AS4

Signed, encrypted B2B message exchange over AS4 with signed receipts

AS4 specificationAPI checked August 18, 2026

Signs in with: Connection details
Runs on: Cloud or On-Prem Worker
Operations: 1
Ready-made triggers: 0

Connect AS4

In Neblex open Connect › Connections and click New Connection.
Search for AS4 and give the connection a clear name.
Fill in the fields. Secret values are encrypted and never shown again.
Click Test, then Create Connection.

If the system is only reachable inside your network, choose an On-Prem Worker under Test from and run the flow on that Worker. See On-Prem Workers.

Field	What to enter
Partner URLRequired	HTTP(S) MSH endpoint without URL credentials or fragment; host must pass the runtime egress allow-list.Example: `https://as4.partner.example/msh`
Our party idRequired	ebMS From/PartyId.
Partner party idRequired	ebMS To/PartyId.
Our party ID typeOptional
Partner party ID typeOptional
ServiceRequired	Example: `urn:example:invoicing`
Service typeOptional
ActionRequired
Our roleOptional	Defaults to the ebMS initiator role URI.
Partner roleOptional	Defaults to the ebMS responder role URI.
Agreement ref (optional)Optional	Bilateral processing-mode agreement identifier.
Our signing certificate (PEM)Required	ECDSA P-256 certificate carried in the signed message.
Our signing key (PKCS#8 PEM)RequiredSecret
Partner certificate (PEM, for encryption)Optional	RSA certificate with a key of at least 2048 bits; required when Encrypt messages is on.
Encrypt messagesOptional
Our decryption key (RSA PKCS#8 PEM, inbound)OptionalSecret	Retained for inbound receive-gateway compatibility; unused by outbound send.
Partner signing certificate (PEM, inbound)Required	Pinned ECDSA certificate used to verify the synchronous signed receipt; embedded certificates are not trusted.
HTTP Basic usernameOptional	Optional transport authentication; must be configured with HTTP Basic password.
HTTP Basic passwordOptionalSecret	Optional transport authentication; must be configured with HTTP Basic username.
mTLS client certificate (PEM)Optional	Optional mTLS certificate; must be configured with its private key.
mTLS client private key (PEM)OptionalSecret	Optional mTLS private key; must be configured with its certificate.
Private CA certificate (PEM)Optional	Optional private trust anchor for the partner HTTPS endpoint.

Use it in a flow

Open a flow, open the node library and search for AS4.
Drag it onto the canvas and choose an Operation and your connection.
Map the operation's fields from earlier steps, or click Map with Matt.
Use Test this step to see what it returns, then save.

To start a flow from AS4 without a ready-made trigger: a Poll for changes trigger can check one of its list operations on a schedule and pass on only what is new; if AS4 can send webhooks, a Webhook trigger receives them at its own URL.

Operations

1 operations in 1 groups. Each one is a step you can add to a flow.

Message1

Send a documentsend Send one signed AS4/ebMS 3.0 UserMessage by HTTP Push and require a synchronous signed non-repudiation receipt; optionally gzip and encrypt the payload.