Read when:
- changing AWS, Azure, Daytona, Google Cloud, or Hetzner provisioning;
- adding or wiring a new backend;
- adjusting machine classes, fallback order, regions, or images.
A provider is the backend that supplies the remote box a lease runs on. Crabbox
selects one with --provider <name> or the provider: config key, normalizing
aliases on the way in. Every built-in adapter lives under
internal/providers/<name> and is registered for its side effects in
internal/providers/all/all.go; the source-of-truth list of identifiers and
aliases is each adapter's provider.go (Name(), Aliases(), Spec()).
Each adapter declares a Spec that drives how Crabbox treats it:
- Kind —
ssh-lease(Crabbox provisions or connects to an SSH-reachable box and owns the full lifecycle, sync, run, and release),delegated-run(the provider owns sync and execution; there is no SSH lease), orservice-control(Crabbox can inspect or stop a provider-owned service, but cannot execute arbitrary run commands there). - Coordinator —
supportedmeans the provider may be brokered through either coordinator runtime;nevermeans it always runs direct from the CLI. Onlyaws,azure,daytona,gcp, andhetzneraresupported, and even those run direct unless a broker URL and token are configured (see Configuration andcrabbox config set-broker). - Targets — which runtime category the provider can satisfy. OS-backed
providers advertise Linux, macOS, or Windows; module/runtime providers can
advertise
worker-runtimewhen they execute source in a hosted runtime without SSH, POSIX shell, or filesystem sync semantics.
internal/cli/provider_backend.go defines the kinds, coordinator modes, and
feature flags; internal/cli/config.go holds the per-provider config sections
and the class-to-machine-type maps.
When an SSH-lease provider can be exercised from local credentials, add a
provider-specific path in scripts/live-smoke.sh. The smoke should use explicit
--provider routing for warmup, status, run, list, and stop, and its
remote command should not assume a particular project language unless it is
provider-specific.
If the provider is still unimplemented or the only credible proof is an
environment-specific local runbook, keep the smoke manual and document the real
acceptance contract first. Do not add a placeholder scripts/live-smoke.sh
branch that cannot run on a fresh operator machine with the documented
prerequisites.
Incus is the current example of an explicit opt-in local path: the default live
matrix still skips it, while CRABBOX_LIVE_PROVIDERS=incus and
CRABBOX_LIVE_DOCTOR_PROVIDERS=incus run the documented Apple Silicon / local
testbed contract when those prerequisites are actually present.
Use the canonical provider decision matrix to compare every built-in provider by execution model, access semantics, target OS, substrate, location, GPU orientation, cleanup behavior, best fit, and main caveat. The matrix is generated from the live CLI provider spec plus checked-in selection metadata, so registration and documentation drift fail the docs gate.
crabbox providers --json remains the low-level live spec. crabbox doctor
checks whether the selected provider is usable from the current environment.
