Cargo features & platform support
boatramp is one binary of feature-gated crates, but the default build is
batteries-included: it enables every non-conflicting feature, so a plain
cargo build, the Nix/OCI images, and the release binaries all ship the full
capability set — there is no “the server was built without X”. This page lists the
cargo features (all default-on) and then which capabilities are Linux-only. To
build a minimal binary instead, see Build from source.
Cargo build features
Every feature below is on by default. The whole set composes (there are no
mutually-exclusive features; the runtime --blobs / --kv / --tls selectors
pick among the compiled-in backends), and the nightly --all-features gate proves
it. Should a feature ever genuinely conflict with another, it would be dropped
from the default and shipped as its own build variant.
For a minimal build, opt out and name only what you want:
cargo build --release -p boatramp --no-default-features --features fs,slatedb
Some features imply others: http3/acme-dns imply tls; cluster implies
handlers + slatedb; operator implies cluster; each sql-* and
orm-subquery imply handlers.
| Feature | Default | Enables |
|---|---|---|
fs | yes | Filesystem blob backend (--blobs fs). |
slatedb | yes | The default --kv slatedb: a durable transactional LSM over an object_store backend. |
s3 | yes | S3 blob backend (--blobs s3) + its S3→SQS blob-change notification provider. |
gcs | yes | Google Cloud Storage blob backend (--blobs gcs) + its GCS→Pub/Sub notification provider. |
azure | yes | Azure Blob Storage backend (--blobs azure) + its Event Grid→Storage Queue notification provider. |
cloudflare-kv | yes | Cloudflare KV metadata backend. |
tls | yes | HTTPS: --tls custom (operator cert) and --tls acme (automatic certs). |
acme-dns | yes | Wildcard TLS via ACME DNS-01 plus the dns subcommand (--tls acme-dns) and the pluggable DNS-provider clients. Implies tls. |
http3 | yes | HTTP/3 (QUIC) serving alongside the TLS TCP listener. Implies tls. |
oidc | yes | OIDC → token exchange: verify serve against an OIDC issuer’s JWKS. |
signer-aws | yes | External token signer backed by AWS KMS. |
signer-gcp | yes | External token signer backed by GCP KMS. |
signer-azure | yes | External token signer backed by Azure Key Vault. |
signer-vault | yes | External token signer backed by HashiCorp Vault. |
signer-pkcs11 | yes | External token signer backed by a PKCS#11 HSM. |
compression | yes | On-the-fly response compression, opt-in per site. |
bundler | yes | The in-process JS/TS + CSS bundler for boatramp bundle. |
handlers | yes | The wasmtime handler engine, component validation at sync, and the sql handler binding (with the typed orm query builder over the same databases). |
cluster | yes | Self-hosted Raft cluster mode. Implies handlers and slatedb. |
sql-postgres | yes | External (bring-your-own) PostgreSQL for the handler sql binding, opened by name. Implies handlers. |
sql-mysql | yes | External (bring-your-own) MySQL/MariaDB for the handler sql binding, opened by name. Implies handlers. |
orm-subquery | yes | The typed orm builder’s correlated roll-up (related_count/related_agg) and narrow scalar/IN subqueries — the one scalar-subquery form. Implies handlers; drop it to ship a host that refuses correlated subqueries. (pgvector distance and the rest of the orm surface are always compiled — not a cargo feature; pgvector is advertised to guests as the experimental orm-vector capability — a requires gate, not a build feature.) |
email | yes | The per-project SMTP email gateway: the boatramp:handlers/email guest capability + the boatramp email admin subcommand (host-held credentials, durable spool). Implies handlers; drop it for a build with no SMTP client. |
admin | yes | The guest project self-config capability boatramp:handlers/admin — a guest reconfigures its own project (domains / email / site / secrets) without a token, per-surface and posture-gated. Implies handlers; drop it for a build with no guest self-config. |
capability | yes | The guest capability-minting capability boatramp:handlers/capability — a guest mints a fleet-signed, own-project-only target capability (audience host-forced, TTL-clamped, deny-by-default). Implies handlers; drop it for a build with no guest capability minting. |
session | yes | The duplex guest session capability boatramp:handlers/session — a host-owned SSE-out + POST-in channel with host-managed ordering, resume, and lifetime. Implies handlers. |
console | yes | Bake the web management console (a Wasm SPA) into the binary; serve it at an operator-configured host+path ([serve.console]). On in every shipped build (release binaries + Nix/OCI images), which stage the built SPA in; a from-source build embeds a placeholder unless you build the SPA first with just console. |
mcp | yes | The Model Context Protocol server: the boatramp mcp stdio subcommand + the HTTP /mcp endpoint on serve. Also enables boatramp-server/mcp. |
Two more features are on by default but omitted from the table above:
domain-verify-dns (verify a host’s _boatramp-verify TXT over public DNS) and
operator (the in-binary Kubernetes operator; implies cluster).
The COSE/CWT + Cedar control-plane auth, the OCI→ext4 rootfs build, and the container / microVM / remote-docker compute backends are compiled into every build; they are not behind cargo features. The compute code that needs Linux is gated at the source level and compiles to no-ops elsewhere.
# A minimal build (filesystem blobs + embedded KV only).
cargo build --release -p boatramp --no-default-features --features fs,slatedb
Platform support
The publish / serve / handler / TLS / cluster core is cross-platform. The compute execution backends differ:
| Platform | Compute backends |
|---|---|
Linux x86_64, aarch64 | microVM (needs /dev/kvm), native container, remote-docker |
| macOS, Windows | remote-docker only |
The microVM and native-container backends need /dev/kvm, namespaces, and the
jailer, so they are Linux-only; on macOS and Windows that code compiles to
no-ops and compute runs through the remote-docker backend against a Linux Docker
host.
See also
- Build from source — toolchain and selecting features at build time.
- Install boatramp — prebuilt archives and packages.