Chat & Responses

Use the request format your application already understands. The format does not determine the underlying provider: an OpenAI-compatible request can still target a supported Claude, Gemini, Qwen, or other model.

Format	Route	Best for
OpenAI Chat Completions	`POST /v1/chat/completions`	Existing OpenAI SDK integrations
OpenAI Responses	`POST /v1/responses`	New OpenAI-style applications and tool use
Anthropic Messages	`POST /v1/messages`	Existing Anthropic SDK integrations
Native Anthropic	`/anthropic/v1/*`	Anthropic-specific endpoints or semantics

OpenAI-Compatible Chat

TypeScript
Python
cURL

import OpenAI from "openai";

const client = new OpenAI({
  baseURL: "https://api.inquantum.ai/v1",
  apiKey: process.env.PLANCK_API_KEY,
});

const response = await client.chat.completions.create({
  model: "gpt-4o-mini",
  messages: [
    { role: "user", content: "Explain vector search in one sentence." },
  ],
});

console.log(response.choices[0].message.content);

import os
from openai import OpenAI

client = OpenAI(
    base_url="https://api.inquantum.ai/v1",
    api_key=os.environ["PLANCK_API_KEY"],
)

response = client.chat.completions.create(
    model="gpt-4o-mini",
    messages=[{"role": "user", "content": "Explain vector search in one sentence."}],
)

print(response.choices[0].message.content)

curl https://api.inquantum.ai/v1/chat/completions \
  -H "Authorization: Bearer $PLANCK_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "gpt-4o-mini",
    "messages": [
      {"role": "user", "content": "Explain vector search in one sentence."}
    ]
  }'

Set stream: true to receive server-sent events. See Chat Completions for the complete request reference.

Responses API

curl https://api.inquantum.ai/v1/responses \
  -H "Authorization: Bearer $PLANCK_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "gpt-4o-mini",
    "input": "Explain vector search in one sentence."
  }'

See Responses API for supported request behavior.

Anthropic-Compatible Messages

The mapped Messages route accepts Anthropic-style inputs and returns an Anthropic-style response while retaining gateway routing, billing, and observability.

curl https://api.inquantum.ai/v1/messages \
  -H "Authorization: Bearer $PLANCK_API_KEY" \
  -H "Content-Type: application/json" \
  -H "anthropic-version: 2023-06-01" \
  -d '{
    "model": "claude-4.5-sonnet",
    "max_tokens": 256,
    "messages": [
      {"role": "user", "content": "Explain vector search in one sentence."}
    ]
  }'

Use /anthropic/v1/* only when you need a native Anthropic path that is not covered by the mapped Messages route.

Observability

Successful and failed generations appear in Requests with their model, provider, tokens, duration, cost, user, custom properties, and response status. Add your own user, session, or property headers when you need application-level attribution.

Configure routing and BYOK

Choose providers, supply provider keys, and configure fallbacks.

Getting Started

AI Gateway

Observability & Analytics

Prompt Management

Async Logging

Custom Logs

Chat & Responses

OpenAI-Compatible Chat

Responses API

Anthropic-Compatible Messages

Observability

Configure routing and BYOK

​OpenAI-Compatible Chat

​Responses API

​Anthropic-Compatible Messages

​Observability

Configure routing and BYOK

OpenAI-Compatible Chat

Responses API

Anthropic-Compatible Messages

Observability