SIP PBX Trigger Extension Event

Overview

Use SIP PBX Trigger with Trigger On = Extension Event to:

• host extension registration inside n8n
• receive calls originating from registered extensions
• optionally let the workflow participate in auth decisions
• optionally let the workflow decide whether daemon-owned global recording should start

Main Parameters

Parameter	Required	Shown when	Description
Trigger On	Yes	Always	Select Extension Event.
Extensions Ref	Yes	Always	Stable public extensions group name.
Auth Mode	Yes	Always	Static, Digest First, or Raw.
Static Credentials	Yes for static auth	Auth Mode = Static	Collection of username/password/extension triples.
Global Call Recording	No	Always	Enables the Recording branch.

Static Credential Fields

Field	Required	Description
Username	Yes	SIP auth username matched against inbound auth.
Password	Yes	SIP auth password for static auth.
Extension	Yes	Extension number assigned to this credential entry.

Options

Option	Shown when	Description
Codecs	Always	Allowed SIP audio codecs for this extensions route. This is an allow-list only, not a priority override. The runtime keeps its built-in codec priority. Applies both to inbound extension-side traffic on this trigger and to outbound Dial -> Make Call in Mode = Extension when the dial resolves through this extensions route.
DTMF Methods	Always	Allowed inbound and outbound DTMF methods for this extensions route: RFC2833, SIP INFO, Inband. This is a filter only, not a priority override. Applies both to inbound extension-side traffic on this trigger and to outbound Dial -> Make Call in Mode = Extension when the dial resolves through this extensions route.
Auth Timeout (Seconds)	Auth Mode = Digest First or Raw	How long the trigger waits for Respond To Auth before assuming not_applicable.
Respond to recording timeout (Seconds)	Global Call Recording = on	How long the trigger waits for Respond to recording.
Transport	Always	Current UI exposes UDP.
Local Bind Port	Always	UDP port for inbound SIP listener.
TLS Bind Port	Always	Reserved UI field for TLS listener port.
Local Bind IP	Always	Explicit local bind address.
Advertised IP	Always	Public host or IP used in Contact/Via fallback identity.
Realm	Always	SIP auth realm exposed to remote side.
Username Prefix	Auth Mode != Raw	Trigger applies only when auth username starts with this prefix. The prefix is stripped only for static credential lookup.
Continue On Auth Reject	Always	If enabled, a reject from this trigger does not stop later matching auth candidates on the same endpoint.

Auth Modes

Auth Mode	Auth branch	Meaning
Static	No	Runtime authenticates directly against the configured static credentials.
Digest First	Yes	Runtime models digest auth but asks the workflow for the decision.
Raw	Yes	Workflow receives the auth request with minimal runtime assumptions and decides what to do.

Media Filter Notes

Topic	Behavior
Codec priority	The Codecs option only removes codecs from consideration. It does not reorder them.
DTMF method priority	The DTMF Methods option only enables or disables methods. It does not define a user-facing priority order.
Inband DTMF	If Inband is allowed, the runtime also runs audio-tone detection in addition to SIP/RTP DTMF paths.

Output Branches

Branch	When it appears	Meaning
Call	Always	Extension-originated inbound call.
Recording	Global Call Recording = on	Trigger-side recording decision request.
Auth	Auth Mode != Static	Workflow auth decision request for inbound REGISTER or INVITE.

Call Output Payload

Field	Meaning
eventType	Trigger event type, typically invite.
ref	Public extensions ref.
legId	Live leg created for the call.
callId	SIP call identifier.
direction	Runtime call direction string.
extension	Resolved extension number for this request.
from	Caller SIP URI.
callerNumber	Parsed caller number or SIP user.
callerName	Parsed caller display name.
to	Called SIP URI.
calledNumber	Parsed called number or SIP user.
calledName	Parsed called display name when present.
raw	Normalized SIP inspection object.
sipPbx.ref	Hidden routing metadata.
sipPbx.legId	Hidden leg resolution metadata.

Auth Output Payload

Field	Meaning
authRequestId	Request ID for Respond To Auth.
ref	Public extensions ref.
requestType	SIP method being authenticated, typically register or invite.
auth	Flat auth object such as username, realm, nonce, uri.
remoteIp	Remote source IP.
remotePort	Remote source port.
transport	SIP transport, currently udp.
localIp	Local listener IP used for this request.
localPort	Local listener port used for this request.
raw	Normalized SIP request inspection object.
sipPbx.authRequestId	Hidden request handle used by automatic respond resolution.

Recording Output Payload

Field	Meaning
eventType	Recording trigger event type.
recordRequestId	Request ID for Respond to recording.
kind	Recording request kind.
ref	Public extensions ref.
legId	Live leg to record.
callId	SIP call identifier.
direction	Runtime call direction string.
extension	Resolved extension number for this call.
from	Caller SIP URI.
callerNumber	Parsed caller number.
callerName	Parsed caller display name.
to	Called SIP URI.
calledNumber	Parsed called number.
calledName	Parsed called display name.
sipPbx.recordRequestId	Hidden request handle used by automatic respond resolution.

Follow-Up Action: Respond To Auth

Use SIP PBX -> Respond -> Respond To Auth.

Parameter	Required	Shown when	Description
Action	Yes	Always	Allow, Verify Digest Password, Not Applicable, Challenge, or Deny.
Password	Yes	Action = Verify Digest Password	Digest password to verify against the inbound auth request.
Extension	No	Action = Allow or Verify Digest Password	Optional explicit extension override. Leave empty when it can be derived from the auth username.
Status Code	Yes	Action = Challenge or Deny	SIP response status code.
Reason	Yes	Action = Deny	SIP reason phrase or workflow-defined reject reason.
Options -> Request ID	No	Always	Explicit auth request override. Usually resolved automatically from the trigger item.

Follow-Up Action: Respond to recording

For recording parameters and outputs, see SIP PBX Global Recording.

The Recording branch can also fire for outbound calls created through Dial -> Make Call when that dial resolves through this extensions route.