diff --git a/README.md b/README.md
index 493f319..b835ef5 100644
--- a/README.md
+++ b/README.md
@@ -24,6 +24,12 @@ implementation 'com.stripe:mpp-java:0.1.4'
```
+## Breaking change: custom Tempo memos
+
+`TempoMethod.Builder.memo(...)` and `Method.memo()` have been removed. Remove these
+configurations and overrides; clients use automatic challenge-bound attribution
+memos. Direct Tempo verification rejects explicit memos in payment requests.
+
## Usage
### Testnet
diff --git a/src/main/java/com/stripe/mpp/methods/tempo/Attribution.java b/src/main/java/com/stripe/mpp/methods/tempo/Attribution.java
index b3fa1b2..d25d0c0 100644
--- a/src/main/java/com/stripe/mpp/methods/tempo/Attribution.java
+++ b/src/main/java/com/stripe/mpp/methods/tempo/Attribution.java
@@ -11,7 +11,7 @@
/**
* MPP attribution memo encoding for TIP-20 {@code transferWithMemo}.
*
- * When the merchant does not set an explicit memo, Tempo clients write this
+ *
Tempo clients write this
* 32-byte value so a payment can be bound to a specific challenge. Layout:
*
*
diff --git a/src/main/java/com/stripe/mpp/methods/tempo/TempoChargeIntent.java b/src/main/java/com/stripe/mpp/methods/tempo/TempoChargeIntent.java
index 5e4ee9c..db86c9f 100644
--- a/src/main/java/com/stripe/mpp/methods/tempo/TempoChargeIntent.java
+++ b/src/main/java/com/stripe/mpp/methods/tempo/TempoChargeIntent.java
@@ -29,7 +29,7 @@
*
*
* A qualifying Transfer of the requested token, recipient and amount is not
- * enough. Unless the merchant set an explicit memo, the matched logs must include
+ * enough. The matched logs must include
* a {@code TransferWithMemo} whose memo is bound to this challenge (MPP attribution
* tag, server fingerprint of the challenge realm, and nonce
* {@code keccak256(challengeId)[0..6]}). That is what stops a third party from
@@ -102,6 +102,9 @@ public TempoChargeIntent(String rpcUrl, Store store) {
@Override
@SuppressWarnings("unchecked")
public Receipt verify(Credential credential, Map request) {
+ if (memoFrom(request) != null) {
+ throw new VerificationFailedException("explicit memos are not supported for direct Tempo charge verification");
+ }
if (!(credential.payload() instanceof Map)) {
throw new VerificationFailedException("missing or invalid payload");
}
@@ -160,9 +163,7 @@ private Receipt awaitReceipt(
"transaction logs contain no Transfer matching the request currency, recipient, and amount"
);
}
- if (memoFrom(request) == null) {
- assertChallengeBoundMemo(matched, credential);
- }
+ assertChallengeBoundMemo(matched, credential);
return Receipt.success(txHash, "tempo");
}
if (i < maxRetries - 1) {
@@ -179,7 +180,7 @@ private Receipt awaitReceipt(
/**
* Collects ERC-20 Transfer / TransferWithMemo logs that match the request's
- * currency, recipient, amount, expected sender, and (when set) merchant memo.
+ * currency, recipient, amount, and expected sender.
*
* The request amount must already be in atomic units (i.e. after
* transformRequest has run).
