Configuration

pier setup writes ~/.config/pier/config.toml. Change any setting later from the TUI settings page. Run pier and press s.

driver = "aws-ec2"
idle_timeout = "30m"      # detached and quiet this long -> park ("never" disables)
unattended_cap = "8h"     # parks even while busy ("never" disables)

[aws]
profile = "default"
region = "eu-central-1"
instance_type = "t4g.medium"   # machine for new sessions
disk_gib = 40
subnet = ""                    # optional: orgs without a default VPC
direct = true                  # ssh straight to the VM. false forces the SSM tunnel

Keys

Key	Default	Meaning
driver	aws-ec2	the cloud driver (GCP is on the roadmap)
idle_timeout	30m	detached and quiet this long parks the VM, never disables
unattended_cap	8h	parks even while busy, so a looping agent can’t burn compute for days
aws.profile		the AWS CLI profile pier calls with
aws.region		where sessions run
aws.instance_type	t4g.medium	machine for new sessions
aws.disk_gib	40	EBS disk size per session
aws.subnet		optional, for orgs without a default VPC
aws.direct	true	ssh straight to the instance’s public IP, port 22 open to your IP only, SSM tunnel as fallback. false forces the tunnel

Per-session overrides beat the config: --idle and --cap at create time.

Managed sections

Two sections are managed by pier, not by hand:

• [aws.baked_amis] maps repo basenames to baked images. pier bake writes it, pier teardown sweeps the images.
• [secrets] holds the manifest of files and dirs under $HOME copied one-way into each session at create, plus an optional claude_oauth_token from claude setup-token (the macOS Keychain escape hatch, injected as CLAUDE_CODE_OAUTH_TOKEN in sessions).