--class standard|fast|large|beast (default beast) maps to an ordered list of
provider machine types. Crabbox tries each in turn, falling back when capacity or
quota rejects a request. The maps below come from internal/cli/config.go and
internal/cli/gcp.go:
Hetzner
standard ccx33, cpx62, cx53
fast ccx43, cpx62, cx53
large ccx53, ccx43, cpx62, cx53
beast ccx63, ccx53, ccx43, cpx62, cx53
AWS (Linux)
standard c7a.8xlarge, c7i.8xlarge, m7a.8xlarge, m7i.8xlarge, c7a.4xlarge
fast c7a.16xlarge, c7i.16xlarge, m7a.16xlarge, m7i.16xlarge, c7a.12xlarge, c7a.8xlarge
large c7a.24xlarge, c7i.24xlarge, m7a.24xlarge, m7i.24xlarge, r7a.24xlarge, c7a.16xlarge, c7a.12xlarge
beast c7a.48xlarge, c7i.48xlarge, m7a.48xlarge, m7i.48xlarge, r7a.48xlarge, c7a.32xlarge, c7i.32xlarge, m7a.32xlarge, c7a.24xlarge, c7a.16xlarge
AWS Windows (normal)
standard m7i.large, m7a.large, t3.large
fast m7i.xlarge, m7a.xlarge, t3.xlarge
large m7i.2xlarge, m7a.2xlarge, t3.2xlarge
beast m7i.4xlarge, m7a.4xlarge, m7i.2xlarge
AWS Windows WSL2
standard m8i.large, m8i-flex.large, c8i.large, r8i.large
fast m8i.xlarge, m8i-flex.xlarge, c8i.xlarge, r8i.xlarge
large m8i.2xlarge, m8i-flex.2xlarge, c8i.2xlarge, r8i.2xlarge
beast m8i.4xlarge, m8i-flex.4xlarge, c8i.4xlarge, r8i.4xlarge, m8i.2xlarge
AWS macOS (all classes)
mac2.metal, mac2-m2.metal, mac2-m2pro.metal, mac-m4.metal, mac-m4pro.metal,
mac-m4max.metal, mac2-m1ultra.metal, mac-m3ultra.metal, then mac1.metal unless
`--type` is set
Google Cloud
standard c4-standard-32, c3-standard-22, n2-standard-32, n2d-standard-32
fast c4-standard-64, c3-standard-44, n2-standard-64, n2d-standard-64, c4-standard-32
large c4-standard-96, c3-standard-88, n2-standard-80, n2d-standard-96, c4-standard-64
beast c4-standard-192, c4-standard-96, c3-standard-176, c3-standard-88, n2d-standard-224, n2-standard-128
Namespace Devbox
standard S
fast M
large L
beast XL
Cloudflare Containers (any class -> standard-4)
lite, basic, standard-1, standard-2, standard-3, standard-4
An explicit --type is treated as an exact provider type request. If that type
is rejected, Crabbox fails clearly instead of silently choosing a different
instance type. Drop --type and use a class when you want fallback. See
Capacity and fallback for the full fallback model.
DigitalOcean maps every class to the smallest Phase 1 default size
s-1vcpu-1gb. Use --type <droplet-size-slug> when you need a larger exact
Droplet size.
Linode maps every class to the smallest Phase 1 default size g6-standard-1.
Use --type <linode-type-slug> when you need a different exact instance type.
Vultr maps every class to the smallest Phase 1 default plan vc2-1c-1gb.
Use --type <vultr-plan-id> when you need a different exact instance type.
Scaleway maps every class to the smallest foundation default type DEV1-S.
Use --type <scaleway-commercial-type> when you need a different exact
Scaleway Instances commercial type. The live lifecycle backend is not
implemented yet, so this is a config/provider contract rather than a live
capacity fallback path in this branch.
- imports or reuses the lease SSH key;
- creates a server with Crabbox labels;
- uses the configured image and location;
- falls back across class server types when capacity or quota rejects a request;
- fetches server-type hourly prices when cost estimates need provider pricing.
- signs EC2 Query API calls inside the Worker;
- imports or reuses an EC2 key pair;
- creates or reuses the
crabbox-runnerssecurity group with SSH ingress limited to configured CIDRs or the request source IP; - launches one-time Linux Spot or On-Demand instances;
- launches native Windows Server leases with EC2Launch PowerShell user data, then
a post-SSH bootstrap for OpenSSH/Git/user setup;
--desktopadds TightVNC, auto-logon, and first-network flyout suppression; - launches EC2 Mac leases on available Dedicated Hosts with On-Demand capacity,
optionally pinned by
CRABBOX_HOST_IDorhostId(CRABBOX_AWS_MAC_HOST_IDandaws.macHostIdremain compatibility aliases); brokered pinning requires admin authentication; - tags instances, volumes, and Spot requests;
- falls back across broad C/M/R instance families, including account-policy and capacity rejections, and can fall back to a small burstable type when policy rejects high-core candidates;
- preflights applied Spot/On-Demand vCPU quotas in brokered mode when Service Quotas allows it, recording skipped candidates as quota attempts;
- honors
--market spot|on-demandonwarmupandrunfor one-off overrides; - uses Spot placement score across configured regions in direct mode and can fall back to On-Demand after Spot capacity/quota failures when configured;
- fetches Spot price history when cost estimates need provider pricing.
