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Getting Started ​

Verified against sdk-go at commit 1e99396. Commands assume Go is installed; the v2/go.mod module declares go 1.25.0.

Prerequisites ​

  • Go 1.25 or newer (the v2 module sets go 1.25.0 in v2/go.mod).
  • A reachable HTTP endpoint to receive events, or the receiver from the second step below.

Install ​

bash
go get github.com/cloudevents/sdk-go/v2

A first working setup ​

The shortest path that does the core job is to send a CloudEvent over HTTP and receive it. This minimal sender is reduced from samples/http/sender/main.go.

Step 1. Create a sender. WithTimeNow and WithUUIDs fill in the time and id attributes so the event passes validation. The target endpoint is set as http://localhost:8080/ in code.

go
package main

import (
    "context"
    "log"

    cloudevents "github.com/cloudevents/sdk-go/v2"
)

func main() {
    ctx := cloudevents.ContextWithTarget(context.Background(), "http://localhost:8080/")

    p, err := cloudevents.NewHTTP()
    if err != nil {
        log.Fatal(err)
    }
    c, err := cloudevents.NewClient(p, cloudevents.WithTimeNow(), cloudevents.WithUUIDs())
    if err != nil {
        log.Fatal(err)
    }

    e := cloudevents.NewEvent()
    e.SetType("com.example.sent")
    e.SetSource("example/sender")
    _ = e.SetData(cloudevents.ApplicationJSON, map[string]string{"msg": "hello"})

    if res := c.Send(ctx, e); cloudevents.IsUndelivered(res) {
        log.Printf("failed: %v", res)
    }
}

Step 2. Run a receiver in a second program to see the event arrive. StartReceiver binds the HTTP listener and dispatches each event to the handler.

go
package main

import (
    "context"
    "log"

    cloudevents "github.com/cloudevents/sdk-go/v2"
)

func main() {
    c, err := cloudevents.NewClientHTTP()
    if err != nil {
        log.Fatal(err)
    }
    log.Fatal(c.StartReceiver(context.Background(), func(e cloudevents.Event) {
        log.Printf("got event: %s", e)
    }))
}

Step 3. Start the receiver, then run the sender in another shell.

bash
go run ./receiver
go run ./sender

Verify it works ​

The receiver logs the event it got, including the id, source, type, and the JSON data. On the sender side, cloudevents.IsUndelivered(res) returns false for a delivered event, so no failure line is printed. If the receiver is not running, the sender logs a failed: line with the transport error.

Where to go next ​