What is AS2

AS2 (Applicability Statement 2) is a widely used protocol for securely exchanging data over the internet, especially in supply chains. It enables businesses to send EDI documents and other files directly between systems with encryption, digital signatures, and acknowledgments for delivery confirmation. AS2 is a preferred standard for many retailers, manufacturers, and logistics providers because it ensures both security and compliance. With Chain.io’s built-in AS2 server, you can connect to trading partners without relying on third-party gateways or extra infrastructure—keeping your data in sync and your operations moving.

Getting Started

To enable AS2 for your workspace, the first step is to create your AS2 profile.  You can have multiple, but in most cases you’ll only need one.

1. Go to Workspace Settings → AS2 Profiles.
2. Select Add AS2 Profile if you don’t have one. Enter your Trading Partner ID, then select Create.
3. Download or copy your public certificate to share with your partner when they need to send data to you.

Chain.io manages all of the background settings as well as your private certificates, so you don’t need to worry about any of that.

Sending Data To Someone Else’s AS2 Server

When sending data to someone else using a Chain.io Send flow, you need to create a connection within the integration that represents the trading partner you’re communicating with.  Then you’ll use that connection in one or more flows to send data to the trading partner.

1. Open the target Integration → Connections.
2. Select New → choose AS2 under the Send Data From Host System section
3. Complete the fields on the new AS2 form. Descriptions are below.
4. Save the connection
5. Use the connection on any send flow.

AS2 Configuration Fields

• Name - Clear, descriptive name.
• AS2 Profile - Select the profile you just created.
• Partner AS2 ID - Your partner’s AS2 identifier.
• Partner URL - Your partner’s AS2 HTTP(S) endpoint.
• Partner Certificate - Upload the partner’s public certificate.
• Partner Certificate Chain - Upload the chain if provided by the partner.  (If they provide the chain in multiple components, you’ll need to paste them in with the intermediate at the top and the root below it)
• Message Subject - Subject header for the transmission.
• Compression - Enable ZLIB if agreed.
• Encryption Algorithm - Choose AES or None. Use None only if the URL is HTTPS.
• Signing Algorithm - Select the SHA option your partner supports.
• MDN Algorithm - Pick the MDN signing algorithm or None.
• MDN Response - Usually SYNC unless your partner requests otherwise.

Receiving Data Into Your Chain.io AS2 Server

When your partner is going to send data to you using a Receive Flow, 

1. Open the target Integration → Connections.
2. Select New → choose AS2 under the Receive Data Into Host System section
3. Complete the fields on the new AS2 form. Descriptions are below.
4. Save the connection
5. Use the connection on any receive flow.

AS2 Configuration Fields

• Name - Clear, descriptive name.
• AS2 Profile - Select the profile you just created.
• Partner AS2 ID - Your partner’s AS2 identifier.
• Partner Certificate - Upload the partner’s public certificate.
• Partner Certificate Chain - Upload the chain if provided by the partner.  (If they provide the chain in multiple components, you’ll need to paste them in with the intermediate at the top and the root below it)

Important Note On Routing

• When your partner sends data, they should send to as2.chain.io. We route data to your flows based on the Partner AS2 ID, so if you need multiple feeds to different flows have your partner use different IDs for each connection and setup separate Chain.io connections.
• When you are sending to partners, if they restrict on IP addresses, they should whitelist 23.23.130.9, 44.196.109.11, 3.219.16.7

AS2 Host Systems

• All AS2 functionality is also available as host systems.  Use host systems when you are connecting to internal systems which you need to use across multiple integrations.  The instructions are the same as connections, but utilize the Host Systems screen in your workspace settings.