diff --git a/Cargo.lock b/Cargo.lock
index c341cf0..323de25 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -192,6 +192,28 @@ dependencies = [
  "tower-service",
 ]
 
+[[package]]
+name = "axum-extra"
+version = "0.9.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "523ae92256049a3b02d3bb4df80152386cd97ddba0c8c5077619bdc8c4b1859b"
+dependencies = [
+ "axum 0.7.2",
+ "axum-core 0.4.1",
+ "bytes",
+ "futures-util",
+ "headers 0.4.0",
+ "http 1.0.0",
+ "http-body 1.0.0",
+ "http-body-util",
+ "mime",
+ "pin-project-lite",
+ "serde",
+ "tower",
+ "tower-layer",
+ "tower-service",
+]
+
 [[package]]
 name = "backtrace"
 version = "0.3.69"
@@ -260,6 +282,8 @@ name = "cch23-8bit"
 version = "0.1.0"
 dependencies = [
  "axum 0.7.2",
+ "axum-extra",
+ "base64",
  "serde",
  "serde_json",
  "shuttle-axum",
@@ -620,13 +644,28 @@ checksum = "06683b93020a07e3dbcf5f8c0f6d40080d725bea7936fc01ad345c01b97dc270"
 dependencies = [
  "base64",
  "bytes",
- "headers-core",
+ "headers-core 0.2.0",
  "http 0.2.11",
  "httpdate",
  "mime",
  "sha1",
 ]
 
+[[package]]
+name = "headers"
+version = "0.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "322106e6bd0cba2d5ead589ddb8150a13d7c4217cf80d7c4f682ca994ccc6aa9"
+dependencies = [
+ "base64",
+ "bytes",
+ "headers-core 0.3.0",
+ "http 1.0.0",
+ "httpdate",
+ "mime",
+ "sha1",
+]
+
 [[package]]
 name = "headers-core"
 version = "0.2.0"
@@ -636,6 +675,15 @@ dependencies = [
  "http 0.2.11",
 ]
 
+[[package]]
+name = "headers-core"
+version = "0.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "54b4a22553d4242c49fddb9ba998a99962b5cc6f22cb5a3482bec22522403ce4"
+dependencies = [
+ "http 1.0.0",
+]
+
 [[package]]
 name = "heck"
 version = "0.4.1"
@@ -1636,7 +1684,7 @@ dependencies = [
  "chrono",
  "comfy-table",
  "crossterm 0.27.0",
- "headers",
+ "headers 0.3.9",
  "http 0.2.11",
  "http-body 0.4.5",
  "hyper 0.14.27",
diff --git a/Cargo.toml b/Cargo.toml
index 8b668ba..ca42180 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -5,6 +5,8 @@ edition = "2021"
 
 [dependencies]
 axum = "0.7.2"
+axum-extra = { version = "0.9.0", features = ["typed-header"] }
+base64 = "0.21.5"
 serde = { version = "1.0.193", features = ["derive"] }
 serde_json = "1.0.108"
 shuttle-axum = { version = "0.35.0", default-features = false, features = ["axum-0-7"] }
diff --git a/src/cal/day01.rs b/src/cal/day01.rs
index 2af1e5b..ed8ee25 100644
--- a/src/cal/day01.rs
+++ b/src/cal/day01.rs
@@ -7,7 +7,7 @@ pub(crate) fn router() -> Router {
 async fn cube_bits(Path(ids): Path<String>) -> Result<impl IntoResponse, StatusCode> {
     let res = ids
         .split('/')
-        .map(|id| id.parse::<i32>())
+        .map(str::parse::<i32>)
         .collect::<Result<Vec<_>, _>>()
         .map_err(|_| StatusCode::BAD_REQUEST)?
         .into_iter()
diff --git a/src/cal/day07.rs b/src/cal/day07.rs
new file mode 100644
index 0000000..2b76c54
--- /dev/null
+++ b/src/cal/day07.rs
@@ -0,0 +1,62 @@
+use axum::{http::StatusCode, response::IntoResponse, routing::get, Json, Router};
+use axum_extra::{headers::Cookie, TypedHeader};
+use base64::{engine::general_purpose, Engine as _};
+use std::collections::HashMap;
+
+pub(crate) fn router() -> Router {
+    Router::new()
+        .route("/7/decode", get(decode))
+        .route("/7/bake", get(bake))
+}
+
+async fn decode(
+    TypedHeader(cookie): TypedHeader<Cookie>,
+) -> Result<impl IntoResponse, (StatusCode, String)> {
+    let recipe = cookie
+        .get("recipe")
+        .ok_or((StatusCode::BAD_REQUEST, "recipe cookie missing".to_string()))?;
+    let decoded = general_purpose::STANDARD
+        .decode(recipe)
+        .map_err(|e| (StatusCode::BAD_REQUEST, format!("{e:?}")))?;
+    let json =
+        String::from_utf8(decoded).map_err(|e| (StatusCode::BAD_REQUEST, format!("{e:?}")))?;
+    Ok(json)
+}
+
+#[derive(serde::Deserialize)]
+struct Bake {
+    recipe: HashMap<String, i32>,
+    pantry: HashMap<String, i32>,
+}
+
+#[derive(serde::Serialize)]
+struct Cookies {
+    cookies: i32,
+    pantry: HashMap<String, i32>,
+}
+
+async fn bake(
+    TypedHeader(cookie): TypedHeader<Cookie>,
+) -> Result<Json<Cookies>, (StatusCode, String)> {
+    let recipe = cookie
+        .get("recipe")
+        .ok_or((StatusCode::BAD_REQUEST, "recipe cookie missing".to_string()))?;
+    let decoded = general_purpose::STANDARD
+        .decode(recipe)
+        .map_err(|e| (StatusCode::BAD_REQUEST, format!("{e:?}")))?;
+    let Bake { recipe, mut pantry } = serde_json::from_slice(&decoded)
+        .map_err(|e| (StatusCode::BAD_REQUEST, format!("{e:?}")))?;
+    if let Some(cookies) = recipe
+        .iter()
+        .map(|(i, a)| pantry.get(i).map(|p| p / a))
+        .collect::<Option<Vec<_>>>()
+        .and_then(|v| v.into_iter().min())
+    {
+        for (i, a) in recipe {
+            *pantry.get_mut(&i).unwrap() -= a * cookies;
+        }
+        Ok(Json(Cookies { cookies, pantry }))
+    } else {
+        Ok(Json(Cookies { cookies: 0, pantry }))
+    }
+}
diff --git a/src/cal/mod.rs b/src/cal/mod.rs
index b302856..094f8e6 100644
--- a/src/cal/mod.rs
+++ b/src/cal/mod.rs
@@ -2,6 +2,7 @@ mod day00;
 mod day01;
 mod day04;
 mod day06;
+mod day07;
 
 pub(crate) fn router() -> axum::Router {
     axum::Router::new()
@@ -9,4 +10,5 @@ pub(crate) fn router() -> axum::Router {
         .nest("/", day01::router())
         .nest("/", day04::router())
         .nest("/", day06::router())
+        .nest("/", day07::router())
 }