diff --git a/crates/service/web/storyteller_web/src/api_doc_cli.rs b/crates/service/web/storyteller_web/src/api_doc_cli.rs
index fc62536c7c..3d6aebd27e 100644
--- a/crates/service/web/storyteller_web/src/api_doc_cli.rs
+++ b/crates/service/web/storyteller_web/src/api_doc_cli.rs
@@ -27,6 +27,7 @@ use errors::AnyhowResult;
 
 pub mod billing;
 pub mod configs;
+pub mod error;
 pub mod http_server;
 pub mod state;
 pub mod threads;
diff --git a/crates/service/web/storyteller_web/src/api_doc_server.rs b/crates/service/web/storyteller_web/src/api_doc_server.rs
index 1924c42725..de5c546b18 100644
--- a/crates/service/web/storyteller_web/src/api_doc_server.rs
+++ b/crates/service/web/storyteller_web/src/api_doc_server.rs
@@ -30,6 +30,7 @@ use crate::configs::static_api_tokens::StaticApiTokenSet;
 
 pub mod billing;
 pub mod configs;
+pub mod error;
 pub mod http_server;
 pub mod state;
 pub mod threads;
diff --git a/crates/service/web/storyteller_web/src/error/internal_error.rs b/crates/service/web/storyteller_web/src/error/internal_error.rs
new file mode 100644
index 0000000000..0c479310bd
--- /dev/null
+++ b/crates/service/web/storyteller_web/src/error/internal_error.rs
@@ -0,0 +1,37 @@
+use std::error::Error;
+use std::fmt::{Debug, Display, Formatter};
+
+/// Any generic errors arising internally.
+/// An error class that we do not expose via the API.
+/// This should be massaged before we send it to the user.
+#[derive(Debug)]
+pub enum InternalError {
+  /// Issue with HMAC decoding
+  /// This is typically when using development cookies against production,
+  /// or vice versa.
+  VisitorCookieError(String),
+  
+  /// Decode error with AVT cookie missing a required field.
+  VisitorCookieMissingField(&'static str),
+
+  /// Catch instances of anyhow::Error.
+  AnyhowError(anyhow::Error),
+}
+
+impl Error for InternalError {}
+
+impl Display for InternalError {
+  fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
+    match self {
+      InternalError::VisitorCookieError(reason) => write!(f, "Visitor cookie error: {:?}", reason),
+      InternalError::VisitorCookieMissingField(field) => write!(f, "Visitor cookie missing field: {}", field),
+      InternalError::AnyhowError(err) => write!(f, "Anyhow error: {}", err),
+    }
+  }
+}
+
+impl From<anyhow::Error> for InternalError {
+  fn from(err: anyhow::Error) -> Self {
+    InternalError::AnyhowError(err)
+  }
+}
diff --git a/crates/service/web/storyteller_web/src/error/mod.rs b/crates/service/web/storyteller_web/src/error/mod.rs
new file mode 100644
index 0000000000..3e6d672990
--- /dev/null
+++ b/crates/service/web/storyteller_web/src/error/mod.rs
@@ -0,0 +1 @@
+pub mod internal_error;
\ No newline at end of file
diff --git a/crates/service/web/storyteller_web/src/http_server/cookies/anonymous_visitor_tracking/avt_cookie_manager.rs b/crates/service/web/storyteller_web/src/http_server/cookies/anonymous_visitor_tracking/avt_cookie_manager.rs
index c5a009796e..93b1f906a2 100644
--- a/crates/service/web/storyteller_web/src/http_server/cookies/anonymous_visitor_tracking/avt_cookie_manager.rs
+++ b/crates/service/web/storyteller_web/src/http_server/cookies/anonymous_visitor_tracking/avt_cookie_manager.rs
@@ -4,12 +4,12 @@ use actix_web::HttpRequest;
 use anyhow::anyhow;
 use log::warn;
 
+use crate::error::internal_error::InternalError;
+use crate::http_server::cookies::anonymous_visitor_tracking::avt_cookie_payload::AvtCookiePayload;
 use cookies::jwt_signer::JwtSigner;
 use errors::AnyhowResult;
 use tokens::tokens::anonymous_visitor_tracking::AnonymousVisitorTrackingToken;
 
