diff --git a/openfut-utas-host/src/lib.rs b/openfut-utas-host/src/lib.rs
index 877a070..abbb03d 100644
--- a/openfut-utas-host/src/lib.rs
+++ b/openfut-utas-host/src/lib.rs
@@ -350,6 +350,171 @@ impl CoreAccess for HttpCoreClient {
     }
 }
 
+// ───────────────────────────── Core economy boundary ────────────────────────
+
+/// One unconsumed entitlement Core reports for the active club.
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct EconomyEntitlement {
+    pub id: String,
+    pub definition_id: String,
+}
+
+/// Outcome of a purchase: post-debit balance + the new entitlement id.
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct EconomyPurchase {
+    pub balance: i64,
+    pub entitlement_id: String,
+}
+
+/// An item to place into inventory on entitlement redemption. `item_id` is the
+/// caller-minted opaque Core instance id (the adapter maps it to/from the FIFA
+/// numeric wire id via the identity store); `card_id` is the definition ref.
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct EconomyGrantItem {
+    pub item_id: String,
+    pub card_id: String,
+}
+
+/// The host's authoritative economy transport to Core. Every method is a single
+/// durable Core transaction. **Fail-closed:** on any transport/status/parse
+/// error the caller MUST surface a controlled error and NEVER fall back to
+/// Python — a Python fallback would reintroduce a second writer.
+pub trait CoreEconomy: Send + Sync {
+    fn balance(&self) -> Result<i64, CoreError>;
+    fn entitlements(&self) -> Result<Vec<EconomyEntitlement>, CoreError>;
+    fn purchase_entitlement(
+        &self,
+        cost: i64,
+        definition_id: &str,
+    ) -> Result<EconomyPurchase, CoreError>;
+    fn redeem_entitlement(
+        &self,
+        entitlement_id: &str,
+        items: &[EconomyGrantItem],
+    ) -> Result<String, CoreError>;
+    fn sell_item(&self, item_id: &str, price: i64) -> Result<i64, CoreError>;
+    fn grant_reward(&self, amount: i64) -> Result<i64, CoreError>;
+    fn purchase_item(&self, cost: i64, item_id: &str, card_id: &str) -> Result<i64, CoreError>;
+}
+
+impl HttpCoreClient {
+    fn economy_url(&self, tail: &str) -> String {
+        format!("{}/economy/{}", self.base_url, tail)
+    }
+
+    fn economy_get(&self, tail: &str) -> Result<Value, CoreError> {
+        let resp = self
+            .client
+            .get(self.economy_url(tail))
+            .header("X-OpenFUT-Game", &self.game)
+            .send()
+            .map_err(|e| CoreError::Http(e.to_string()))?;
+        let status = resp.status().as_u16();
+        if !(200..300).contains(&status) {
+            return Err(CoreError::Status(status));
+        }
+        resp.json().map_err(|e| CoreError::Parse(e.to_string()))
+    }
+
+    fn economy_post(&self, tail: &str, body: &Value) -> Result<Value, CoreError> {
+        let resp = self
+            .client
+            .post(self.economy_url(tail))
+            .header("X-OpenFUT-Game", &self.game)
+            .json(body)
+            .send()
+            .map_err(|e| CoreError::Http(e.to_string()))?;
+        let status = resp.status().as_u16();
+        if !(200..300).contains(&status) {
+            return Err(CoreError::Status(status));
+        }
+        resp.json().map_err(|e| CoreError::Parse(e.to_string()))
+    }
+}
+
+fn json_i64(v: &Value, key: &str) -> Result<i64, CoreError> {
+    v.get(key)
+        .and_then(Value::as_i64)
+        .ok_or_else(|| CoreError::Parse(format!("missing i64 field `{key}`")))
+}
+
+fn json_str(v: &Value, key: &str) -> Result<String, CoreError> {
+    v.get(key)
+        .and_then(Value::as_str)
+        .map(str::to_string)
+        .ok_or_else(|| CoreError::Parse(format!("missing string field `{key}`")))
+}
+
+impl CoreEconomy for HttpCoreClient {
+    fn balance(&self) -> Result<i64, CoreError> {
+        json_i64(&self.economy_get("balance")?, "balance")
+    }
+
+    fn entitlements(&self) -> Result<Vec<EconomyEntitlement>, CoreError> {
+        let v = self.economy_get("entitlements")?;
+        let arr = v
+            .as_array()
+            .ok_or_else(|| CoreError::Parse("entitlements not an array".into()))?;
