OpenAI API

CrewAI connects to OpenAI's API via its LangChain model connector for agent reasoning and tool calling.

→ GPT-4o-powered CrewAI crews with native function calling and parallel agent task execution.

AutoGen calls OpenAI's API natively for agent reasoning, with full function calling and parallel agent support.

→ GPT-4o-powered multi-agent conversations with structured tool use and concurrent agent execution.

LangChain uses OpenAI's API via its ChatOpenAI class with native function calling and structured output support.

→ GPT-4o in any LangChain chain or agent with full tool calling and parallel function execution out of the box.

LlamaIndex uses OpenAI's API for both embedding generation and completions via its native adapters.

→ Best-in-class embeddings and generation in LlamaIndex pipelines — ada-002 or text-embedding-3 for retrieval, GPT-4o for generation.

Mastra connects to OpenAI's API natively for agent reasoning, tool calling, and structured output generation.

→ GPT-4o-powered Mastra agents with native function calling and real-time streaming support.

PydanticAI wraps OpenAI's API with a typed model interface, enforcing structured outputs through Pydantic models.

→ Type-safe GPT-4o responses in agent pipelines — structured data comes out of the model, not raw text.

SmolAgents uses OpenAI's API for its code generation and reasoning steps via a direct model connector.

→ GPT-4o-powered SmolAgents with strong code generation for the agent's tool-calling and multi-step reasoning.

Agno connects to OpenAI's API natively for agent reasoning, multimodal inputs, and structured tool calling.

→ GPT-4o-powered Agno agents with vision, audio, and structured function calling out of the box.

LiteLLM routes to OpenAI's API natively, treating it as the default provider in its unified format.

→ OpenAI access through LiteLLM's multi-provider interface — add fallbacks, cost controls, and model swapping without touching app code.

Portkey proxies OpenAI's API — change one base URL and every OpenAI call gets caching, retries, and load balancing.

→ Production-hardened OpenAI calls with automatic retry, prompt caching, and cost savings through Portkey's proxy layer.

Langfuse's SDK wraps OpenAI's client, capturing every API call with token counts, cost, and latency automatically.

→ Per-call observability on OpenAI usage — see exactly which prompts are expensive, slow, or producing poor outputs.

Helicone is a drop-in proxy for OpenAI's API — change one base URL and every OpenAI call is logged, cached, and monitored.

→ Immediate cost and request logging for OpenAI usage with zero code changes — one URL swap covers the entire app.

The Vercel AI SDK wraps OpenAI's API in its unified provider interface, handling streaming, tool calling, and structured output natively.

→ Streaming AI UIs backed by OpenAI with one import — useChat, useCompletion, and tool calling work out of the box.

Promptfoo calls OpenAI's API directly to run prompts through configured test cases and compare outputs against assertions.

→ Automated prompt regression testing against GPT-4o — catch output quality changes before they reach production.

DeepEval uses OpenAI's API as the judge model to score generated outputs on metrics like faithfulness, relevance, and hallucination rate.

→ LLM-as-judge quality metrics powered by GPT-4o — structured, reproducible evaluation scores for any AI output.

Letta agents use OpenAI models as their reasoning core, extended with Letta's persistent memory layer.

→ Long-running stateful agents that remember context across sessions without context window limits.

Azure OpenAI hosts OpenAI's models in Microsoft's data centers, accessible via the same OpenAI SDK.

→ OpenAI model access with enterprise compliance, data residency, and Azure AD integration.