Text OpenAI

GPT API

Use the GPT API via RunAPI with a model skill, unified auth, and pay-as-you-go pricing.

runapi.ai
# Base URL
https://runapi.ai

# Endpoints
POST /v1/chat/completions
POST /v1/responses
POST /v1/messages
POST /v1beta/models/{model}:generateContent
POST /v1beta/models/{model}:streamGenerateContent
POST /v1/live
curl https://runapi.ai/v1/chat/completions \
  -H "Authorization: Bearer $RUNAPI_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
  "model": "gpt-live-1",
  "messages": [
    {
      "role": "user",
      "content": "Analyze this quarterly revenue data and produce a summary with key trends, anomalies, and three recommendations."
    }
  ]
}'
from openai import OpenAI

client = OpenAI(
    base_url="https://runapi.ai/v1",
    api_key="your-runapi-key"
)

response = client.chat.completions.create(
    model="gpt-live-1",
    messages=[{"role": "user", "content": "Analyze this quarterly revenue data and produce a summary with key trends, anomalies, and three recommendations."}]
)
import OpenAI from "openai";

const client = new OpenAI({
  baseURL: "https://runapi.ai/v1",
  apiKey: "your-runapi-key"
});

const response = await client.chat.completions.create({
  model: "gpt-live-1",
  messages: [{ role: "user", content: "Analyze this quarterly revenue data and produce a summary with key trends, anomalies, and three recommendations." }]
});
https://runapi.ai 6 endpoints
OVERVIEW

About GPT

GPT is OpenAI's flagship large language model series, with the GPT-5 family delivering state-of-the-art performance in chat, code generation, and multi-step reasoning. Available in multiple capability tiers.

Provider
OpenAI
Modality
Text

GPT API endpoints

EndpointProtocol
POST /v1/chat/completionsOpenAI compatible
POST /v1/responsesOpenAI Responses
POST /v1/messagesAnthropic compatible
POST /v1beta/models/{model}:generateContentGemini generateContent
POST /v1beta/models/{model}:streamGenerateContentGemini streamGenerateContent
POST /v1/liveOpenAI Live

Available Versions

Variant Billing Pricing
codex-auto-review 1K tokens Input $0.20 / 1M tokens | Output $1.20 / 1M tokens View →
gpt-4o-mini 1K tokens Input $0.15 / 1M tokens | Output $0.60 / 1M tokens View →
gpt-5-pro 1K tokens Input $7.50 / 1M tokens | Output $60.00 / 1M tokens View →
gpt-5.2 1K tokens Input $1.75 / 1M tokens | Output $14.00 / 1M tokens View →
gpt-5.2-pro 1K tokens Retired View →
gpt-5.3-codex 1K tokens Retired View →
gpt-5.3-codex-spark 1K tokens Retired View →
gpt-5.4 1K tokens Input $2.50 / 1M tokens | Output $15.00 / 1M tokens View →
gpt-5.4-mini 1K tokens Input $0.75 / 1M tokens | Output $4.50 / 1M tokens View →
gpt-5.4-nano 1K tokens Input $0.20 / 1M tokens | Output $1.25 / 1M tokens View →
gpt-5.4-pro 1K tokens Retired View →
gpt-5.5 1K tokens Input $5.00 / 1M tokens | Output $30.00 / 1M tokens View →
gpt-5.5-pro 1K tokens Retired View →
gpt-5.6-luna 1K tokens Input $0.20-$0.40 / 1M tokens | Output $1.20-$1.80 / 1M tokens View →
gpt-5.6-sol 1K tokens Input $5.00 / 1M tokens | Output $30.00 / 1M tokens View →
gpt-5.6-terra 1K tokens Input $2.00-$4.00 / 1M tokens | Output $12.00-$18.00 / 1M tokens View →
gpt-6-astra 1K tokens Input $5.00-$10.00 / 1M tokens | Output $25.00-$37.50 / 1M tokens View →
gpt-6-luna 1K tokens Input $0.06-$0.12 / 1M tokens | Output $0.30-$0.45 / 1M tokens View →
gpt-6-sol 1K tokens Input $1.20-$2.40 / 1M tokens | Output $6.00-$9.00 / 1M tokens View →
gpt-6.1-sol 1K tokens Input $1.00-$2.00 / 1M tokens | Output $5.00-$7.50 / 1M tokens View →
gpt-live-1 minute $0.05 View →
PRICING

GPT Pricing

Endpoint Resolution Duration Price
chat_completion — — Input $0.20 / 1M tokens | Output $1.20 / 1M tokens
response — — Input $0.20 / 1M tokens | Output $1.20 / 1M tokens

Prices shown for codex-auto-review. Other variants retain their own endpoint pricing.

Agent integration

Run GPT From an Agent

HOW IT WORKS

Get Started with GPT

  1. Create an API key

    Sign up and generate an API key from the dashboard.

  2. Pick a version

    Choose the version that best matches your quality and cost requirements.

  3. Send a request

    Submit your prompt and parameters to the model's documented endpoint.

  4. Get your result

    Poll the task or set a webhook, then download the completed output.

CONTEXT

About GPT on RunAPI

GPT is OpenAI's frontier LLM family, spanning standard and mini variants for different cost-performance trade-offs. Through RunAPI, all GPT models share the same API shape and billing.

Provider
OpenAI
See all →
Modality
Text
Browse models →

Why Use GPT Through RunAPI

One auth, every provider

A single RunAPI API key unlocks the whole model catalog across all providers. No separate accounts to create, no API keys to rotate per integration, and no credential management overhead. Add a new model to your app by changing one parameter.

Unified pricing & billing

Per-call pricing in USD, billed monthly into a single invoice. No subscription tiers, no minimum spend, and failed generations are never charged. The pricing page and check_pricing API show exact costs before you commit to a model.

Schema-first SDK

Typed schemas, parameter constraints, and setup notes are packaged in the model skill so your implementation starts from the right contract. The skill loads into Claude Code, Codex, Gemini CLI, Cursor, and VS Code — your agent knows the correct request shape before you write a line of code.

GPT Questions

Which GPT variant should I choose?

GPT-5.6 — the sol, terra, and luna tiers — is the current flagship generation. GPT-5.4 remains a strong choice for coding and agentic workflows, GPT-5.5 for long-horizon autonomous tasks, and GPT-5.4-mini is the cost-effective option for simpler tasks.

Does GPT support tool use and function calling?

Yes — all GPT-5 variants support structured function calling with JSON schemas, enabling agentic tool-use workflows.

What is Thinking mode?

Thinking mode lets GPT reason step-by-step before responding. Available on GPT-5.2 and above, it improves accuracy on complex reasoning tasks.

What is the context window size?

Context windows vary by variant. GPT-5.4 and above support large context windows suitable for multi-file code analysis and long documents.

Which variant should I start with?

Pick the cheapest variant that meets your quality bar. Most teams start on the fast variant and graduate to pro for production.

Is there a free tier?

Creating an account and API key is free. API calls use prepaid, pay-as-you-go billing; add funds before making requests.

SIMILAR MODELS

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