+        arr.iter()
+            .map(|e| {
+                Ok(EconomyEntitlement {
+                    id: json_str(e, "id")?,
+                    definition_id: json_str(e, "definition_id")?,
+                })
+            })
+            .collect()
+    }
+
+    fn purchase_entitlement(
+        &self,
+        cost: i64,
+        definition_id: &str,
+    ) -> Result<EconomyPurchase, CoreError> {
+        let v = self.economy_post(
+            "purchase-entitlement",
+            &json!({ "cost": cost, "definition_id": definition_id }),
+        )?;
+        Ok(EconomyPurchase {
+            balance: json_i64(&v, "balance")?,
+            entitlement_id: json_str(&v, "entitlement_id")?,
+        })
+    }
+
+    fn redeem_entitlement(
+        &self,
+        entitlement_id: &str,
+        items: &[EconomyGrantItem],
+    ) -> Result<String, CoreError> {
+        let items_json: Vec<Value> = items
+            .iter()
+            .map(|i| json!({ "item_id": i.item_id, "card_id": i.card_id }))
+            .collect();
+        let v = self.economy_post(
+            "redeem-entitlement",
+            &json!({ "entitlement_id": entitlement_id, "items": items_json }),
+        )?;
+        json_str(&v, "definition_id")
+    }
+
+    fn sell_item(&self, item_id: &str, price: i64) -> Result<i64, CoreError> {
+        let v = self.economy_post("sell-item", &json!({ "item_id": item_id, "price": price }))?;
+        json_i64(&v, "balance")
+    }
+
+    fn grant_reward(&self, amount: i64) -> Result<i64, CoreError> {
+        let v = self.economy_post("grant-reward", &json!({ "amount": amount }))?;
+        json_i64(&v, "balance")
+    }
+
+    fn purchase_item(&self, cost: i64, item_id: &str, card_id: &str) -> Result<i64, CoreError> {
+        let v = self.economy_post(
+            "purchase-item",
+            &json!({ "cost": cost, "item_id": item_id, "card_id": card_id }),
+        )?;
+        json_i64(&v, "balance")
+    }
+}
+
 /// Serialize a [`CoreReplaceRequest`] into the `PUT /squad/replace` JSON body.
 pub fn replace_request_body(req: &CoreReplaceRequest) -> Value {
     let slots: Vec<Value> = req
@@ -1185,6 +1350,46 @@ pub fn handle_user_mass_info(
     (resp, log)
 }
 
+// ─────────────── Rust economy handlers (Core-backed authority) ───────────────
+//
+// These implement the FIFA17 economy routes against Core economy authority.
+// They are Core-backed and fail-closed: a Core error yields a controlled FIFA-
+// compatible response and NEVER a Python fallback (which would be a second
+// writer). They are wired into `classify` only as one coherent barrier once the
+// whole coins cluster (writers + readers) flips together and Core is seeded from
+// the profile — a partial flip would desync the client's coin counter.
+
+/// Build the `GET /user/credits` body — byte-shape-identical to the Python
+/// oracle (`credits` + `currencies[].funds/finalFunds`, optional
+/// `unopenedPacks.recoveredPacks`). The hub coin counter binds to
+/// `currencies[0].funds`, not `credits`.
+pub fn build_credits_body(coins: i64, unopened_count: usize) -> Value {
+    let mut body = json!({
+        "credits": coins,
+        "currencies": [
+            {"name": "coins", "funds": coins, "finalFunds": coins},
+            {"name": "points", "funds": 0, "finalFunds": 0},
+        ],
+    });
+    if unopened_count > 0 {
+        body.as_object_mut().unwrap().insert(
+            "unopenedPacks".into(),
+            json!({ "preOrderPacks": 0, "recoveredPacks": unopened_count }),
+        );
+    }
+    body
+}
+
+/// `GET /user/credits` from Core authority: coins = Core balance, recoveredPacks
+/// = Core unconsumed entitlement count. Fail-closed on any Core error (503, no
+/// Python fallback, no fabricated balance).
+pub fn handle_credits(econ: &dyn CoreEconomy) -> WireResponse {
+    match (econ.balance(), econ.entitlements()) {
+        (Ok(coins), Ok(ents)) => json_response(&build_credits_body(coins, ents.len())),
+        _ => error_response(503, "core_unavailable"),
+    }
+}
+
 // ───────────────────────────── HTTP wire types ──────────────────────────────
 
 /// A response ready to write: status, headers, body.
