Validate JSON Schema

processing.validate-json-schema Processing v0.1.0

Validates input with an inline or context-provided JSON Schema.

The Validate JSON Schema step on the Studio canvas — The **Validate JSON Schema** step as it appears on the Studio canvas — input pins on the left, output ports on the right.

Finding it in the library

Search the builder's node library for Validate JSON Schema (it lives under Processing). A single click opens the in-editor docs panel shown here — description, ports, and every property, without leaving the canvas. Double-click (or drag) to add it to the workflow.

Validate JSON Schema in the node library, with the in-editor docs panel open — The library entry and the in-editor docs panel for **Validate JSON Schema** — the same reference this page is generated from.

Wired up in the builder

Validate JSON Schema in a real, runnable flow — captured live from the Studio editor, exactly as it looks on your canvas. This is the same workflow used for the example input & output below.

Validate JSON Schema wired into a runnable workflow in the Studio builder — **Validate JSON Schema** wired into a runnable flow — input on the left, output on the right.

How it’s configured

The node’s Configure panel as it opens in the builder when you select the step — every setting laid out with real values. Click any field to edit it.

The Validate JSON Schema node's Configure panel in the Studio builder — The **Configure** panel for **Validate JSON Schema**, showing the settings from the flow above.

Ports

Ports are the node’s contract with its neighbours. In the editor a port label renders bold when wired and italic when optional; ◈ ports accept attachment carriers rather than data wires.

Direction	Port	Label
Input	`input`	Input
Output	`valid`	Valid
Output	`invalid`	Invalid

How data flows through it

Validate JSON Schema consumes the content of the incoming envelope — when it is fed directly by a trigger, the trigger’s wrapper is unwrapped at the node boundary so the node sees the actual data, not the metadata shell. Its output becomes the payload for the next node, while the envelope (trace ids, correlation, binary refs) rides along untouched. In the Runs view you always see the whole envelope for both sides of this node.

Expressions in the config

String-typed properties accept {{ }} expressions evaluated against the incoming item at run time — e.g. {{ $json.customer.email }}. On this node that’s schemaRef. JSON- and code-typed fields never interpolate — they are passed through literally.

Build it with AI

Every node in this reference is reachable through Flowdrome’s AI Copilot and the MCP tools — say what you want, and the graph surgery happens server-side. Node types resolve fuzzily, so the catalog label (Validate JSON Schema) works as well as the exact type id (processing.validate-json-schema).

In the Copilot panel (or any connected AI):

add a validate json schema node after the trigger

As a step in a create_chain_workflow call:

{"type":"Validate JSON Schema","config":{}}

Raw MCP call — add this node to a workflow with add_node

curl -s -X POST http://localhost:48170/mcp -H "content-type: application/json" -d '{ "jsonrpc": "2.0", "id": "1", "method": "tools/call", "params": { "name": "add_node", "arguments": { "workflowId": "<id>", "type": "Validate JSON Schema" } } }'

Example input & output

Captured from a real test run of the workflow above — this is what you see in the run data panel after pressing Test workflow.

On this run the node emitted on ports valid, output.

Input — what the node received

{
  "kind": "json",
  "contentType": "application/json",
  "payload": {
    "a": 1
  },
  "body": {
    "a": 1
  }
}

Output — what the node produced

{
  "kind": "json",
  "contentType": "application/json",
  "payload": {
    "a": 1
  },
  "body": {
    "a": 1
  }
}

Property reference

Every setting, with its type and default — the same fields shown configured in the panel above.

Property	Type	Default	Description
Schema `schema`	`json`	`—`	Inline JSON Schema to validate the input against.
Schema reference `schemaRef`	`string`	`"workflow.input"`	Named schema to validate against when no inline schema is given.
Route invalid `routeInvalid`	`boolean`	`true`	Emit an invalid port instead of failing on schema errors.

Related nodes

The rest of the Processing group — the same folder you’d scan in the editor’s library.

This page is generated from the node registry by gen-node-docs.mjs on every site build — ports, properties, defaults and visibility rules cannot drift from the code. The screenshots and example data are captured from a live Flowdrome by npm run shots:nodes and npm run gen:examples.