diff --git a/simple-counter/tests/tests.rs b/simple-counter/tests/tests.rs
new file mode 100644
index 0000000..b762257
--- /dev/null
+++ b/simple-counter/tests/tests.rs
@@ -0,0 +1,120 @@
+use near_sdk::serde::{Deserialize, Serialize};
+use serde_json::json;
+use workspaces::prelude::*;
+use workspaces::{network::Sandbox, Account, Contract, Worker};
+
+const WASM_FILEPATH: &str = "../out/simple_counter.wasm";
+
+#[derive(Serialize, Deserialize)]
+pub struct Transaction {
+    value: u64,
+}
+
+async fn init() -> anyhow::Result<(Account, Account, Transaction, Contract, Worker<Sandbox>)> {
+    let sandbox = workspaces::sandbox().await?;
+    let wasm = std::fs::read(WASM_FILEPATH)?;
+    let contract = sandbox.dev_deploy(&wasm).await?;
+
+    let owner = sandbox.root_account().unwrap();
+    let alice = owner
+        .create_subaccount(&sandbox, "alice")
+        .transact()
+        .await?
+        .into_result()?;
+
+    let bob = owner
+        .create_subaccount(&sandbox, "bob")
+        .transact()
+        .await?
+        .into_result()?;
+
+    let transaction = Transaction { value: 10 };
+
+    contract
+        .call(&sandbox, "new")
+        .args_json(json!({"val": 100, "auths": vec![alice.id()]}))?
+        .transact()
+        .await?;
+
+    Ok((alice, bob, transaction, contract, sandbox))
+}
+
+#[tokio::test]
+async fn test_increment() -> anyhow::Result<()> {
+    let (alice, _, transaction, contract, sandbox) = init().await?;
+
+    let start_counter: u64 = alice
+        .call(&sandbox, contract.id(), "get_num")
+        .args_json(json!({}))?
+        .transact()
+        .await?
+        .json()?;
+
+    alice
+        .call(&sandbox, contract.id(), "increment")
+        .args_json(json!({ "trans": transaction }))?
+        .transact()
+        .await?;
+
+    let end_counter: u64 = alice
+        .call(&sandbox, contract.id(), "get_num")
+        .args_json(json!({}))?
+        .transact()
+        .await?
+        .json()?;
+
+    assert_eq!(end_counter, start_counter + transaction.value);
+    println!("Increment ✅");
+    Ok(())
+}
+
+#[tokio::test]
+async fn test_decrement() -> anyhow::Result<()> {
+    let (alice, _, transaction, contract, sandbox) = init().await?;
+
+    let start_counter: u64 = alice
+        .call(&sandbox, contract.id(), "get_num")
+        .args_json(json!({}))?
+        .transact()
+        .await?
+        .json()?;
+
+    alice
+        .call(&sandbox, contract.id(), "decrement")
+        .args_json(json!({ "trans": transaction }))?
+        .transact()
+        .await?;
+
+    let end_counter: u64 = alice
+        .call(&sandbox, contract.id(), "get_num")
+        .args_json(json!({}))?
+        .transact()
+        .await?
+        .json()?;
+
+    assert_eq!(end_counter, start_counter - transaction.value);
+    println!("Decrement ✅");
+    Ok(())
+}
+
+#[tokio::test]
+async fn test_reset() -> anyhow::Result<()> {
+    let (alice, _, _, contract, sandbox) = init().await?;
+
+    alice
+        .call(&sandbox, contract.id(), "reset")
+        .args_json(json!({}))?
+        .transact()
+        .await?;
+
+    let reset_counter: u64 = alice
+        .call(&sandbox, contract.id(), "get_num")
+        .args_json(json!({}))?
+        .transact()
+        .await?
+        .json()?;
+
+    assert_eq!(reset_counter, 0);
+    println!("Reset ✅");
+    Ok(())
+}