feat(datadog-ffe): server-side EVP flagevaluation payload + bincode-safe sidecar delivery

datadog-ffe/Cargo.toml

@@ -20,6 +20,9 @@ derive_more = { version = "2.0.0", default-features = false, features = ["from",
 log = { version = "0.4.21", default-features = false, features = ["kv", "kv_serde"] }
 md5 = { version = "0.7.0", default-features = false }
 libdd-common = { version = "4.2.0", path = "../libdd-common", default-features = false, features = ["require-regex-full"] }
+libdd-capabilities = { path = "../libdd-capabilities", version = "2.0.0", optional = true }
+http = { version = "1.1", optional = true }
+tokio = { version = "1.49.0", features = ["time"], optional = true }
 semver = "1.0"
 serde-bool = { version = "0.1.3", default-features = false }
 serde_with = { version = "3.11.0", default-features = false, features = ["base64", "hex", "macros"] }
@@ -30,9 +33,18 @@ libdd-trace-protobuf = { path = "../libdd-trace-protobuf", optional = true }
 prost = { version = "0.14.1", optional = true }
 pyo3 = { version = "0.28", optional = true, default-features = false, features = ["macros"] }
 
+[dev-dependencies]
+# Matches the sidecar's bincode version. Used by the flagevaluation bincode
+# round-trip test, which guards against `skip_serializing_if` reintroducing the
+# worker→sidecar IPC field-misalignment bug (bincode is non-self-describing).
+bincode = { version = "1.3.3" }
+httpmock = "0.8.0-alpha.1"
+libdd-capabilities-impl = { path = "../libdd-capabilities-impl" }
+
 [features]
 default = ["remote-config"]
 exposure-events = ["dep:lru"]
 evaluation-metrics = ["dep:libdd-trace-protobuf", "dep:prost"]
+flagevaluation-evp = ["dep:http", "dep:libdd-capabilities", "dep:tokio"]
 pyo3 = ["dep:pyo3"]
 remote-config = ["dep:libdd-remote-config"]

datadog-ffe/src/lib.rs

@@ -6,7 +6,11 @@ mod flag_type;
 #[cfg(feature = "remote-config")]
 mod remote_config;
 pub mod rules_based;
-#[cfg(any(feature = "exposure-events", feature = "evaluation-metrics"))]
+#[cfg(any(
+    feature = "exposure-events",
+    feature = "evaluation-metrics",
+    feature = "flagevaluation-evp"
+))]
 pub mod telemetry;
 
 pub use flag_type::{ExpectedFlagType, FlagType};