MSRV Policy and Feature Flag Matrix
Minimum Supported Rust Version (MSRV)
Current MSRV: Rust 1.93
Defined in Cargo.toml under [workspace.package]:
rust-version = "1.93"All workspace members inherit this version. CI runs cargo test --workspace on the MSRV toolchain to ensure tests (not just compilation) pass.
MSRV Update Policy
- MSRV increases are treated as minor version bumps (SemVer).
- MSRV is only raised when a dependency update or language feature provides meaningful value (performance, safety, ergonomics).
- CI enforces MSRV on every push to
mainand on all pull requests.
Workspace Crates
| Crate | Description |
|---|---|
varpulis-actors | Actor framework with supervision |
varpulis-cli | Command-line interface and REST API |
varpulis-cluster | Distributed execution (Raft, K8s) |
varpulis-connector-api | Shared connector traits and types |
varpulis-connector-mqtt | MQTT connector |
varpulis-connector-kafka | Apache Kafka connector |
varpulis-connector-nats | NATS connector |
varpulis-connector-redis | Redis connector |
varpulis-connector-database | SQL database connector (PG/MySQL/SQLite) |
varpulis-connector-elasticsearch | Elasticsearch connector |
varpulis-connector-pulsar | Apache Pulsar connector |
varpulis-connector-kinesis | AWS Kinesis connector |
varpulis-connector-s3 | AWS S3 connector |
varpulis-connector-http | HTTP webhook connector |
varpulis-connector-cdc | PostgreSQL CDC connector |
varpulis-connectors | Convenience crate (re-exports all connectors) |
varpulis-core | Core types, AST, validation |
varpulis-datagen | Synthetic event generator |
varpulis-db | PostgreSQL persistence layer |
varpulis-lsp | Language Server Protocol |
varpulis-mcp | Model Context Protocol server |
varpulis-parser | VPL language parser |
varpulis-runtime | Execution engine |
varpulis-sase | SASE+ pattern matching |
varpulis-wasm | WebAssembly bindings |
Feature Flags
Features are disabled by default. Enable them via --features <flag>.
Connector Crates
Each connector is an independent crate with its own dependencies. They self-register via the inventory crate — linking a connector crate automatically makes it available to the engine. The varpulis-connectors crate re-exports all connectors via feature flags for backward compatibility.
| Crate | System | Key Dependency | Feature Flag |
|---|---|---|---|
varpulis-connector-mqtt | MQTT broker | rumqttc-v4-next 0.28 | mqtt |
varpulis-connector-kafka | Apache Kafka | rdkafka 0.39 | kafka |
varpulis-connector-nats | NATS messaging | async-nats 0.46 | nats |
varpulis-connector-redis | Redis | redis 1.x | redis |
varpulis-connector-database | SQL (PG + MySQL + SQLite) | sqlx 0.8 | database |
varpulis-connector-elasticsearch | Elasticsearch | elasticsearch 9.x | elasticsearch |
varpulis-connector-pulsar | Apache Pulsar | pulsar 6.x | pulsar |
varpulis-connector-s3 | AWS S3 | aws-sdk-s3 | s3 |
varpulis-connector-kinesis | AWS Kinesis | aws-sdk-kinesis | kinesis |
varpulis-connector-http | HTTP webhooks | axum, reqwest | http |
varpulis-connector-cdc | PostgreSQL CDC | tokio-postgres 0.7 | cdc |
All connector crates share varpulis-connector-api for the ConnectorFactory, Sink, ManagedConnector, and related traits.
Engine Features
| Feature | Description | Key Dependency |
|---|---|---|
persistence | RocksDB state persistence | rocksdb 0.22 |
binary-codec | MessagePack serialization | rmp-serde 1.3 |
encryption | AES-GCM state encryption | aes-gcm 0.10 |
onnx | ONNX ML inference | ort 2.0.0-rc.11 |
gpu | GPU acceleration (implies onnx) | ort |
WASM Features
| Feature | Description | Key Dependency |
|---|---|---|
smartmodule | SmartModule host runtime (filter/map) | wasmtime 48 |
MSRV exception:
wasmtime 48declaresrust-version = 1.95, and no release that fixes RUSTSEC-2026-0222 / RUSTSEC-2026-0269 builds on 1.93. The default workspace build stays on the 1.93 MSRV; enablingsmartmodule(orvarpulis-runtime/wasm-udf) requires rustc 1.95+, which is what the pinnedrust-toolchain.tomland the CI feature-flag matrix already use.
Cluster Features
These are defined in varpulis-cluster and exposed through varpulis-cli.
| Feature | Description | Key Dependency |
|---|---|---|
raft | Raft consensus | openraft 0.9 |
persistent | Raft + RocksDB (implies raft) | rocksdb 0.22 |
k8s | Kubernetes API | kube 0.98 |
nats-transport | NATS cluster transport | async-nats 0.38 |
federation | Multi-cluster (implies nats-transport) | - |
CLI Features
| Feature | Description |
|---|---|
saas | Multi-tenant SaaS mode |
oidc | OIDC/SSO authentication |
otel | OpenTelemetry observability |
Feature Dependency Graph
gpu ──► onnx
persistent ──► raft
federation ──► nats-transport
database ──► postgres + mysql + sqlite
all-connectors ──► mqtt + kafka + nats + database + redis
+ kinesis + s3 + elasticsearch + pulsarCI Feature Testing
Every feature flag is tested individually in CI via a matrix strategy:
cargo check --workspace --features <feature>
cargo clippy --workspace --all-targets --features <feature> -- -D warningsFeatures requiring system packages install them automatically. See .github/workflows/ci.yml for the full matrix.