cf-event-mesh

name	cf-event-mesh
description	Use when a task involves listening to or publishing messages to SAP Event Mesh on SAP BTP Cloud Foundry. Useful for interacting with event queues and topics directly from the CLI without needing an external client.

CF Event Mesh

Purpose

Use cf-event-mesh to interact with SAP Event Mesh (default plan, not Advanced Event Mesh) via the command line. It discovers credentials automatically from cf env <app-name> and allows you to listen to queues using AMQP or publish messages to queues/topics using REST.

If cf-event-mesh is missing, install it from @saptools/cf-event-mesh: npm install -g @saptools/cf-event-mesh.

First Steps

1. Determine the target Cloud Foundry app that is bound to the enterprise-messaging service.
2. Ensure you are currently logged in (cf login) and targeting the correct space (cf target -s <space> -o <org>) where the app resides.
3. Identify whether the user needs to listen to a queue or publish a message.

Command Choice

Use listen to subscribe to an AMQP queue and output incoming messages to stdout:

cf-event-mesh listen <app-name> <queue-name>
cf-event-mesh listen <app-name> <queue-name> --ack

Note on Acknowledgements: By default, the listener does NOT acknowledge messages (autoAck: false), meaning messages remain in the queue and can be processed by real consumers later. This is safe for debugging. Use the --ack flag if you explicitly want to acknowledge (remove) the messages from the queue as they are received.

Use publish to send a message payload to a topic or queue via REST:

cf-event-mesh publish <app-name> queue <queue-name> '{"hello":"world"}'
cf-event-mesh publish <app-name> topic <topic-name> '{"hello":"world"}'

The payload should be a valid string, typically JSON.

Output And State

• The listen command streams incoming AMQP messages to stdout. It will keep running until interrupted (Ctrl+C).
• The publish command outputs a success confirmation or an error message and then exits.
• Both commands fetch VCAP_SERVICES dynamically using cf curl /v3/apps/<guid>/env.

Do not paste credential values (like clientid, clientsecret, uri) in clear text when reporting back.

Behavior Notes

• cf-event-mesh relies on the enterprise-messaging service bindings inside the provided <app-name>.
• The CLI automatically handles OAuth2 token fetching using the clientid, clientsecret, and tokenendpoint from the service binding.
• For listen, it connects via AMQPS to the URI provided in the amqp10ws protocol array.
• For publish, it connects via HTTPS to the URI provided in the httprest protocol array.

Troubleshooting

If the command fails with App not found, verify that the app name is correct and you are targeting the correct CF space:

cf target
cf apps

If the command fails with No Event Mesh binding found, verify that the app is actually bound to an enterprise-messaging service instance:

cf services
cf env <app-name>

If publish fails with HTTP 403 Forbidden or 404 Not Found, ensure the topic or queue exists in the Event Mesh dashboard and the service key/binding has the appropriate publish rules (e.g., namespace prefixes).

If listen connects but receives no messages, verify the queue name (often prefixed with a namespace like company/app/1/MyQueue) and check if other consumers are actively pulling and acknowledging messages before the CLI can see them.