemsContentOneOf1Items - `type` (string, required) - `text` (string, optional) - `image_url` (ChatCompletionRequestMessagesItemsContentOneOf1ItemsImageUrl, optional) ### ChatCompletionRequestResponseFormatOneOf0JsonSchema - `schema` (map from string to any, required) - `name` (string, optional) - `strict` (boolean, optional) ### ChatCompletionRequestToolChoiceOneOf1Function - `name` (string, required) ### ChatCompletionResponseChoicesItemsMessageToolCallsItems - `id` (string, required) - `type` ("function", required) - `function` (ChatCompletionResponseChoicesItemsMessageToolCallsItemsFunction, required) ### ChatCompletionRequestMessagesItemsContentOneOf1ItemsImageUrl - `url` (string, required) - `detail` (string, optional) ### ChatCompletionResponseChoicesItemsMessageToolCallsItemsFunction - `name` (string, required) - `arguments` (string, required) ## Examples **Request** ```json { "model": "decision-machine-1", "messages": [ { "role": "user", "content": "Book me a table for 4 at Nobu on Friday at 8pm" } ], "response_format": { "json_schema": { "name": "booking", "schema": { "properties": { "day": { "type": "string" }, "party_size": { "type": "integer" }, "restaurant": { "type": "string" }, "time": { "type": "string" } }, "type": "object" } }, "type": "json_schema" } } ``` **Response** ```json { "id": "chatcmpl-7f3a1c2e9b8d4e6f0a1b2c3d", "object": "chat.completion", "created": 1789000000, "model": "decision-machine-1", "choices": [ { "index": 0, "message": { "role": "assistant", "content": "{\"restaurant\":\"Nobu\",\"party_size\":4,\"day\":\"Friday\",\"time\":\"8pm\"}" }, "finish_reason": "stop" } ], "usage": { "prompt_tokens": 12, "completion_tokens": 16, "total_tokens": 28 } } ``` **SDK Code** ```python openai_chatCompletions_example import requests url = "https://api.milliseconds.ai/v1/chat/completions" payload = { "model": "decision-machine-1", "messages": [ { "role": "user", "content": "Book me a table for 4 at Nobu on Friday at 8pm" } ], "response_format": { "json_schema": { "name": "booking", "schema": { "properties": { "day": { "type": "string" }, "party_size": { "type": "integer" }, "restaurant": { "type": "string" }, "time": { "type": "string" } }, "type": "object" } }, "type": "json_schema" } } headers = { "Authorization": "Bearer ", "Content-Type": "application/json" } response = requests.post(url, json=payload, headers=headers) print(response.json()) ``` ```javascript openai_chatCompletions_example const url = 'https://api.milliseconds.ai/v1/chat/completions'; const options = { method: 'POST', headers: {Authorization: 'Bearer ', 'Content-Type': 'application/json'}, body: '{"model":"decision-machine-1","messages":[{"role":"user","content":"Book me a table for 4 at Nobu on Friday at 8pm"}],"response_format":{"json_schema":{"name":"booking","schema":{"properties":{"day":{"type":"string"},"party_size":{"type":"integer"},"restaurant":{"type":"string"},"time":{"type":"string"}},"type":"object"}},"type":"json_schema"}}' }; try { const response = await fetch(url, options); const data = await response.json(); console.log(data); } catch (error) { console.error(error); } ``` ```go openai_chatCompletions_example package main import ( "fmt" "strings" "net/http" "io" ) func main() { url := "https://api.milliseconds.ai/v1/chat/completions" payload := strings.NewReader("{\n \"model\": \"decision-machine-1\",\n \"messages\": [\n {\n \"role\": \"user\",\n \"content\": \"Book me a table for 4 at Nobu on Friday at 8pm\"\n }\n ],\n \"response_format\": {\n \"json_schema\": {\n \"name\": \"booking\",\n \"schema\": {\n \"properties\": {\n \"day\": {\n \"type\": \"string\"\n },\n \"party_size\": {\n \"type\": \"integer\"\n },\n \"restaurant\": {\n \"type\": \"string\"\n },\n \"time\": {\n \"type\": \"string\"\n }\n },\n \"type\": \"object\"\n }\n },\n \"type\": \"json_schema\"\n }\n}") req, _ := http.NewRequest("POST", url, payload) req.Header.Add("Authorization", "Bearer ") req.Header.Add("Content-Type", "application/json") res, _ := http.DefaultClient.Do(req) defer res.Body.Close() body, _ := io.ReadAll(res.Body) fmt.Println(res) fmt.Println(string(body)) } ``` ```ruby openai_chatCompletions_example require 'uri' require 'net/http' url = URI("https://api.milliseconds.ai/v1/chat/completions") http = Net::HTTP.new(url.host, url.port) http.use_ssl = true