CPI IDoc Part 1: Sending IDocs from S/4HANA to Cloud Integration

📌 KEY POINTS
✅ S/4HANA sends IDocs to Cloud Integration over HTTP using an XML HTTP port (WE21).
✅ The port uses an HTTP RFC destination (type G in SM59) pointing to the iFlow's IDoc sender endpoint.
✅ Partner profiles (WE20) assign message types to the port for the partner.
✅ The iFlow uses the IDoc sender adapter, which receives IDoc XML.
⚠️ Authentication between S/4HANA and Cloud Integration must use a technical user or certificate, not a personal user.

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▶ WHERE WE ARE
This series covers IDoc integration. Part 1 covers outbound IDocs from S/4HANA.

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▶ 1. WHY IDOCS STILL MATTER
IDocs remain common for master data and transactional integration with S/4HANA: orders, deliveries, invoices, material and customer data. Many partners and third-party systems expect them. Cloud Integration handles IDocs natively with the IDoc adapter.

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▶ 2. RFC DESTINATION
In SM59, create an HTTP connection to an external server (type G) with the Cloud Integration runtime host and the path of the iFlow endpoint, for example /cxf/... configured in the IDoc sender adapter. Configure TLS and authentication, typically client certificate or OAuth-capable setups, or basic authentication with a technical user.

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▶ 3. PORT AND PARTNER PROFILE
In WE21, create an XML HTTP port that references the RFC destination. In WE20, add the outbound message types for the partner (often a logical system representing the target) with this port. Output determination or distribution models then create IDocs for that partner.

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▶ 4. THE IFLOW
The IDoc sender adapter receives the IDoc XML; the iFlow maps and routes it to the receiver. A Cloud Integration role must be assigned to the technical user so S/4HANA is allowed to call the endpoint.

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▶ 5. CHECKING STATUS
In WE02 or WE05, outbound IDocs show status 03 when successfully passed to the port. Errors such as 02 or 29 indicate port or communication problems; SM59 connection tests help. The message processing log in Cloud Integration shows what happened afterwards.

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▶ STEP BY STEP

1. Create an iFlow with an IDoc sender adapter and deploy it.
2. Create an SM59 type G destination to its endpoint.
3. Create an XML HTTP port and partner profile.
4. Send a test IDoc and check WE02 and the message log.

✅ CHECKPOINT: a test IDoc reaches the iFlow with status 03 in S/4HANA and success in Cloud Integration.

Outbound IDocs stayed in status 02 after go-live. The SM59 destination worked in the connection test but used a personal user whose password had expired. Switching to a technical user with certificate authentication and monitoring the destination prevented recurrences.

• Personal users in RFC destinations.
• Wrong endpoint path in SM59.
• Missing Cloud Integration role for the technical user.
• Not checking both WE02 and the message log.

• Technical users or certificates.
• Endpoint naming conventions.
• Status monitoring on both sides.
• Document partner profiles.

Interviewers ask how to configure S/4HANA to send IDocs to Cloud Integration (SM59, WE21, WE20) and how to check where an outbound IDoc failed.