OpenAI API

OpenAI is the leading **AI research and deployment company** that created ChatGPT, GPT-5, DALL-E, and Sora. The company provides powerful AI models through its API platform, enabling developers and businesses to integrate advanced language, vision, and reasoning capabilities into their applications.

API Platform Overview

OpenAI's API Platform gives developers programmatic access to state-of-the-art AI models for text generation, code completion, image analysis, vision tasks, audio processing, and video generation. Over 2 million developers and thousands of enterprises use OpenAI's APIs to power AI features in their products.

Flagship AI Models

GPT-5.2 ($1.75/1M input tokens, $14/1M output tokens): The most advanced language model, excelling at coding, agentic tasks, and complex problem-solving across industries. Supports up to 128K context window.

GPT-5.2 Pro ($21/1M input tokens, $168/1M output tokens): The smartest and most precise model for critical applications requiring maximum accuracy and reasoning depth.

GPT-5 mini ($0.25/1M input tokens, $2/1M output tokens): Faster, more affordable version of GPT-5 optimized for well-defined tasks. Ideal for high-volume applications where speed and cost matter.

GPT-4.1 series: Previous generation models still widely used for production applications, with nano, mini, and standard variants offering different price-performance trade-offs.

o4-mini reasoning model: Specialized model designed for complex, multi-step problems and STEM use cases requiring deep reasoning.

Advanced Capabilities

Multimodal Processing: Models can understand and generate text, images, audio, and video. GPT-image-1 generates high-fidelity images, while Sora-2 creates dynamic video content.

Code Generation: GPT-5.1-Codex-Max excels at software development tasks, from writing complete applications to debugging and code review.

Function Calling: Models can reliably call external functions and APIs, enabling agentic behaviors and tool use.

Structured Outputs: Generate responses in strict JSON schemas for reliable integration with applications.

Fine-tuning: Customize models on your data for specialized tasks. Training costs range from $1.50/1M tokens (GPT-4.1 nano) to $100/hour (o4-mini reinforcement learning).

Prompt Caching: Save up to 90% on costs by caching frequently used prompts.

Developer APIs

Chat Completions API: Build conversational interfaces with multi-turn dialogues, system instructions, and conversation history.

Responses API: Newest API combining Chat Completions simplicity with built-in tool use.

Assistants API: Create assistant experiences with persistent threads, file handling, and built-in tools.

Realtime API: Low-latency, multimodal experiences including speech-to-speech ($4-16/1M tokens for text).

Image Generation API: Create and edit images with GPT-image-1 (~$0.01-0.17 per image depending on quality).

Sora Video API: Generate richly detailed videos ($0.10-0.50 per 5-second clip depending on resolution).

Batch API: Save 50% on costs by processing large volumes asynchronously over 24 hours.

Built-in Tools

Code Interpreter ($0.03/session): Execute Python code in sandboxed environments for data analysis, calculations, and file processing.

File Search ($0.10/GB/day, $2.50/1K calls): Vector search across uploaded documents with automatic chunking and retrieval.

Web Search ($10/1K calls + token costs): Real-time internet access for models to retrieve current information.

AgentKit Platform

OpenAI's newest platform for building production-grade AI agents includes:

• Agent Builder: Design and iterate on agents with zero cost until deployment
• ChatKit: Pre-built conversational interfaces you can customize and deploy
• Evals: Testing framework to measure agent performance
• Storage: 1GB free, then $0.10/GB-day for file/image uploads
• Enterprise controls: SSO, RBAC, and audit logs included at no extra cost

Enterprise Features

Priority Processing: Guaranteed high-speed performance with pay-as-you-go flexibility.

Scale Tier: Dedicated capacity for high-volume applications.

Reserved Capacity: Lock in pricing and throughput for predictable workloads.

Security & Compliance: SOC 2 Type 2, GDPR, HIPAA (for healthcare), zero data retention options.

Enterprise Support: Dedicated account teams, SLAs, and priority assistance.

Use Cases

• Customer Support: AI chatbots and assistants handling millions of conversations
• Content Creation: Automated writing, translation, and copywriting at scale
• Code Development: AI pair programming, code review, and debugging
• Data Analysis: Extract insights from documents, spreadsheets, and databases
• Education: Personalized tutoring and learning experiences
• Research: Scientific paper analysis, hypothesis generation, literature review
• Creative Work: Image generation, video creation, marketing materials
• Automation: Agentic workflows that execute multi-step tasks autonomously

Developer Experience

SDKs & Libraries: Official Python and Node.js libraries, plus community SDKs for 20+ languages.

Playground: Interactive testing environment to experiment with models and settings.

Documentation: Comprehensive guides, API references, and cookbooks with code examples.

Community Forum: Active developer community for support and knowledge sharing.

Usage Dashboard: Real-time monitoring of API usage, costs, and rate limits.

API Keys: Fine-grained access control with multiple keys for different environments.

Pricing Model

Pay-as-you-go based on tokens processed. No monthly minimums or commitments required. Costs vary by model:

• Entry models: $0.20-0.80/1M tokens
• Standard models: $0.25-14/1M tokens
• Pro models: $21-168/1M tokens
• Batch API: 50% discount for async processing
• Fine-tuning: $1.50-100 depending on model and method

Prompt caching can reduce costs by 50-90% for repeated context.

ChatGPT Products

While the API is for developers, OpenAI also offers ChatGPT as direct-to-consumer and business products:

• ChatGPT Free: Access to GPT-4.1 with usage limits
• ChatGPT Plus ($20/month): GPT-5 access, faster responses, priority access to new features
• ChatGPT Business: Team collaboration, admin console, no training on your data
• ChatGPT Enterprise: Unlimited usage, data controls, SSO, analytics
• ChatGPT Edu: Education-specific features and pricing

OpenAI vs Competitors

vs Anthropic Claude: OpenAI offers more model varieties and tools, while Claude emphasizes safety and longer context windows (200K tokens).

vs Google Gemini: OpenAI has stronger developer ecosystem and enterprise adoption, while Gemini integrates with Google Cloud and Workspace.

vs Open Source (Llama, Mistral): OpenAI models generally outperform on benchmarks but require API calls vs self-hosting open models.

Key Advantages

• ✓ Most advanced models (GPT-5, o4) leading industry benchmarks
• ✓ Comprehensive platform with text, image, audio, video capabilities
• ✓ Mature developer tools and extensive documentation
• ✓ Enterprise-ready with security, compliance, and support
• ✓ Active ecosystem with 2M+ developers and growing
• ✓ Flexible pricing with pay-as-you-go and enterprise options
• ✓ Continuous innovation with regular model updates

Considerations

• ✗ Higher costs than open-source alternatives for high-volume use
• ✗ API dependency means downtime affects your application
• ✗ Rate limits on free and lower tiers can restrict usage
• ✗ Data privacy concerns for sensitive information (though enterprise options exist)
• ✗ Vendor lock-in if you build heavily on OpenAI-specific features

Who Uses OpenAI

OpenAI's platform powers AI features for companies like Microsoft (GitHub Copilot), Stripe, Shopify, Salesforce, Khan Academy, Duolingo, and thousands of startups. Over 92% of Fortune 500 companies use OpenAI's APIs.