Make Iggy the default provider

CHANGELOG.md

@@ -8,6 +8,13 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### ⚠️ Operational migrations
 
+- **The default provider is now Iggy.** The default feature set is
+  `iggy, encryption, cloudevents, routing`; NATS becomes opt-in via the
+  `nats` feature. Consumers that relied on the default providing NATS must
+  add `features = ["nats"]`. Note the known upstream Iggy restart issue
+  (apache/iggy#4361) before choosing Iggy for production restart-heavy
+  deployments.
+
 - **NATS durable consumer names are now sanitized.** `EventBus` used to build
   consumer names as `{subscriber}-{subject with '.'→'-'}`; subjects also
   contain `*` and `>`, which JetStream rejects outright (`error 10103`). The

Cargo.toml

@@ -16,7 +16,7 @@ name = "a3s_event"
 path = "src/lib.rs"
 
 [features]
-default = ["nats", "encryption", "cloudevents", "routing"]
+default = ["iggy", "encryption", "cloudevents", "routing"]
 nats = ["dep:async-nats", "dep:time", "dep:futures-util"]
 iggy = ["dep:iggy", "dep:bytes"]
 encryption = ["dep:aes-gcm", "dep:base64"]

README.md

@@ -60,8 +60,8 @@ All optional modules are behind feature gates. The minimal core (types, memory p
 
 | Feature | Default | Description |
 |---------|---------|-------------|
-| `nats` | ✅ | NATS JetStream provider (`async-nats`, `futures-util`, `time`) |
-| `iggy` | — | Apache Iggy provider (`iggy`, `bytes`) |
+| `iggy` | ✅ | Apache Iggy provider (`iggy`, `bytes`) — the default backend |
+| `nats` | — | NATS JetStream provider (`async-nats`, `futures-util`, `time`) |
 | `encryption` | ✅ | AES-256-GCM payload encryption (`aes-gcm`, `base64`) |
 | `cloudevents` | ✅ | CloudEvents v1.0 conversion (`chrono`) |
 | `routing` | ✅ | Broker/Trigger event routing + Sink DLQ |
@@ -83,8 +83,8 @@ a3s-event = { version = "0.3", default-features = false, features = ["nats", "en
 | Provider | Use Case | Persistence | Distribution |
 |----------|----------|-------------|--------------|
 | `MemoryProvider` | Testing, development, single-process | In-process only | Single process |
-| `NatsProvider` | Production, multi-service | JetStream (file/memory) | Distributed |
-| `IggyProvider` | Production, multi-service, Rust-native broker | Iggy stream (per-topic log) | Distributed |
+| `IggyProvider` | **Default.** Production, multi-service, Rust-native broker | Iggy stream (per-topic log) | Distributed |
+| `NatsProvider` | Opt-in (`nats` feature). Production, multi-service | JetStream (file/memory) | Distributed |
 
 ### Memory Provider
 

src/lib.rs

@@ -35,8 +35,8 @@
 //! ## Providers
 //!
 //! - **memory** — In-memory provider for testing and single-process use
-//! - **nats** — NATS JetStream for distributed, persistent event streaming
-//! - **iggy** — Apache Iggy for persistent, distributed event streaming
+//! - **iggy** — Apache Iggy (DEFAULT) for persistent, distributed event streaming
+//! - **nats** — NATS JetStream, opt-in via the `nats` feature
 //!
 //! ## Architecture
 //!

tests/e2e_chaos_resilience.rs

@@ -250,8 +250,12 @@ async fn iggy_personal_access_token_login_flows_end_to_end() {
         .with_server_address("127.0.0.1:5102".to_string())
         .build()
         .unwrap();
-    if let Err(e) = admin.login_user("iggy", "iggy").await {
-        eprintln!("Iggy unavailable ({e}), skipping PAT test");
+    // The raw SDK dial has no built-in bound (the provider wraps its own
+    // connect in a timeout) — bound it here so a dead server skips instead
+    // of hanging the default-feature test run.
+    let login = tokio::time::timeout(Duration::from_secs(5), admin.login_user("iggy", "iggy"));
+    if let Err(_) | Ok(Err(_)) = login.await {
+        eprintln!("Iggy unavailable, skipping PAT test");
         return;
     }
     let pat = match admin