diff --git a/lib/komainu/benches/pkce.rs b/lib/komainu/benches/pkce.rs
index 1fac7c6b8..d62e02755 100644
--- a/lib/komainu/benches/pkce.rs
+++ b/lib/komainu/benches/pkce.rs
@@ -6,7 +6,7 @@ use std::borrow::Cow;
 static GLOBAL: divan::AllocProfiler = divan::AllocProfiler::system();
 
 #[divan::bench]
-fn s256() -> Result<(), komainu::flow::FlowError> {
+fn s256() -> Result<(), komainu::flow::Error> {
     let verifier_base64 = "dBjftJeZ4CVP-mB92K27uhbUJU1p1r_wW1gFWFOEjXk";
     let challenge_base64 = "E9Melhoa2OwvFrEMTJguCHaoeK1t8URWbuGJSstw-cM";
 
@@ -19,7 +19,7 @@ fn s256() -> Result<(), komainu::flow::FlowError> {
 }
 
 #[divan::bench]
-fn none() -> Result<(), komainu::flow::FlowError> {
+fn none() -> Result<(), komainu::flow::Error> {
     let value = "arbitrary value";
 
     let payload = pkce::Payload {
diff --git a/lib/komainu/src/flow/authorization.rs b/lib/komainu/src/flow/authorization.rs
index 4e60f73dc..18b738787 100644
--- a/lib/komainu/src/flow/authorization.rs
+++ b/lib/komainu/src/flow/authorization.rs
@@ -1,6 +1,6 @@
 use crate::{
     extract::ClientCredentials,
-    flow::{FlowError, OptionExt, TokenResponse},
+    flow::{self, OptionExt, TokenResponse},
     params::ParamStorage,
     Authorization, ClientExtractor,
 };
@@ -11,12 +11,12 @@ pub trait Issuer {
     fn load_authorization(
         &self,
         auth_code: &str,
-    ) -> impl Future<Output = Result<Option<Authorization<'_>>, FlowError>> + Send;
+    ) -> impl Future<Output = Result<Option<Authorization<'_>>, flow::Error>> + Send;
 
     fn issue_token(
         &self,
         authorization: &Authorization<'_>,
-    ) -> impl Future<Output = Result<TokenResponse<'_>, FlowError>> + Send;
+    ) -> impl Future<Output = Result<TokenResponse<'_>, flow::Error>> + Send;
 }
 
 #[instrument(skip_all)]
@@ -24,7 +24,7 @@ pub async fn perform<CE, I>(
     req: http::Request<Bytes>,
     client_extractor: CE,
     token_issuer: I,
-) -> Result<http::Response<Bytes>, FlowError>
+) -> Result<http::Response<Bytes>, flow::Error>
 where
     CE: ClientExtractor,
     I: Issuer,
@@ -44,7 +44,7 @@ where
 
     if *grant_type != "authorization_code" {
         error!(?client_id, "grant_type is not authorization_code");
-        return Err(FlowError::UnsupportedGrantType);
+        return Err(flow::Error::UnsupportedGrantType);
     }
 
     let client = client_extractor
@@ -53,16 +53,16 @@ where
 
     if client.redirect_uri != *redirect_uri {
         error!(?client_id, "redirect uri doesn't match");
-        return Err(FlowError::InvalidClient);
+        return Err(flow::Error::InvalidClient);
     }
 
     let Some(authorization) = token_issuer.load_authorization(code).await? else {
-        return Err(FlowError::InvalidGrant);
+        return Err(flow::Error::InvalidGrant);
     };
 
     // This check is constant time :3
     if client != authorization.client {
-        return Err(FlowError::UnauthorizedClient);
+        return Err(flow::Error::UnauthorizedClient);
     }
 
     if let Some(ref pkce) = authorization.pkce_payload {
diff --git a/lib/komainu/src/flow/mod.rs b/lib/komainu/src/flow/mod.rs
index a5f10721b..6e817f2a5 100644
--- a/lib/komainu/src/flow/mod.rs
+++ b/lib/komainu/src/flow/mod.rs
@@ -8,20 +8,20 @@ pub mod pkce;
 pub mod refresh;
 
 trait OptionExt<T> {
-    fn or_invalid_request(self) -> Result<T, FlowError>;
+    fn or_invalid_request(self) -> Result<T, Error>;
 }
 
 impl<T> OptionExt<T> for Option<T> {
     #[inline]
-    fn or_invalid_request(self) -> Result<T, FlowError> {
-        self.ok_or(FlowError::InvalidRequest)
+    fn or_invalid_request(self) -> Result<T, Error> {
+        self.ok_or(Error::InvalidRequest)
     }
 }
 
