diff --git a/web/src/handlers/did.rs b/web/src/handlers/did.rs
new file mode 100644
index 0000000..cca8154
--- /dev/null
+++ b/web/src/handlers/did.rs
@@ -0,0 +1,27 @@
+use axum::Json;
+use axum::response::IntoResponse;
+use serde_json::json;
+use std::env;
+
+pub async fn did_json_handler() -> impl IntoResponse {
+    let oauth_host = env::var("OAUTH_HOST").unwrap_or_else(|_| "localhost".to_string());
+    let did = format!("did:web:{oauth_host}");
+    let service_endpoint = format!("https://{oauth_host}");
+
+    Json(json!({
+        "@context": [
+            "https://www.w3.org/ns/did/v1",
+            "https://w3id.org/security/multikey/v1"
+        ],
+        "id": did,
+        "alsoKnownAs": [],
+        "service": [
+            {
+                "id": "#advent",
+                "type": "AdventChallengeService",
+                "serviceEndpoint": service_endpoint
+            }
+        ],
+        "verificationMethod": []
+    }))
+}
diff --git a/web/src/handlers/mod.rs b/web/src/handlers/mod.rs
index d01304d..865bbba 100644
--- a/web/src/handlers/mod.rs
+++ b/web/src/handlers/mod.rs
@@ -1,4 +1,5 @@
 pub mod auth;
 pub mod day;
+pub mod did;
 pub mod leaderboard;
 pub mod oauth_metadata;
diff --git a/web/src/main.rs b/web/src/main.rs
index adaf80b..5e43ce4 100644
--- a/web/src/main.rs
+++ b/web/src/main.rs
@@ -307,10 +307,15 @@ async fn main() -> Result<(), Box<dyn std::error::Error>> {
         .nest_service("/public", axum_embed::ServeEmbed::<Assets>::new());
 
     if env::var("OAUTH_HOST").is_ok() {
-        app = app.route(
-            "/oauth-client-metadata.json",
-            get(handlers::oauth_metadata::oauth_client_metadata_handler),
-        );
+        app = app
+            .route(
+                "/oauth-client-metadata.json",
+                get(handlers::oauth_metadata::oauth_client_metadata_handler),
+            )
+            .route(
+                "/.well-known/did.json",
+                get(handlers::did::did_json_handler),
+            );
     }
 
     let app = app