@@ -1816,6 +2021,115 @@ fn write_response<W: Write>(w: &mut W, resp: &WireResponse) -> std::io::Result<(
 mod tests {
     use super::*;
 
+    /// A configurable in-memory economy double: real balance/entitlements, or a
+    /// forced error to prove fail-closed behavior.
+    struct FakeEconomy {
+        balance: i64,
+        entitlements: Vec<EconomyEntitlement>,
+        fail: bool,
+    }
+    impl FakeEconomy {
+        fn ok(balance: i64, ents: usize) -> Self {
+            FakeEconomy {
+                balance,
+                entitlements: (0..ents)
+                    .map(|i| EconomyEntitlement {
+                        id: format!("e{i}"),
+                        definition_id: "pack".into(),
+                    })
+                    .collect(),
+                fail: false,
+            }
+        }
+        fn failing() -> Self {
+            FakeEconomy {
+                balance: 0,
+                entitlements: vec![],
+                fail: true,
+            }
+        }
+    }
+    impl CoreEconomy for FakeEconomy {
+        fn balance(&self) -> Result<i64, CoreError> {
+            if self.fail {
+                Err(CoreError::Status(500))
+            } else {
+                Ok(self.balance)
+            }
+        }
+        fn entitlements(&self) -> Result<Vec<EconomyEntitlement>, CoreError> {
+            if self.fail {
+                Err(CoreError::Status(500))
+            } else {
+                Ok(self.entitlements.clone())
+            }
+        }
+        fn purchase_entitlement(
+            &self,
+            _cost: i64,
+            definition_id: &str,
+        ) -> Result<EconomyPurchase, CoreError> {
+            Ok(EconomyPurchase {
+                balance: self.balance,
+                entitlement_id: format!("bought:{definition_id}"),
+            })
+        }
+        fn redeem_entitlement(
+            &self,
+            _entitlement_id: &str,
+            _items: &[EconomyGrantItem],
+        ) -> Result<String, CoreError> {
+            Ok("pack".into())
+        }
+        fn sell_item(&self, _item_id: &str, _price: i64) -> Result<i64, CoreError> {
+            Ok(self.balance)
+        }
+        fn grant_reward(&self, _amount: i64) -> Result<i64, CoreError> {
+            Ok(self.balance)
+        }
+        fn purchase_item(
+            &self,
+            _cost: i64,
+            _item_id: &str,
+            _card_id: &str,
+        ) -> Result<i64, CoreError> {
+            Ok(self.balance)
+        }
+    }
+
+    #[test]
+    fn credits_body_matches_oracle_shape() {
+        let b = build_credits_body(29_876_776, 0);
+        assert_eq!(b["credits"], 29_876_776);
+        assert_eq!(b["currencies"][0]["name"], "coins");
+        assert_eq!(b["currencies"][0]["funds"], 29_876_776);
+        assert_eq!(b["currencies"][0]["finalFunds"], 29_876_776);
+        assert_eq!(b["currencies"][1]["name"], "points");
+        assert_eq!(b["currencies"][1]["funds"], 0);
+        // No packs -> no unopenedPacks key (keeps the badge off).
+        assert!(b.get("unopenedPacks").is_none());
+        let b2 = build_credits_body(100, 3);
+        assert_eq!(b2["unopenedPacks"]["recoveredPacks"], 3);
+        assert_eq!(b2["unopenedPacks"]["preOrderPacks"], 0);
+    }
+
+    #[test]
+    fn handle_credits_reads_core_authority() {
+        let econ = FakeEconomy::ok(4600, 2);
+        let resp = handle_credits(&econ);
+        assert_eq!(resp.status, 200);
+        let body: Value = serde_json::from_slice(&resp.body).unwrap();
+        assert_eq!(body["currencies"][0]["funds"], 4600);
+        assert_eq!(body["unopenedPacks"]["recoveredPacks"], 2);
+    }
+
+    #[test]
+    fn handle_credits_fails_closed_on_core_error() {
+        // Core error -> controlled 503, NEVER a Python fallback or fabricated balance.
+        let resp = handle_credits(&FakeEconomy::failing());
+        assert_eq!(resp.status, 503);
+    }
+
     #[test]
     fn special_filter_keeps_only_specials_and_paginates_filtered_set() {
         let mk = |id: i64, rf: i64| serde_json::json!({ "id": id, "rareflag": rf });