request = Net::HTTP::Post.new(url) request["Authorization"] = 'Bearer ' request["Content-Type"] = 'application/json' request.body = "{\n \"model\": \"decision-machine-1\",\n \"messages\": [\n {\n \"role\": \"user\",\n \"content\": \"Book me a table for 4 at Nobu on Friday at 8pm\"\n }\n ],\n \"response_format\": {\n \"json_schema\": {\n \"name\": \"booking\",\n \"schema\": {\n \"properties\": {\n \"day\": {\n \"type\": \"string\"\n },\n \"party_size\": {\n \"type\": \"integer\"\n },\n \"restaurant\": {\n \"type\": \"string\"\n },\n \"time\": {\n \"type\": \"string\"\n }\n },\n \"type\": \"object\"\n }\n },\n \"type\": \"json_schema\"\n }\n}" response = http.request(request) puts response.read_body ``` ```java openai_chatCompletions_example import com.mashape.unirest.http.HttpResponse; import com.mashape.unirest.http.Unirest; HttpResponse response = Unirest.post("https://api.milliseconds.ai/v1/chat/completions") .header("Authorization", "Bearer ") .header("Content-Type", "application/json") .body("{\n \"model\": \"decision-machine-1\",\n \"messages\": [\n {\n \"role\": \"user\",\n \"content\": \"Book me a table for 4 at Nobu on Friday at 8pm\"\n }\n ],\n \"response_format\": {\n \"json_schema\": {\n \"name\": \"booking\",\n \"schema\": {\n \"properties\": {\n \"day\": {\n \"type\": \"string\"\n },\n \"party_size\": {\n \"type\": \"integer\"\n },\n \"restaurant\": {\n \"type\": \"string\"\n },\n \"time\": {\n \"type\": \"string\"\n }\n },\n \"type\": \"object\"\n }\n },\n \"type\": \"json_schema\"\n }\n}") .asString(); ``` ```php openai_chatCompletions_example request('POST', 'https://api.milliseconds.ai/v1/chat/completions', [ 'body' => '{ "model": "decision-machine-1", "messages": [ { "role": "user", "content": "Book me a table for 4 at Nobu on Friday at 8pm" } ], "response_format": { "json_schema": { "name": "booking", "schema": { "properties": { "day": { "type": "string" }, "party_size": { "type": "integer" }, "restaurant": { "type": "string" }, "time": { "type": "string" } }, "type": "object" } }, "type": "json_schema" } }', 'headers' => [ 'Authorization' => 'Bearer ', 'Content-Type' => 'application/json', ], ]); echo $response->getBody(); ``` ```csharp openai_chatCompletions_example using RestSharp; var client = new RestClient("https://api.milliseconds.ai/v1/chat/completions"); var request = new RestRequest(Method.POST); request.AddHeader("Authorization", "Bearer "); request.AddHeader("Content-Type", "application/json"); request.AddParameter("application/json", "{\n \"model\": \"decision-machine-1\",\n \"messages\": [\n {\n \"role\": \"user\",\n \"content\": \"Book me a table for 4 at Nobu on Friday at 8pm\"\n }\n ],\n \"response_format\": {\n \"json_schema\": {\n \"name\": \"booking\",\n \"schema\": {\n \"properties\": {\n \"day\": {\n \"type\": \"string\"\n },\n \"party_size\": {\n \"type\": \"integer\"\n },\n \"restaurant\": {\n \"type\": \"string\"\n },\n \"time\": {\n \"type\": \"string\"\n }\n },\n \"type\": \"object\"\n }\n },\n \"type\": \"json_schema\"\n }\n}", ParameterType.RequestBody); IRestResponse response = client.Execute(request); ``` ```swift openai_chatCompletions_example import Foundation let headers = [ "Authorization": "Bearer ", "Content-Type": "application/json" ] let parameters = [ "model": "decision-machine-1", "messages": [ [ "role": "user", "content": "Book me a table for 4 at Nobu on Friday at 8pm" ] ], "response_format": [ "json_schema": [ "name": "booking", "schema": [ "properties": [ "day": ["type": "string"], "party_size": ["type": "integer"], "restaurant": ["type": "string"], "time": ["type": "string"] ], "type": "object" ] ], "type": "json_schema" ] ] as [String : Any] let postData = JSONSerialization.data(withJSONObject: parameters, options: []) let request = NSMutableURLRequest(url: NSURL(string: "https://api.milliseconds.ai/v1/chat/completions")! as URL, cachePolicy: .useProtocolCachePolicy, timeoutInterval: 10.0) request.httpMethod = "POST" request.allHTTPHeaderFields = headers request.httpBody = postData as Data let session = URLSession.shared let dataTask = session.dataTask(with: request as URLRequest, completionHandler: { (data, response, error) -> Void in if (error != nil) { print(error as Any) } else { let httpResponse = response as? HTTPURLResponse print(httpResponse) } }) dataTask.resume() ```