OpenAI Responses API Adapter for n8n LLM & AI Agents

This workflow serves as a bridge for OpenAI's Responses API, allowing impatient users to integrate it into n8n's LLM and AI Agent workflows before official support arrives. It uses n8n's built-in webhooks to create a custom API wrapper: incoming requests from agent nodes are intercepted, remapped to match the Responses API format via an HTTP node, and responses are transformed back for Langchain compatibility—supporting both streaming and non-streaming modes.

Key benefits include immediate access to advanced OpenAI features like improved reasoning and tool-calling in agentic workflows, without overhauling existing setups. It saves significant development time by handling protocol mismatches automatically, enabling faster iteration on AI applications.

Ideal use cases: Enhancing production AI agents with Responses API capabilities, experimenting with other LLMs via the same pattern, or prototyping complex multi-step reasoning tasks. Requires an OpenAI account; activate the workflow, set up a custom credential pointing to its webhooks, and swap into your LLM nodes.