-use crate::http_server::cookies::anonymous_visitor_tracking::avt_cookie_payload::AvtCookiePayload;
-
 const VISITOR_COOKIE_NAME : &str = "visitor";
 
 /// Handle "anonymous visitor tracking" cookies.
@@ -70,7 +70,7 @@ impl AvtCookieManager {
     Ok(payload)
   }
 
-  pub fn decode_cookie_payload_from_request(&self, request: &HttpRequest) -> AnyhowResult<Option<AvtCookiePayload>> {
+  pub fn decode_cookie_payload_from_request(&self, request: &HttpRequest) -> Result<Option<AvtCookiePayload>, InternalError> {
     let cookie = match request.cookie(VISITOR_COOKIE_NAME) {
       None => return Ok(None),
       Some(cookie) => cookie,
@@ -79,7 +79,7 @@ impl AvtCookieManager {
     match self.decode_cookie_payload(&cookie) {
       Err(e) => {
         warn!("Visitor cookie decode error: {:?}", e);
-        Err(anyhow!("Could not decode visitor cookie: {:?}", e))
+        Err(InternalError::VisitorCookieError(e.to_string()))
       },
       Ok(payload) => Ok(Some(payload)),
     }
diff --git a/crates/service/web/storyteller_web/src/http_server/cookies/anonymous_visitor_tracking/avt_cookie_payload.rs b/crates/service/web/storyteller_web/src/http_server/cookies/anonymous_visitor_tracking/avt_cookie_payload.rs
index 49d19c1f6d..0706d90590 100644
--- a/crates/service/web/storyteller_web/src/http_server/cookies/anonymous_visitor_tracking/avt_cookie_payload.rs
+++ b/crates/service/web/storyteller_web/src/http_server/cookies/anonymous_visitor_tracking/avt_cookie_payload.rs
@@ -1,9 +1,7 @@
 use std::collections::BTreeMap;
 use std::str::FromStr;
 
-use anyhow::anyhow;
-
-use errors::AnyhowResult;
+use crate::error::internal_error::InternalError;
 use tokens::tokens::anonymous_visitor_tracking::AnonymousVisitorTrackingToken;
 
 /**
@@ -38,18 +36,19 @@ impl AvtCookiePayload {
     }
   }
 
-  pub fn from_map(map: BTreeMap<String, String>) -> AnyhowResult<Self> {
+  pub fn from_map(map: BTreeMap<String, String>) -> Result<Self, InternalError> {
     let avt_token = map.get("avt_token")
-        .ok_or(anyhow!("avt_token not present"))?
-        .to_string();
+        .ok_or_else(|| InternalError::VisitorCookieMissingField("avt_token"))?;
 
     let cookie_version = map
         .get("cookie_version")
-        .ok_or(anyhow!("avt_token not present"))?;
+        .ok_or_else(|| InternalError::VisitorCookieMissingField("cookie_version"))?;
 
-    let avt_token = AnonymousVisitorTrackingToken::new_from_str(&avt_token);
+    let avt_token = AnonymousVisitorTrackingToken::new_from_str(avt_token);
 
-    let cookie_version = u32::from_str(cookie_version)?;
+    let cookie_version = u32::from_str(cookie_version)
+        .map_err(|e| InternalError::VisitorCookieError(
+          format!("invalid integer for cookie_version: {:?}, version: {}", e, cookie_version)))?;
 
     Ok(AvtCookiePayload {
       avt_token,
diff --git a/crates/service/web/storyteller_web/src/main.rs b/crates/service/web/storyteller_web/src/main.rs
index bc12ed599d..73a9a72dc6 100644
--- a/crates/service/web/storyteller_web/src/main.rs
+++ b/crates/service/web/storyteller_web/src/main.rs
@@ -92,6 +92,7 @@ use crate::util::troll_user_bans::troll_user_ban_list::TrollUserBanList;
 
 pub mod billing;
 pub mod configs;
+pub mod error;
 pub mod http_server;
 pub mod state;
 pub mod threads;