 #[derive(Debug, Display, Error, Serialize)]
 #[serde(rename_all = "snake_case")]
 #[strum(serialize_all = "snake_case")]
-pub enum FlowError {
+pub enum Error {
     InvalidRequest,
     InvalidClient,
     InvalidGrant,
@@ -49,6 +49,6 @@ pub enum TokenResponse<'a> {
         expires_in: u64,
     },
     Error {
-        errorr: FlowError,
+        errorr: Error,
     },
 }
diff --git a/lib/komainu/src/flow/pkce.rs b/lib/komainu/src/flow/pkce.rs
index ab18441cc..fc3075b93 100644
--- a/lib/komainu/src/flow/pkce.rs
+++ b/lib/komainu/src/flow/pkce.rs
@@ -1,4 +1,4 @@
-use crate::{error::Error, flow::FlowError};
+use crate::{error::Error, flow};
 use serde::{Deserialize, Serialize};
 use sha2::{Digest, Sha256};
 use std::borrow::Cow;
@@ -22,7 +22,7 @@ pub struct Payload<'a> {
 
 impl Payload<'_> {
     #[inline]
-    fn verify_s256(&self, code_verifier: &str) -> Result<(), FlowError> {
+    fn verify_s256(&self, code_verifier: &str) -> Result<(), flow::Error> {
         let decoded = base64_simd::URL_SAFE_NO_PAD
             .decode_to_vec(self.challenge.as_bytes())
             .inspect_err(|error| debug!(?error, "failed to decode pkce payload"))
@@ -32,22 +32,22 @@ impl Payload<'_> {
         if decoded.ct_eq(hash.as_slice()).into() {
             Ok(())
         } else {
-            Err(FlowError::InvalidGrant)
+            Err(flow::Error::InvalidGrant)
         }
     }
 
     #[inline]
-    fn verify_none(&self, code_verifier: &str) -> Result<(), FlowError> {
+    fn verify_none(&self, code_verifier: &str) -> Result<(), flow::Error> {
         let challenge_bytes = self.challenge.as_bytes();
         if challenge_bytes.ct_eq(code_verifier.as_bytes()).into() {
             Ok(())
         } else {
-            Err(FlowError::InvalidGrant)
+            Err(flow::Error::InvalidGrant)
         }
     }
 
     #[inline]
-    pub fn verify(&self, code_verifier: &str) -> Result<(), FlowError> {
+    pub fn verify(&self, code_verifier: &str) -> Result<(), flow::Error> {
         match self.method {
             Method::None => self.verify_none(code_verifier),
             Method::S256 => self.verify_s256(code_verifier),
diff --git a/lib/komainu/src/flow/refresh.rs b/lib/komainu/src/flow/refresh.rs
index 74c580bb8..658b450c1 100644
--- a/lib/komainu/src/flow/refresh.rs
+++ b/lib/komainu/src/flow/refresh.rs
@@ -1,6 +1,6 @@
 use crate::{
     extract::ClientCredentials,
-    flow::{FlowError, OptionExt, TokenResponse},
+    flow::{self, OptionExt, TokenResponse},
     params::ParamStorage,
     Client, ClientExtractor,
 };
@@ -12,7 +12,7 @@ pub trait Issuer {
         &self,
         client: &Client<'_>,
         refresh_token: &str,
-    ) -> impl Future<Output = Result<TokenResponse<'_>, FlowError>> + Send;
+    ) -> impl Future<Output = Result<TokenResponse<'_>, flow::Error>> + Send;
 }
 
 #[instrument(skip_all)]
@@ -20,7 +20,7 @@ pub async fn perform<CE, I>(
     req: http::Request<Bytes>,
     client_extractor: CE,
     token_issuer: I,
-) -> Result<http::Response<Bytes>, FlowError>
+) -> Result<http::Response<Bytes>, flow::Error>
 where
     CE: ClientExtractor,
     I: Issuer,
@@ -39,7 +39,7 @@ where
 
     if *grant_type != "refresh_token" {
         debug!(?client_id, "grant_type is not refresh_token");
-        return Err(FlowError::UnsupportedGrantType);
+        return Err(flow::Error::UnsupportedGrantType);
     }
 
     let client = client_extractor