diff --git a/.changeset/seven-hornets-shout.md b/.changeset/seven-hornets-shout.md
new file mode 100644
index 0000000..2fc0fb2
--- /dev/null
+++ b/.changeset/seven-hornets-shout.md
@@ -0,0 +1,5 @@
+---
+"@oaknetwork/api": minor
+---
+
+added sync and balance API
diff --git a/packages/api/__tests__/unit/services.test.ts b/packages/api/__tests__/unit/services.test.ts
index 261e167..99f6415 100644
--- a/packages/api/__tests__/unit/services.test.ts
+++ b/packages/api/__tests__/unit/services.test.ts
@@ -200,6 +200,27 @@ describe("Crowdsplit services (Unit)", () => {
         authConfig,
       ],
     });
+    await expectSuccess({
+      client,
+      call: () =>
+        service.sync("cust-1", { providers: ["stripe"], fields: ["shipping"] }),
+      httpMethod: "post",
+      expectedArgs: [
+        `${SANDBOX_URL}/api/v1/customers/cust-1/sync`,
+        { providers: ["stripe"], fields: ["shipping"] },
+        authConfig,
+      ],
+    });
+    await expectSuccess({
+      client,
+      call: () =>
+        service.balance("cust-1", { provider: "stripe", role: "customer" }),
+      httpMethod: "get",
+      expectedArgs: [
+        `${SANDBOX_URL}/api/v1/customers/cust-1/balance?provider=stripe&role=customer`,
+        authConfig,
+      ],
+    });
     await expectFailure({
       call: () => service.update("cust-1", { email: "new@example.com" }),
       httpMethod: "put",
@@ -216,6 +237,18 @@ describe("Crowdsplit services (Unit)", () => {
     await expectTokenFailure(() =>
       tokenErrorService.update("cust-1", { email: "t@t.com" }),
     );
+    await expectTokenFailure(() =>
+      tokenErrorService.sync("cust-1", {
+        providers: ["stripe"],
+        fields: ["shipping"],
+      }),
+    );
+    await expectTokenFailure(() =>
+      tokenErrorService.balance("cust-1", {
+        provider: "stripe",
+        role: "customer",
+      }),
+    );
   });
 
   it("payment service methods", async () => {
diff --git a/packages/api/src/services/customerService.ts b/packages/api/src/services/customerService.ts
index 4a0f71d..a549408 100644
--- a/packages/api/src/services/customerService.ts
+++ b/packages/api/src/services/customerService.ts
@@ -13,6 +13,13 @@ export interface CustomerService {
     id: string,
     customer: Customer.Request,
   ): Promise<Result<Customer.Response>>;
+
+  sync(id: string, sync: Customer.Sync): Promise<Result<Customer.SyncResponse>>;
+
+  balance(
+    customer_id: string,
+    filter: Customer.BalanceFilter,
+  ): Promise<Result<Customer.BalanceResponse>>;
 }
 
 export const createCustomerService = (client: OakClient): CustomerService => ({
@@ -91,4 +98,47 @@ export const createCustomerService = (client: OakClient): CustomerService => ({
       },
     );
   },
+
+  async sync(
+    id: string,
+    sync: Customer.Sync,
+  ): Promise<Result<Customer.SyncResponse>> {
+    const token = await client.getAccessToken();
+    if (!token.ok) {
+      return err(token.error);
+    }
+
+    return httpClient.post<Customer.SyncResponse>(
+      `${client.config.baseUrl}/api/v1/customers/${id}/sync`,
+      sync,
+      {
+        headers: {
+          Authorization: `Bearer ${token.value}`,
+        },
+        retryOptions: client.retryOptions,
+      },
+    );
+  },
+
+  async balance(
+    customer_id: string,
+    filter: Customer.BalanceFilter,
+  ): Promise<Result<Customer.BalanceResponse>> {
+    const token = await client.getAccessToken();
+    if (!token.ok) {
+      return err(token.error);
+    }
+
+    const queryString = buildQueryString(filter);
+
+    return httpClient.get<Customer.BalanceResponse>(
+      `${client.config.baseUrl}/api/v1/customers/${customer_id}/balance${queryString}`,
+      {
+        headers: {
+          Authorization: `Bearer ${token.value}`,
+        },
+        retryOptions: client.retryOptions,
+      },
+    );
+  },
 });
diff --git a/packages/api/src/types/customer.ts b/packages/api/src/types/customer.ts
index 7fc2a00..6cdb73b 100644
--- a/packages/api/src/types/customer.ts
+++ b/packages/api/src/types/customer.ts
@@ -53,6 +53,23 @@ export namespace Customer {
     account_type?: string | null;
   }
 
+  type Provider =
+    | "stripe"
+    | "bridge"
+    | "pagar_me"
+    | "brla"
+    | "avenia"
+    | "mercado_pago";
+
+  type SyncField = "shipping" | "email" | "first_name" | "last_name";
+
+  export interface Sync {
+    providers: [Provider]; // exactly 1
+    fields: SyncField[];
+  }
+
+  export type SyncResponse = ApiResponse<null>;
+
   export interface Request extends Partial<Base> {}
 
   export type Response = ApiResponse<Data>;
@@ -72,4 +89,35 @@ export namespace Customer {
     document_type?: string;
     country_code?: string;
   }
+  export interface BalanceFilter {
+    provider: string;
+    role: string;
+  }
+
+  export interface BalanceResponse
+    extends ApiResponse<{
+      as_of: string;
+      filters: {
+        customer_id: string;
+        provider?: string;
+        role?: string;
+      };
+
+      balances: {
+        account_id: string;
+        provider: string;
+        customer: {
+          id: string;
+          role: string;
+        };
+        as_of: string;
+        totals: {
+          currency: string;
+          amount: number;
+          pending: number;
+          reserved: number;
+          instant_payouts: number;
+        }[];
+      }[];
+    }> {}
 }