crabbox list marks brokered machines as orphan=no-active-lease when their
provider label references a lease no longer active in the coordinator. This is an
operator hint only; keep=true machines are never deleted automatically.
The structured quota preflight and provisioningAttempts metadata belong to the
brokered Worker path; direct AWS fallback can still retry provider types but
without that telemetry.
A minimal direct (no-coordinator) smoke looks like this:
tmp="$(mktemp)"
printf 'provider: hetzner\n' > "$tmp"
CRABBOX_CONFIG="$tmp" CRABBOX_COORDINATOR= crabbox warmup --provider hetzner --class standard --ttl 15m --idle-timeout 4m
CRABBOX_CONFIG="$tmp" CRABBOX_COORDINATOR= crabbox run --provider hetzner --id <slug> --no-sync -- echo direct-hetzner-ok
CRABBOX_CONFIG="$tmp" CRABBOX_COORDINATOR= crabbox stop --provider hetzner <slug>
rm -f "$tmp"Swap --provider aws (AWS SDK credentials) or --provider gcp (Google
Application Default Credentials) for direct cloud smoke. The direct GCP path uses
Google's Compute Go SDK and project-wide aggregated instance listing for resolve,
list, and cleanup.
- proxmox — clones a configured Linux QEMU template, injects SSH via
cloud-init, discovers the IP and bootstraps through the QEMU guest agent, then
uses normal Crabbox SSH sync/run/release. Configure with
CRABBOX_PROXMOX_*/ theproxmoxconfig section. - firecracker — currently exposes the self-hosted Linux KVM provider
contract and a read-only doctor surface. It validates the host OS,
/dev/kvm, the configured Firecracker binary, kernel/rootfs files, and CNI directories without starting a microVM. Configure withCRABBOX_FIRECRACKER_*/ thefirecrackerconfig section. - parallels — creates a linked clone from a configured source VM and optional
snapshot, starts it, discovers the guest IP through
prlctl, then uses normal SSH sync/run/release. Supports Linux, macOS, and Windows guests that already expose the matching SSH contract. Configure withCRABBOX_PARALLELS_*. - local-container (alias
docker) — starts a labeled container on a local Docker-compatible runtime, publishes SSH on loopback, syncs over SSH, and removes it onstop. It detects an installeddockerorpodmanCLI; if both are present,dockeris selected unlesslocalContainer.runtimeis set explicitly. Cache volumes use named volumes. It does not bind-mount the repo or the Docker-compatible socket by default. ReadsDOCKER_HOSTfor socket pass-through. - multipass (alias
mp) — launches a local Ubuntu VM through Canonical Multipass with cloud-init, resolves the VM IP throughmultipass info, syncs over SSH, and deletes the VM withmultipass delete --purge. Cache volumes are host directories mounted into the VM. - daytona — creates a sandbox from
daytona.snapshot, syncs and runs through Daytona's SDK/toolbox APIs, and mints short-lived SSH tokens only for explicitcrabbox sshaccess. - exe-dev — exe.dev owns auth and lifecycle through
ssh exe.dev; Crabbox treats the returnedssh_destas a normal Linux SSH lease (public SSH only, no Tailscale). - kubevirt — applies a standard KubeVirt
VirtualMachine, controls it withvirtctl, and carries SSH, rsync, and desktop tunnels throughvirtctl port-forward --stdio. - external — invokes a configured executable for lifecycle operations and consumes the returned SSH target. Provider-specific logic and credentials remain outside Crabbox.
