The node categories available in the Flow Studio canvas, and the safety limits every flow runs under.

Building Blocks

A flow graph uses nodes connected by edges. Every graph starts at one Start node and runs edge by edge until each branch reaches an End, dead end, or Abort. The palette shows only nodes valid for the current phase.

Control

Node	Purpose
Start	The phase entry point. Placed automatically; exactly one per non-empty phase.
End	Hands the request back to the gateway to continue to the next stage.
Abort	Blocks the request with a status code and message. Not available post-response because the reply already left.

Logic

Node	Purpose
If	Branches on one or more conditions (`equals`, `not equals`, `greater/less than`, `contains`, `exists`, `matches`, `in`), combined with AND/OR. Exposes `true`/`false` outputs.
Switch	Multi-way branch on one value, with a case per expected value and a `default` output.
Loop	Iterates over a list (for example, each message in a conversation), running its body once per item. Exposes `body` and `done` outputs.
Parallel	Runs branches concurrently and joins them before continuing. This is separate from Execution Lanes.
Wait	Pauses the graph for a bounded delay.

Data

Node	Purpose
Set Variables	Assigns one or more flow variables for later nodes to read.
Template	Renders a text template (mixing static text and expressions) into a variable.
Transform	Sets, copies, or deletes fields on the request, response, or flow variables in one step.

Request (Pre-route, Pre-upstream)

Node	Purpose
Get Request Value	Reads a field from the request into a variable.
Set Request Value	Writes into the request body, model, or metadata.
Set Request Headers	Adds or removes headers sent upstream.
Route Model	Rewrites the target model for tiered or conditional routing.

Response (Post-upstream; reading is also available at Post-response)

Node	Purpose
Get Response Value	Reads a field from the upstream response into a variable.
Set Response Value	Writes into the response body, status, or metadata before the caller sees it.
Set Response Headers	Adds or removes headers on the reply.

Integrations

Node	Purpose
HTTP Request	Calls an external endpoint and exposes status, body, headers, and success flag. Failures can follow a separate `error` output.
Send Webhook	Sends fire-and-forget JSON to a URL. It never blocks the request, even on failure.

Context, Plugins & Utility

Node	Purpose
Organisation Lookup	Loads details about the requesting organisation for use later in the graph.
Run Plugin	Invokes an already activated marketplace or built-in plugin with its normal configuration. If it aborts, the flow and request abort.
Log	Writes a structured gateway log line for build and debug work.
Note	A text annotation on the canvas — has no runtime effect.

Expressions

Fields can reference live request, response, and flow state with {{double-brace}} expressions. A field that is exactly one expression keeps the native type. An expression mixed into text renders as a string.

Reference	Resolves to
`{{request.body...}}`	The parsed request body, e.g. `request.body.messages.0.content`
`{{request.model}}`, `{{request.path}}`, `{{request.method}}`	Routing fields for the current request
`{{request.headers.x-team}}`	A request header
`{{request.organisation_id}}`, `{{request.api_key_id}}`, `{{request.metadata...}}`	Caller and context identifiers
`{{response.body...}}`, `{{response.status}}`, `{{response.headers...}}`	Available in post-upstream and post-response phases only
`{{vars.name}}`	A flow variable set earlier in the same run
`{{nodes.<id>.<field>}}`	An earlier node's output, e.g. `nodes.lookup.body.team`
`{{item}}`, `{{index}}`	The current element and position inside a Loop body
`{{phase}}`, `{{now}}`	The current phase name and current timestamp

Building Limits

Flows run in the live request path. Every graph uses these limits:

Limit	Bound
Nodes per phase	150
Edges per phase	400
Node executions per run	2,000
Walk depth	64
Loop iterations	500
Parallel branches	8
Wait duration	2 seconds in request-blocking phases, 10 seconds in post-response
HTTP Request timeout	30 seconds, 1 MiB response, 5 redirects
HTTP Request destinations	Private and loopback addresses are refused by default, closing off internal network access from a flow's outbound calls

A flow that fails validation or hits an unexpected load-time error is skipped for that request. The gateway fails open on broken flows. See Testing & Verification.

Node Errors vs. Aborts

A node error, such as an HTTP Request timeout without an error output, does not stop the request by default. The failing branch stops and the rest of the graph continues. You can switch a flow to treat node errors as hard stops, matching Abort behavior. Use strict mode for load-bearing steps, such as required enrichment. Keep the default for best-effort steps, such as optional notifications.

Building Blocks

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