diff --git a/Cargo.lock b/Cargo.lock
index d10a4ed..5d7b497 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -57,6 +57,12 @@ version = "0.22.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "72b3254f16251a8381aa12e40e3c4d2f0199f8c6508fbecb9d91f575e0fbb8c6"
 
+[[package]]
+name = "base64-ng"
+version = "1.0.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8452b0c98385f31f08318109d6e06a859f89e0c5e38aad6103f095443b063052"
+
 [[package]]
 name = "bitflags"
 version = "2.12.1"
@@ -1569,6 +1575,7 @@ checksum = "13c2bddecc57b384dee18652358fb23172facb8a2c51ccc10d74c157bdea3292"
 name = "swoosh"
 version = "0.2.1"
 dependencies = [
+ "base64-ng",
  "const_format",
  "futures",
  "http",
diff --git a/Cargo.toml b/Cargo.toml
index 09b8397..b8c365a 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -15,6 +15,7 @@ reqwest = { version = "0.13.3", features = ["form", "json", "blocking", "multipa
 rand = { version = "0.10.1" }
 time = { version = "0.3.47", features = ["formatting", "macros", "parsing", "serde"] }
 uuid = { version = "1.23.1", features = ["v4", "serde"] }
+base64-ng = { version = "1.0.6" }
 const_format = { version = "0.2.36" }
 josekit = { version = "0.10.3" }
 textsender_models = { git = "ssh://git@git.kundeng.us/phoenix/textsender-models.git", tag = "v0.3.0-20-15820d5505-111" }