Trigger Targets — WIL Trigger Node

A WIL Button or CHEFS Form trigger runs a single kind of target:

targetKind	What runs	Stored columns
n8n-node (only)	A published n8n workflow, started in-process at its WIL Trigger node	target_workflow_id, target_node_id

The outbound webhook-URL target that earlier drafts supported has been removed — a trigger can only invoke a WIL Trigger node. Breaking change: migration 0012 deletes every existing trigger that has a trigger_url (all legacy webhook triggers) and drops the trigger_url / trigger_method columns. Re-create those triggers against a WIL Trigger node after deploying. The database enforces the node-only shape with chk_wt_target_shape. See the node's documentation.

Flow

1. The editor picks a workflow from GET /ui-api/wil/trigger-targets?source=button|chefs-form.
2. POST/PUT /ui-api/wil/triggers validates the target (published, in a tenant project, node present and enabled, accepts the trigger type, button input values match the node's declared fields) and stores only (workflowId, nodeId).
3. POST /ui-api/wil/triggers/:id/callback checks the actor, re-resolves the target against n8n's published version, then starts the run with execution mode trigger. No webhook URL is involved and the request never leaves the n8n process.

Trust model

• Binding: any tenant manager (project:editor in the tenant, or the owner of a personal-project tenant) can bind a trigger to any published WIL Trigger workflow owned by one of the tenant's projects. WIL does not check the manager's own n8n access to that workflow, because tenant roles are tenant-wide, not per project.
• Exposure: whoever can publish a workflow containing a WIL Trigger node makes it available to every manager of the tenant. Accepted Sources on the node is the only per-workflow gate.
• Execution identity: the run uses the workflow owner's credentials. The firing user is passed in actor as data only; it is not signed and not an n8n identity, so workflows must not treat it as proof of identity beyond what WIL's own checks already enforced.
• Results: in lastNode mode the last node's output is returned to the caller, so workflow authors must not output data the allowed actors should not see.
• Tenant scope: the tenant comes from the X-TENANT-ID header, and CSTAR tenant-access verification is still a TODO (shared with the rest of the WIL routes).

Endpoints

GET /ui-api/wil/trigger-targets

Manager-only. Query: source (optional). Returns { data: Target[], enabled: boolean }; enabled is false (and data empty) when WIL_N8N_NODE_TRIGGERS_ENABLED=false. Each target carries workflowId, workflowName, nodeId, label, description, acceptedSources, inputSchema, respondMode, responseTimeoutSec.

POST/PUT /ui-api/wil/triggers

targetKind is always n8n-node; it may be omitted and defaults to n8n-node. The body below is for POST. PUT /ui-api/wil/triggers/:triggerId uses a strict schema that does not accept triggerType (the type cannot change after creation), and unknown keys such as the legacy triggerUrl are rejected.

{
  "triggerType": "button",
  "targetKind": "n8n-node",
  "targetWorkflowId": "abc123",
  "targetNodeId": "6f1c…",
  "metadata": { "buttonText": "Approve", "inputValues": { "amount": 100 } },
  "allowedActorsType": "all",
  "allowedActors": ["*"]
}

An unavailable target or invalid input values return 422 with details.reason / details.errors. Responses and list items include targetKind, targetWorkflowId, targetNodeId and targetStatus (live | unpublished | missing-node).

POST /ui-api/wil/triggers/:id/callback

Outcome	Status	Body
Started (respondMode: immediately, or lastNode timed out)	202	{ success, executionId }
Finished within the timeout (lastNode)	200	{ success, executionId, result }
Workflow unpublished / node removed / source no longer accepted	409	details.code = WIL_TARGET_UNAVAILABLE
Run failed	502	{ error: { message, executionId } }
Workflow failed to start	502	{ error: { message } } (no executionId)
Feature disabled, or n8n internals not found after an upgrade	503	–
Caller not allowed, or tenant has no linked projects	403	–
Unknown trigger id	404	–
Missing or invalid X-TENANT-ID	400	–

A lastNode run that is still waiting or running (for example at a Wait node) also returns 202, and result is omitted when the last node produced no output.

The item given to the node: { source: 'wil', trigger: { id, type, name }, actor: { email, tenantId, roles, groups }, input, firedAt }. For buttons input is metadata.inputValues; for CHEFS forms it is the submitted body.

Configuration

Variable	Default	Purpose
WIL_N8N_NODE_TRIGGERS_ENABLED (only the exact value false disables it; read at startup, so changing it needs an external-hooks restart)	true	Kill switch for the whole feature. When false, the dropdown is empty, saving a trigger fails with 400, and firing returns 503.
WIL_TRIGGER_NODE_TYPES	CUSTOM.wilTrigger,community-nodes.wilTrigger	Comma-separated node type strings used for discovery. n8n prefixes the node with its package name: CUSTOM when loaded from a custom extensions folder, community-nodes for the installed package.

Implementation notes

• N8nWorkflowRunnerService is the only module that touches n8n execution internals (WorkflowRunner, ActiveExecutions); it resolves them lazily and degrades to a 503 if they cannot be found after an n8n upgrade.
• Discovery reads n8n's published workflow history (honouring N8N_USE_WORKFLOW_PUBLICATION_SERVICE), so only published, non-archived workflows owned by the tenant's projects are listed.
• Runs are subject to n8n's usual execution handling (queue mode, credential checks); see .kiro/artifacts/wil-trigger-node/PHASE0-FINDINGS.md for the items that still need a live-instance check.