feat(perms): add SSE subscribe_bundles to BuilderTxCache (#131)

* feat(perms): add SSE subscribe_bundles to BuilderTxCache

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* chore: bump version to 0.18.0

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: Evalir

Cargo.toml

@@ -3,7 +3,7 @@ name = "init4-bin-base"
 
 description = "Internal utilities for binaries produced by the init4 team"
 keywords = ["init4", "bin", "base"]
-version = "0.18.0-rc.13"
+version = "0.18.0"
 edition = "2021"
 rust-version = "1.85"
 authors = ["init4", "James Prestwich", "evalir"]
@@ -15,8 +15,8 @@ repository = "https://github.com/init4tech/bin-base"
 init4-from-env-derive = { version = "0.2.0", path = "from-env-derive" }
 
 # Signet
-signet-constants = { version = "0.16.0-rc.11" }
-signet-tx-cache = { version = "0.16.0-rc.11", optional = true }
+signet-constants = { version = "0.16.0" }
+signet-tx-cache = { version = "0.16.0", optional = true }
 
 # alloy
 alloy = { version = "1.0.35", optional = true, default-features = false, features = ["std", "signer-local", "consensus", "network"] }
@@ -76,6 +76,7 @@ default = ["alloy", "rustls"]
 alloy = ["dep:alloy"]
 aws = ["alloy", "alloy?/signer-aws", "dep:async-trait", "dep:aws-config", "dep:aws-sdk-kms"]
 perms = ["dep:eyre", "dep:oauth2", "dep:tokio", "dep:reqwest", "dep:signet-tx-cache", "dep:futures-util"]
+sse = ["perms", "signet-tx-cache/sse"]
 pylon = ["perms", "alloy/kzg"]
 block_watcher = ["dep:tokio"]
 rustls = ["dep:rustls", "rustls/aws-lc-rs"]

src/perms/tx_cache.rs

@@ -39,6 +39,8 @@ impl From<url::ParseError> for BuilderTxCacheError {
 }
 
 const BUNDLES: &str = "bundles";
+#[cfg(feature = "sse")]
+const BUNDLES_FEED: &str = "bundles/feed";
 
 /// A client for interacting with the transaction cache, a thin wrapper around
 /// the [`TxCache`] and [`SharedToken`] that implements the necessary methods
@@ -188,3 +190,24 @@ impl BuilderTxCache {
             .map_err(Into::into)
     }
 }
+
+#[cfg(feature = "sse")]
+impl BuilderTxCache {
+    /// Subscribe to real-time bundle events via SSE.
+    ///
+    /// Connects to the `/bundles/feed` endpoint with bearer auth and
+    /// returns a [`Stream`] that yields each [`CachedBundle`] as it
+    /// arrives. The stream terminates on the first error, which is
+    /// yielded as the final item.
+    #[instrument(skip_all)]
+    pub async fn subscribe_bundles(
+        &self,
+    ) -> Result<impl Stream<Item = Result<CachedBundle>> + Send> {
+        let secret = self.token.secret().await?;
+        let stream = self
+            .tx_cache
+            .subscribe_inner::<CachedBundle>(BUNDLES_FEED, Some(&secret))
+            .await?;
+        Ok(stream.map(|r| r.map_err(Into::into)))
+    }
+}