WebSocket Trigger
input.websocket Input v0.1.0 Accepts a persistent WebSocket connection; each inbound message starts the workflow, and data sent to its feedback input is pushed back to connected clients.
Finding it in the library
Search the builder's node library for WebSocket Trigger (it lives under Input). 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.
Library capture pending — regenerate with npm run shots:nodes.
Wired up in the builder
WebSocket Trigger 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.
Canvas capture pending — regenerate with npm run shots:nodes.
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.
Config capture pending — regenerate with npm run shots:nodes. See the full property reference below.
Ports
This is a trigger — it starts runs and takes no input wire.
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 | What flows through it |
|---|---|---|---|
| Output | output | Message |
How data flows through it
As a trigger, WebSocket Trigger starts runs — it takes no input wire. What it emits is
the request wrapper: the event’s body becomes the payload, and the wrapper
carries the event metadata around it (for an HTTP-style trigger that’s
headers.*, request.method, request.path and
query). Downstream nodes consume the content — the wrapper is unwrapped
at each node boundary, and expression roots like {{ headers.x }} still
resolve against the wrapper when you need the metadata. See
Runs & run data for the envelope model.
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 path, subprotocol, authUser, authPassword, authHeaderName, authHeaderValue, authToken, ipAllowlist. 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
(WebSocket Trigger) works as well as the exact type id (input.websocket).
In the Copilot panel (or any connected AI):
create a workflow that starts with websocket trigger and logs the result As a step in a create_chain_workflow call:
{"type":"WebSocket Trigger","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": "WebSocket Trigger" } } }' 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.
Input — what the node received
{
"msg": "hi"
} Output — what the node produced
{
"msg": "hi"
} Property reference
Every setting, with its type and default — the same fields shown configured in the panel above.
| Property | Type | Default | Description |
|---|---|---|---|
Pathpath | string | "/ws" | URL path the WebSocket server listens on. |
Subprotocolsubprotocol | string | — | Optional WebSocket subprotocol to negotiate. |
Heartbeat (seconds)heartbeatSeconds | int | 30 | Ping interval that keeps idle connections alive. |
Max connectionsmaxConnections | int | — | Optional cap on concurrent connections. |
Max message (bytes)maxPayloadBytes | int | 1048576 | Largest inbound WebSocket message this trigger accepts — an oversized message closes the socket (code 1009). 0 = unlimited (a 128 MB safety wall still applies). |
AuthenticationauthType | select | "none" | Require credentials on incoming requests: Basic (user/password), Header (exact header match), Bearer (Authorization: Bearer <token>). Checked before rate limits — rejected requests never reach the workflow. basicbearerheadernone |
CredentialcredentialId | credential | "" | Use a stored credential for this connection — its fields are filled in at run start. Pick "None" to enter the connection details manually. accepts credential templates: http-basichttp-headerhttp-bearerShown when String(authType ?? "none") !== "none" |
UserauthUser | string | — | Expected Basic-auth user name. Shown when String(authType ?? "none") === t |
PasswordauthPassword | string | — | Expected Basic-auth password. Shown when String(authType ?? "none") === t |
Header nameauthHeaderName | string | — | Name of the header that must carry the shared value, e.g. x-api-key (case-insensitive). Shown when String(authType ?? "none") === t |
Header valueauthHeaderValue | string | — | Exact value the header must carry. Shown when String(authType ?? "none") === t |
TokenauthToken | string | — | Expected bearer token — requests must send Authorization: Bearer <token>. Shown when String(authType ?? "none") === t |
IP allowlistipAllowlist | string | "" | Comma-separated client IPs or CIDR ranges allowed to call this trigger. Empty = allow all. Rejections are 403 before anything else runs. |
Rate limit (req/s)rateLimitRps | double | 0 | Per-client-IP sustained request rate for this trigger. 0 = no rate limit (the default). For internet-exposed apps, prefer rate limiting at a fronting reverse proxy (docs/ingress-guards-design.md). |
Rate limit burstrateLimitBurst | int | 0 | How many requests a client may send back-to-back before the per-second rate applies. 0 = automatic (2× the rate). Shown when (showIf === undefined || showIf(c)) && Number(rateLimitRps ?? 0) > 0 |
Related nodes
The rest of the Input 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.