Video editing from Go, without FFmpeg on your machine.

What running FFmpeg from Go usually costs

• A single static binary is often why Go was chosen, and shelling out to FFmpeg puts a system dependency back into the deployment.
• os/exec gives you an exit code and stderr, so a bad parameter is a string to parse rather than a typed error.
• The encode competes with the service for CPU on the same box, which is felt first by whatever else that box was doing.

Trim a clip and wait for the file

package main

import (
	"bytes"
	"encoding/json"
	"fmt"
	"net/http"
	"os"
	"time"
)

const base = "https://kinopipe.com/api/v1"

type job struct {
	JobID        string `json:"jobId"`
	Status       string `json:"status"`
	ErrorMessage string `json:"errorMessage"`
	Result       struct {
		Output struct {
			DownloadURL string `json:"downloadUrl"`
		} `json:"output"`
	} `json:"result"`
}

func call(method, url string, body any) (job, error) {
	var payload *bytes.Reader
	if body != nil {
		encoded, _ := json.Marshal(body)
		payload = bytes.NewReader(encoded)
	} else {
		payload = bytes.NewReader(nil)
	}
	request, err := http.NewRequest(method, url, payload)
	if err != nil {
		return job{}, err
	}
	request.Header.Set("Authorization", "Bearer "+os.Getenv("KINOPIPE_API_KEY"))
	request.Header.Set("Content-Type", "application/json")

	response, err := http.DefaultClient.Do(request)
	if err != nil {
		return job{}, err
	}
	defer response.Body.Close()

	var decoded job
	return decoded, json.NewDecoder(response.Body).Decode(&decoded)
}

func main() {
	started, err := call(http.MethodPost, base+"/tools/trim-video", map[string]any{
		"inputs":  []map[string]string{{"id": "main", "url": "https://example.com/interview.mp4"}},
		"options": map[string]int{"start": 12, "end": 48},
	})
	if err != nil {
		panic(err)
	}

	for {
		current, err := call(http.MethodGet, base+"/jobs/"+started.JobID, nil)
		if err != nil {
			panic(err)
		}
		if current.Status == "failed" {
			panic(current.ErrorMessage)
		}
		if current.Status == "succeeded" {
			fmt.Println(current.Result.Output.DownloadURL)
			return
		}
		time.Sleep(2 * time.Second)
	}
}

• Standard library only, so the binary stays single and static.
• A split job returns every segment under outputs rather than output, which is worth handling if you call split-video or split-video-by-scenes.
• Send an Idempotency-Key header when you retry, and the retry returns the original job instead of paying for a second render.

FAQ