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- Chat Completion
ActionOpenAIUpdated May 2026
How do I call an OpenAI chat model from a workflow?
Short answer: Drop the "OpenAI → Chat Completion" action anywhere in your workflow, map the inputs from upstream nodes, and publish.
Inputs
The fields this action accepts.
Every field can be mapped from an upstream trigger, AI step, table row, or hard-coded literal.
| Field | Type | Required | Description |
|---|---|---|---|
Model model | options | Required | Which OpenAI model to use |
Message message | string | Required | The user message to send |
System Prompt system_prompt | string | Optional | Instructions that shape how the model responds |
Temperature temperature | string | Optional | Controls randomness (0 = deterministic, 2 = very creative). Default is 1. |
Max Tokens max_tokens | string | Optional | Maximum number of tokens in the response |
Sample request
{"model": "{{trigger.model}}","message": "e.g. Summarize this document...","system_prompt": "e.g. You are a helpful assistant.","temperature": "e.g. 0.7","max_tokens": "e.g. 1024"}
Returns
{"id": "chatcmpl-abc123","model": "gpt-4o","usage": {"total_tokens": 30,"prompt_tokens": 10,"completion_tokens": 20},"object": "chat.completion","choices": [{"index": 0,"message": {"role": "assistant","content": "Hello! How can I help you?"},"finish_reason": "stop"}]}
Use these fields in downstream nodes for routing, logging, or error handling.
Triggered by
Apps that pair well as the trigger for Chat Completion.
Any of these apps can fire this action as part of a workflow.
FAQ
Questions about Chat Completion.
What does the Chat Completion action do in OpenAI?
Sends a message and gets a response from an OpenAI chat model (gpt-4o, gpt-4o-mini, o-series, etc.). The standard chat-completion action; supports system prompts, temperature, and stop sequences.
What inputs does Chat Completion require?
Required: Model, Message. Every input accepts a static value or a variable from any upstream node in your workflow.
Can I use dynamic inputs from earlier workflow nodes?
Yes. Any field on this action can pull values from upstream nodes, whether that's a form response, a trigger payload, an AI output, or a lookup result.
What happens if OpenAI returns an error?
The workflow pauses on the failed node, the error message is captured in the run log, and you can retry the run with one click. Auto-retry policies are configurable per workflow with exponential backoff up to 5 attempts.
Does Chat Completion support batch operations?
Yes. Run Chat Completion inside a Loop node to process arrays. Tiny Command handles OpenAI's rate limits automatically so you don't have to throttle manually.
More actions
Other OpenAI actions.
Action
Analyze Image
Analyzes an image using GPT-4o vision, accepting a URL or base64-encoded image plus a text prompt. Use for OCR, chart extraction, alt-text generation, or visual QA.
ActionChat with Tools
Chat completion with tool/function calling enabled. The model may return tool_calls instead of (or in addition to) text; you execute them and feed results back as tool messages for the next turn.
ActionCreate Batch
Submits a batch of OpenAI requests at a 50% cost discount with a 24-hour SLA. Requires an uploaded JSONL file id with one request per line. Perfect for bulk classification or embedding jobs.
ActionCreate Embedding
Generates vector embeddings for text using text-embedding-3-small or text-embedding-3-large. The de-facto embeddings default for RAG and semantic search.
ActionCreate Image (DALL-E)
Generates images from a text prompt using DALL-E (or gpt-image-1). Supports size, quality, and style controls; returns a URL or base64-encoded image.
ActionCreate Response
Creates a model response using OpenAI's Responses API, the unified endpoint that supersedes chat-completions for new use cases. Supports tools, vision, structured output, and file inputs in a single call.
Send chat completion from your workflows.
Triggered by anything in the catalog. Free tier available. No credit card.