All nodes/AI/LLM

Structured Output LLM

Calls an LLM and returns the response strictly in JSON format according to a given schema (structured output). Used when you need typed output rather than free text. Requires an LLM via link_llm.

Structured Output LLM▶

LLMOutput

Message

System

Type in the graph: structured_output_llm

Exec

An error branch can be enabled (expose_error_output) to handle failures on their own path.

Ports can be split into separate execution and data handles.

Try it

Minimal working workflow

Entry

Structured Output LLM▶

LLM▦

Exit▶

Execute + Data
LLM

Press “Copy nodes”, open the editor and hit Ctrl+V on the canvas.

Runs as pasted

When to use it

Reach for this node when the model’s answer has to travel on as data rather than as text: splitting an email into fields, classifying a request, pulling out an amount and a date, producing a list of tags. The model must answer with an object matching your JSON Schema, so the next node receives a ready object instead of a string to parse. For free text in a chat use LLM Response; for a model that acts on its own use the AI Agent.

How it works

The schema goes in the “Structured output schema” field. Its fields are available downstream as {{ nodes.<id>.output.<field> }}, and the whole object travels along the edge. The default schema has a single string field result, so a freshly dropped node runs immediately; replace it with your own shape.

The top-level schema must be an object. An array or a scalar is wrapped automatically into an object with one value field, and the result then has to be read as {{ nodes.<id>.output.value }}.

Field descriptions are read by the model as instructions. One precise field description often does more than a paragraph in the system prompt.

The node does not stream: the answer arrives whole, once the model has finished it.

Common mistakes

The System port is wired but the prompt did not change. “System prompt source” defaults to “Template”, and a connected port is not read in that mode. Switch it to the connected System port, or to Auto.
Sending the object straight to Exit. The chat then shows JSON. If a human needs to read it, assemble the text with a Template node — or add a text field to the schema and let Exit show that.
An exotic schema. Not every model accepts pattern, format, oneOf/anyOf/allOf or deeply nested $ref. If the node fails saying no structured-output method worked, simplify the schema or change the model.
An empty result. The model returned a refusal instead of an object: check that the schema is an object at the top level and that the prompt really asks for those fields.

Inputs

Port	Wire	Payload	Notes
LLM`llm`	LLM`link_llm`	—	LLM config from llm node (registry or workspace connection)
Message`message`	Execute + Data`execute_data`	`message`	User message sent to the LLM
System`system`	Data`data`	—	System prompt override

Outputs

Port	Wire	Payload	Notes
Output`output`	Execute + Data`execute_data`	`object`

Configuration

Field	Type	Default	Description
Message Source`message_source`	`string`	`auto`	auto -- use connected input if available, else template; connected -- always from edge; template -- always from template Options: `auto` — Auto (connected input, else template), `connected` — Connected input, `template` — Template
User Message Template`user_prompt_template`	`string`	`""`	Used when source=template or no edge connected. Supports {{inputs.message}}, {{nodes.xxx.output.yyy}} supports templates
System Prompt Source`system_source`	`string`	`template`	auto -- use connected system input if available, else template Options: `auto` — Auto (connected System port, else template), `connected` — Connected System port, `template` — Template
System Prompt`system_prompt`	`string`	`""`	System prompt template supports templates
Structured Output Schema`structured_output`	`object`	`{"type":"object","properties":{"result":{"type":"string","description":"The m…`	JSON Schema object the model must answer with; the top-level title is optional (it becomes the API tool name). Defaults to a single string 'result' field so a freshly dropped node runs — replace it with your shape.
Advanced
Use Chat History`use_chat_history`	`boolean`	`false`	Pass full chat history to LLM instead of only last message

Shared fields

Every node has these three — the platform adds them, not the node author.

expose_error_output — When enabled, show an execution output to connect nodes that run if this step fails.
split_ports_in — Show separate execution and data input handles instead of one combined port.
split_ports_out — Show separate execution and data output handles instead of one combined port.

Ready-made examples using this node

Structured data extraction