Build Spec

When you deploy a service on Zeabur, the build and the runtime happen on two different machines. This page describes the build side.

TL;DR — Your code is built on Zeabur’s shared CI/CD infrastructure, not on the machine where your service runs. Build Spec only affects how fast the build completes; it has no effect on your running service.

Where Zeabur builds your code

Every deploy triggers a build job on Zeabur’s shared CI/CD infrastructure. The job:

  1. Pulls your source code (from Git, CLI upload, or container image source)
  2. Resolves a build plan with zbpack
  3. Builds a container image
  4. Pushes the image to Zeabur’s registry

The build machine is ephemeral — once the image is pushed, the build machine is released. It never runs your service.

Where your service actually runs

After the image is built, Zeabur deploys it to your chosen runtime infrastructure:

  • Shared Cluster — Zeabur-managed nodes (AWS / GCP / Tencent Cloud), sized per your plan
  • Dedicated Server — a server you rent through Zeabur or bring yourself under BYOS

The CPU, memory, network, and storage available to your service at runtime are determined by that infrastructure — not by anything about the build machine.

Build Spec by plan

Higher plans route builds to larger build machines, so builds finish faster:

PlanBuild CI
Free2 vCPU / 4 GB
Dev2 vCPU / 4 GB
Pro4 vCPU / 8 GB
Team4 vCPU / 8 GB

See Plans and zeabur.com/pricing for the latest allocations.

Does Build Spec affect my service’s performance?

No. Build Spec determines how fast your code compiles and packages, nothing else. It does not affect:

  • Request latency
  • Memory or CPU available at runtime
  • Concurrency or connection limits
  • Uptime or availability

If your running service is slow or being throttled, check your service’s runtime metrics and the plan / server it is deployed on instead.