- namespace-devbox — Namespace owns Devbox auth and lifecycle through the
devboxCLI; Crabbox treats the prepared Devbox as a normal Linux SSH lease. - nebius — creates a Nebius Compute VM through the authenticated
nebiusCLI, injects a per-lease SSH key with cloud-init, waits for dynamic public IPv4 and SSH readiness, then uses normal Crabbox SSH sync/run/release. - runpod — leases a RunPod GPU pod with public SSH (no Tailscale); auth from
RUNPOD_API_KEY. - semaphore — creates a standalone Semaphore job, waits for host/port metadata and a debug SSH key, then runs the standard SSH path. Use it to run in the same machine image, secret context, and cache plane as Semaphore CI.
- sprites — creates a sprite, installs OpenSSH and rsync inside it, and reaches
SSH through
sprite proxyfor a fast Linux microVM on the standard SSH path. - scaleway — is registered as a direct Linux SSH-lease provider for Scaleway
Instances with Scaleway SDK credentials, per-lease managed IAM SSH keys,
cloud-init bootstrap, Crabbox-owned tags, and direct cleanup.
doctorchecks SDK config and auth material discovery without creating resources.
Delegated-run providers (cloudflare, cloudflare-sandbox,
azure-dynamic-sessions, blaxel, e2b, islo, modal, tensorlake,
upstash-box, blacksmith-testbox, wandb, opensandbox, superserve, and
vercel-sandbox) do not use the broker for run execution; each owns sandbox
lifecycle and command execution and syncs through its own API (gzipped archive
upload for most). Islo also exposes a direct crabbox ssh login helper for
kept sandboxes at <sandbox>.islo, but Islo run/sync remains delegated. See the
linked provider pages for per-provider auth and configuration.
Module-runtime delegated providers are a narrower category for Worker-isolate
style runtimes. They should advertise target=worker-runtime and
feature=module-run, accept crabbox run --script <file> or
--script-stdin as source module input, and reject trailing -- <command>
argv rather than implying Linux shell semantics. A module-runtime target does
not imply SSH, rsync, archive sync, VNC, browser desktop, code-server, ports, or
POSIX filesystem behavior unless a provider explicitly documents and advertises
those capabilities.
cloudflare-dynamic-workers is the Cloudflare-family module-runtime provider.
It is distinct from cloudflare, which runs Linux commands in Cloudflare
Containers, and from cloudflare-sandbox, which runs Linux commands through a
configured Cloudflare Sandbox bridge. Dynamic Workers support module-run,
local claim cleanup, and run-session metadata, but not SSH, Crabbox sync,
Actions hydration, browser, desktop, code-server, ports, or container instance
classes.
provider: ssh (aliases static, static-ssh) attaches to a preexisting host —
no provisioning, no cleanup:
provider: ssh
target: macos
static:
host: mac-studio.local
user: alice
port: "22"
workRoot: /Users/alice/crabboxprovider: ssh
target: windows
windows:
mode: normal
static:
host: win-dev.local
user: alice
port: "22"
workRoot: C:\crabboxtarget: windows supports windows.mode: normal and windows.mode: wsl2:
- normal uses PowerShell over OpenSSH and syncs the manifest as a tar archive.
- wsl2 keeps the POSIX SSH contract: commands run through
wsl.exe --exec bash -lc, rsync useswsl.exe rsync, andstatic.workRootshould be a WSL path such as/home/alice/crabbox. Managed AWS WSL2 leases need nested virtualization, so they use the C8i/M8i/R8i families and enable nested virtualization at launch.
macOS also uses the POSIX contract and needs git, rsync, tar, and SSH.
Use --tailscale to add tailnet reachability to new managed Linux leases, or
point a static host at a MagicDNS name / 100.x address when the host is already
on a tailnet. See Tailscale.