Give every agent session its own VM.

Full dev environments on your own AWS account. Your repo, your secrets, your tools. Detach and it parks itself. Attach and it is back in about 20 seconds.

Get started View on GitHub

brew install kerem-kaynak/tap/pier

[main] 0:claude*"checkout-flow"

C-b d detach · idle sessions park themselves enter attach · n new · m resize · d delete

##Why pier

Coding agents changed what a dev environment is. A session is no longer you at one machine. It is an agent that runs for hours and wants its own branch, its own ports, its own docker daemon. And you want several at once. Every existing place to run them fights you:

[x] Your laptop. Sessions fight over ports and files. Closing the lid kills the run.
[x] Hosted agent platforms. Your code, your secrets, and your agent's credentials live on someone else's infra, billed by the seat.
[x] A cloud dev box. Bills 24/7 while the agent thinks and while you sleep. You still hand-build repo, auth, secrets, and tools for every session.

pier makes each session a micro-VM that manages its own lifecycle. One command launches an EC2 instance and drops you into tmux inside it, with:

[+] your repo on a fresh branch, uncommitted edits included
[+] Claude Code and Codex installed and authenticated
[+] your MCP servers configured
[+] your dev environment built by the repo's own setup script

##What you get

[+] Parks itself. An in-VM supervisor stops the instance once the agent goes quiet. The disk persists.
[+] Resumes in about 20 seconds. Files, branches, and credentials exactly as you left them.
[+] Sessions as hostnames. pier proxy serves the dev server at checkout-flow.pier:3000, mirrored on localhost too.
[+] One-command resize. Outgrown the box? One 40 second cycle swaps the instance type, disk intact.
[+] GitHub-first transfer. The VM fetches your repo straight from GitHub. Only secrets ride the tunnel.
[+] Per-repo baked images. pier bake snapshots your toolchain once. Creates drop to about 60-90 seconds.
[+] No control plane. No server, no database, no daemon. Session state lives in EC2 instance tags.
[+] One transport. Attach, exec, file push, and port forwards are all OpenSSH, direct or over an SSM tunnel.

##The numbers

Fig 1. create to ready in 42s, 52s from a baked image

Fig 2. parked sessions resume in about 20s

Fig 3. idle burn drops to disk-only storage prices

Session state	Costs
running	`~$0.03/h`
parked	`~$3-4/mo` (disk only)

##How it works

A session is one EC2 instance plus its EBS disk, tagged and namespaced by your caller identity. All state lives in those tags and on the disk. There is nothing else to operate, back up, or pay for.

laptop                              AWS account (yours)
──────                              ───────────────────
pier CLI/TUI ── aws cli ──────────▶ EC2 API        (create/stop/start/tags)
     │                              ┌─────────────────────────┐
     └── ssh ─────────────────────▶ │ session VM               │
         (direct to its public IP,  │  tmux ▸ claude / codex   │
          SSM tunnel as fallback)   │  pier-supervisor         │
                                    │  └─ parks the VM when    │
                                    │     detached and quiet   │
                                    └─────────────────────────┘

[+] The supervisor samples every 5 seconds for attached and busy. Detached and quiet past the idle timeout parks the VM.
[+] The VM holds no cloud credentials. Parking is the VM running shutdown -h now. Anything needing account credentials happens from the laptop.
[+] A runaway cap parks a looping agent anyway, so it cannot burn compute for days.

##vs. other tools

	pier	Codespaces	Hosted agents	DIY EC2
Runs on	your AWS account	GitHub's infra	vendor's sandbox	your AWS account
Idle cost	`~$3-4/mo` (self-parks)	metered, auto-stop	per-seat / per-task	full rate unless you script it
Agent-ready	harnesses + auth + MCP travel	you configure	their agent only	you configure
Session lifetime	until you `rm` it	workspace-scoped	task-scoped	until you clean it up
Interface	your terminal, tmux	VS Code / web	web UI	your terminal
Setup	one wizard	per-repo config	account signup	everything by hand

##FAQ

Does pier need a server or a database?

No. There is no control plane. Session state lives in EC2 instance tags, and pier ls is a filtered describe-instances call.

Does the VM hold my cloud credentials?

No. The instance role carries SSM and nothing else. Parking is the VM shutting itself down. Resize and destroy happen from the laptop.

What happens when I close my laptop?

The session keeps running without you. Once the agent goes quiet past the idle timeout, the supervisor parks the VM. Attach later and it resumes in about 20 seconds.

How do secrets travel?

Once, at create, as an explicit manifest: your agent configs, your tokens, and the repo files your .pier-include lists. Nothing loose ships by default, and the create prints which env files it is not carrying.

Do private repos work?

Yes. pier reuses whatever GitHub credential your laptop already has: a gh login, git's https credential helper, or ssh keys through a forwarded agent. It verifies the fetch works before relying on it.

What survives parking?

Files, git state, and installed tools survive. Running processes do not, parking is a clean stop. Hibernate with RAM intact is on the roadmap.

Which platforms?

The CLI runs on macOS and Linux against AWS. pier proxy is macOS-only for now, pier port works everywhere. A GCP driver is designed and parked on the roadmap.

How do I get rid of everything?

pier teardown removes every piece of account groundwork pier created, all of it tagged. Sessions go with pier rm.

Tie up at the pier.

One wizard, then every session is one command away.

brew install kerem-kaynak/tap/pier

Read the docs