diff --git a/crates/reqsign/src/sign/api.rs b/crates/reqsign/src/sign/api.rs
index 8c8827d..3ec20a1 100644
--- a/crates/reqsign/src/sign/api.rs
+++ b/crates/reqsign/src/sign/api.rs
@@ -2,13 +2,13 @@ use super::SigningRequest;
 use std::fmt::Debug;
 use std::time::Duration;
 
-/// Context is the trait used by signer as the signing context.
-pub trait Context: Clone + Debug + Send + Sync + Unpin + 'static {
-    /// Check if the context is valid.
+/// Key is the trait used by signer as the signing key.
+pub trait Key: Clone + Debug + Send + Sync + Unpin + 'static {
+    /// Check if the key is valid.
     fn is_valid(&self) -> bool;
 }
 
-impl<T: Context> Context for Option<T> {
+impl<T: Key> Key for Option<T> {
     fn is_valid(&self) -> bool {
         let Some(ctx) = self else {
             return false;
@@ -18,34 +18,34 @@ impl<T: Context> Context for Option<T> {
     }
 }
 
-/// Load is the trait used by signer to load the context from the environment.
+/// Load is the trait used by signer to load the key from the environment.
 ///
-/// Service may require different context to sign the request, for example, AWS require
+/// Service may require different key to sign the request, for example, AWS require
 /// access key and secret key, while Google Cloud Storage require token.
 #[async_trait::async_trait]
 pub trait Load: Debug + Send + Sync + Unpin + 'static {
-    /// Context returned by this loader.
+    /// Key returned by this loader.
     ///
     /// Typically, it will be a credential.
-    type Context: Send + Sync + Unpin + 'static;
+    type Key: Send + Sync + Unpin + 'static;
 
-    /// Load signing context from current env.
-    async fn load(&self) -> anyhow::Result<Option<Self::Context>>;
+    /// Load signing key from current env.
+    async fn load(&self) -> anyhow::Result<Option<Self::Key>>;
 }
 
 /// Build is the trait used by signer to build the signing request.
 #[async_trait::async_trait]
 pub trait Build: Debug + Send + Sync + Unpin + 'static {
-    /// Context used by this builder.
+    /// Key used by this builder.
     ///
     /// Typically, it will be a credential.
-    type Context: Send + Sync + Unpin + 'static;
+    type Key: Send + Sync + Unpin + 'static;
 
     /// Construct the signing request.
     ///
-    /// ## Context
+    /// ## Key
     ///
-    /// The `ctx` parameter is the context required by the signer to sign the request.
+    /// The `key` parameter is the key required by the signer to sign the request.
     ///
     /// ## Expires In
     ///
@@ -57,7 +57,7 @@ pub trait Build: Debug + Send + Sync + Unpin + 'static {
     async fn build(
         &self,
         req: &mut http::request::Parts,
-        ctx: Option<&Self::Context>,
+        key: Option<&Self::Key>,
         expires_in: Option<Duration>,
     ) -> anyhow::Result<SigningRequest>;
 }
diff --git a/crates/reqsign/src/sign/mod.rs b/crates/reqsign/src/sign/mod.rs
index cc6c2b4..f863576 100644
--- a/crates/reqsign/src/sign/mod.rs
+++ b/crates/reqsign/src/sign/mod.rs
@@ -1,6 +1,6 @@
 mod api;
 pub use api::Build;
-pub use api::Context;
+pub use api::Key;
 pub use api::Load;
 
 mod request;
diff --git a/crates/reqsign/src/sign/signer.rs b/crates/reqsign/src/sign/signer.rs
index 10d9096..9e19d4d 100644
--- a/crates/reqsign/src/sign/signer.rs
+++ b/crates/reqsign/src/sign/signer.rs
@@ -1,23 +1,23 @@
-use crate::{Build, Context, Load};
+use crate::{Build, Key, Load};
 use anyhow::Result;
 use std::sync::{Arc, Mutex};
 use std::time::Duration;
 
 /// Signer is the main struct used to sign the request.
 #[derive(Clone, Debug)]
-pub struct Signer<Ctx: Context> {
-    loader: Arc<dyn Load<Context = Ctx>>,
-    builder: Arc<dyn Build<Context = Ctx>>,
-    context: Arc<Mutex<Option<Ctx>>>,
+pub struct Signer<K: Key> {
+    loader: Arc<dyn Load<Key = K>>,
+    builder: Arc<dyn Build<Key = K>>,
+    key: Arc<Mutex<Option<K>>>,
 }
 
-impl<Ctx: Context> Signer<Ctx> {
+impl<K: Key> Signer<K> {
     /// Create a new signer.
-    pub fn new(loader: impl Load<Context = Ctx>, builder: impl Build<Context = Ctx>) -> Self {
+    pub fn new(loader: impl Load<Key = K>, builder: impl Build<Key = K>) -> Self {
         Self {
             loader: Arc::new(loader),
             builder: Arc::new(builder),
-            context: Arc::new(Mutex::new(None)),
+            key: Arc::new(Mutex::new(None)),
         }
     }
 
@@ -27,16 +27,16 @@ impl<Ctx: Context> Signer<Ctx> {
         req: &mut http::request::Parts,
         expires_in: Option<Duration>,
     ) -> Result<()> {
-        let ctx = self.context.lock().expect("lock poisoned").clone();
-        let ctx = if ctx.is_valid() {
-            ctx
+        let key = self.key.lock().expect("lock poisoned").clone();
+        let key = if key.is_valid() {
+            key
         } else {
             let ctx = self.loader.load().await?;
-            *self.context.lock().expect("lock poisoned") = ctx.clone();
+            *self.key.lock().expect("lock poisoned") = ctx.clone();
             ctx
         };
 
-        let signing = self.builder.build(req, ctx.as_ref(), expires_in).await?;
+        let signing = self.builder.build(req, key.as_ref(), expires_in).await?;
         signing.apply(req)
     }
 }