spore.host

Appearance

Frequently Asked Questions ​

General ​

What is spore.host? ​

spore.host is a set of free, open-source tools for launching ephemeral EC2 instances that manage their own lifecycle. Every instance you launch gets a time-to-live and an idle detector — the TTL terminates it when the deadline passes, and idle detection stops it between tasks — so you never pay for idle compute by accident.

What's the difference between truffle and spawn? ​

Truffle is read-only — it finds and compares instance types, Spot prices, and quotas. Think of it as search and research before you commit.

Spawn is the launcher — it provisions instances, installs spored, and manages the full lifecycle.

What is spored? ​

Spored is a small daemon that runs on each spawned instance. It enforces the TTL, detects idle conditions, handles Spot interruptions, registers a DNS name, and sends lifecycle notifications to Slack or Teams. It runs independently of your laptop — you can close your terminal and spored keeps working.

Is spore.host free? ​

Yes. The CLI tools (truffle, spawn, lagotto, spore-host-mcp) are free and open source (Apache 2.0). You pay only for the AWS resources you use — EC2 instance hours, storage, and data transfer. spore.host helps minimise these costs through TTL enforcement and idle detection.

AWS and costs ​

How does spore.host prevent surprise bills? ​

Every instance launched through spawn has a TTL — a hard deadline at which it terminates. Idle detection adds an earlier soft cutoff: if the instance has been unused for a configured period, it stops or hibernates before the TTL fires. You set both at launch time, or save them as defaults.

Can I use spore.host with multiple AWS accounts? ​

Yes. Use AWS_PROFILE=my-profile spawn launch ... or spawn launch --profile my-profile ... to specify which credential profile to use per launch.

What AWS permissions does spore.host need? ​

The minimum policy is documented at IAM Permissions. In brief: EC2 describe, run, stop, terminate, tag, and create tags; IAM pass-role for the spored instance profile; Route53 for DNS registration.

Instances ​

What instance types are supported? ​

All EC2 instance types. Common choices for research:

  • General purpose: m7i.large, m7i.xlarge
  • CPU-intensive: c7i.2xlarge, c6i.4xlarge
  • Memory-intensive: r7i.2xlarge, r6i.8xlarge
  • GPU (training): p4d.24xlarge, g5.2xlarge
  • GPU (inference): g5.xlarge, g4dn.xlarge
  • Free tier: t3.micro, t2.micro

Can I use a custom AMI? ​

Yes: spawn launch --ami ami-XXXXXXXXX. Spored is installed via user-data at launch, so it works with any Amazon Linux 2, Amazon Linux 2023, or Ubuntu AMI.

Can I extend the TTL after launch? ​

Yes, at any time: spawn extend my-instance 4h — or from Slack: /spore extend my-instance 4h.

What's the maximum TTL? ​

720 hours (30 days). Setting --ttl 0 disables auto-termination, which is not recommended for anything other than long-lived development environments.

What happens to a Spot instance when AWS interrupts it? ​

Spored receives the two-minute warning via the EC2 metadata service. It runs your --pre-stop hook if configured (for saving checkpoints), sends a Slack notification, and terminates gracefully.

SSH and connectivity ​

How do I connect? ​

sh
spawn connect my-instance   # prints the SSH command

Or directly: ssh ec2-user@<public-ip>

How do I find the key? ​

Spawn creates a key pair named spawn-default on first use and saves the private key to ~/.spawn/keys/spawn-default.pem. Use it with -i ~/.spawn/keys/spawn-default.pem if needed.

Why does SSH fail right after launch? ​

The instance takes 30–90 seconds to boot and start sshd. Wait and retry.

Can I use my existing SSH key? ​

Yes: spawn launch --key-name my-existing-keypair

Idle detection ​

Why didn't my instance terminate when I expected it to? ​

Idle detection considers CPU, network I/O, disk I/O, GPU utilisation, active SSH sessions, and (if configured) specific process names. If any signal indicates activity, the idle timer resets. Check spawn status my-instance to see current activity levels.

I'm running RStudio — why does idle detection keep resetting? ​

The RStudio browser tab maintains a TCP connection to the server even when you're not actively using it. Use --active-processes rsession to base idle detection on whether an R session process is actually running, rather than TCP connections.

Can I disable idle detection? ​

Yes: spawn launch --idle-timeout 0. The TTL still applies as the hard outer bound.

Slack / Teams ​

Do I need to set up Slack to use spore.host? ​

No. Slack and Teams integration is optional. spore.host works fully without it — you just won't get DM notifications or slash command control.

Can multiple people control the same instance from Slack? ​

Yes. Register each user separately with spawn notify register, granting them the actions they need. Each person can then use /spore status, /spore stop, etc. on that instance.

Something stopped working after I updated the Slack app scopes. ​

Updating app scopes regenerates the signing secret. Re-register with the new secret: spawn notify workspace-add --platform slack --workspace-id T0... --signing-secret <new-secret>