@@ -193,7 +194,6 @@ private List matchTransferLogs(
String currency = (String) request.get("currency");
String recipient = (String) request.get("recipient");
String amountStr = (String) request.get("amount");
- String expectedMemo = normalizeMemo(memoFrom(request));
if (currency == null || recipient == null || amountStr == null) return List.of();
@@ -222,7 +222,6 @@ private List matchTransferLogs(
boolean isTransferWithMemo = TRANSFER_WITH_MEMO_TOPIC.equalsIgnoreCase(topic0);
if (!isTransfer && !isTransferWithMemo) continue;
if (isTransferWithMemo && topics.size() < 4) continue;
- if (expectedMemo != null && !isTransferWithMemo) continue;
String fromAddress = "0x" + topics.get(1).substring(topics.get(1).length() - 40);
String toAddress = "0x" + topics.get(2).substring(topics.get(2).length() - 40);
@@ -230,11 +229,6 @@ private List matchTransferLogs(
if (!toAddress.equalsIgnoreCase(recipient)) continue;
if (expectedSender != null && !fromAddress.equalsIgnoreCase(expectedSender)) continue;
- if (expectedMemo != null) {
- String logMemo = normalizeMemo(topics.get(3));
- if (logMemo == null || !logMemo.equals(expectedMemo)) continue;
- }
-
String data = (String) log.get("data");
if (data == null || data.length() < 66) continue;
@@ -317,14 +311,6 @@ static String memoFrom(Map request) {
return null;
}
- static String normalizeMemo(String memo) {
- if (memo == null) return null;
- String value = memo.trim();
- if (value.isEmpty()) return null;
- if (!value.startsWith("0x") && !value.startsWith("0X")) value = "0x" + value;
- return value.toLowerCase(Locale.ROOT);
- }
-
static final class ParsedPkh {
final String address;
final int chainId;
diff --git a/src/main/java/com/stripe/mpp/methods/tempo/TempoMethod.java b/src/main/java/com/stripe/mpp/methods/tempo/TempoMethod.java
index ee0a8f9..217d990 100644
--- a/src/main/java/com/stripe/mpp/methods/tempo/TempoMethod.java
+++ b/src/main/java/com/stripe/mpp/methods/tempo/TempoMethod.java
@@ -26,26 +26,20 @@ public class TempoMethod implements Method {
private final String rpcUrl;
private final int chainId;
private final int decimals;
- private final String memo;
private final TempoChargeIntent chargeIntent;
TempoMethod(String rpcUrl, int chainId) {
- this(rpcUrl, chainId, TempoDefaults.DEFAULT_DECIMALS, null, null, null);
+ this(rpcUrl, chainId, TempoDefaults.DEFAULT_DECIMALS, null, null);
}
TempoMethod(String rpcUrl, int chainId, int decimals, TempoRelay relay) {
- this(rpcUrl, chainId, decimals, relay, null, null);
+ this(rpcUrl, chainId, decimals, relay, null);
}
TempoMethod(String rpcUrl, int chainId, int decimals, TempoRelay relay, Store store) {
- this(rpcUrl, chainId, decimals, relay, store, null);
- }
-
- TempoMethod(String rpcUrl, int chainId, int decimals, TempoRelay relay, Store store, String memo) {
this.rpcUrl = rpcUrl;
this.chainId = chainId;
this.decimals = decimals;
- this.memo = memo;
this.chargeIntent = relay == null
? new TempoChargeIntent(rpcUrl, store != null ? store : new MemoryStore())
: new TempoRelayChargeIntent(rpcUrl, relay);
@@ -66,7 +60,6 @@ public static final class Builder {
private int chainId = TempoDefaults.MAINNET_CHAIN_ID;
private TempoRelay relay;
private Store store;
- private String memo;
private Builder() {}
@@ -103,28 +96,13 @@ public Builder store(Store store) {
return this;
}
- /**
- * Sets an explicit TIP-20 memo that payments must match.
- *
- * When omitted, clients write an MPP attribution memo bound to the
- * challenge and the server requires that binding. An explicit memo is
- * matched exactly and is not challenge-bound — the caller must make it
- * unique per challenge if hash reuse across challenges should be rejected.
- */
- public Builder memo(String memo) {
- this.memo = Objects.requireNonNull(memo, "memo");
- return this;
- }
-
public TempoMethod build() {
- return new TempoMethod(rpcUrl, chainId, TempoDefaults.DEFAULT_DECIMALS, relay, store, memo);
+ return new TempoMethod(rpcUrl, chainId, TempoDefaults.DEFAULT_DECIMALS, relay, store);
}
}
@Override public String name() { return "tempo"; }
- @Override public String memo() { return memo; }
-
public int chainId() { return chainId; }
public String rpcUrl() { return rpcUrl; }
/** Returns the CAIP-2 network string (e.g. {@code "eip155:4217"}) for display purposes. */
@@ -154,11 +132,7 @@ public Map transformRequest(Map request) {
.toString();
Map result = new LinkedHashMap<>(request);
result.put("amount", atomic);
- Map methodDetails = new LinkedHashMap<>();
- methodDetails.put("chainId", chainId);
- Object requestMemo = result.get("memo");
- if (requestMemo != null) methodDetails.put("memo", requestMemo);
- result.put("methodDetails", methodDetails);
+ result.put("methodDetails", Map.of("chainId", chainId));
return result;
} catch (Exception e) {
throw new IllegalArgumentException("invalid amount: " + amount, e);
diff --git a/src/main/java/com/stripe/mpp/server/Method.java b/src/main/java/com/stripe/mpp/server/Method.java
index 8fe1319..2868dc1 100644
--- a/src/main/java/com/stripe/mpp/server/Method.java
+++ b/src/main/java/com/stripe/mpp/server/Method.java
@@ -18,9 +18,6 @@ public interface Method {
*/
List> intents();
- /** Optional: blockchain/network memo field. */
- default String memo() { return null; }
-
/** Optional: fee payer address. */
default String feePayer() { return null; }
diff --git a/src/main/java/com/stripe/mpp/server/MppHandler.java b/src/main/java/com/stripe/mpp/server/MppHandler.java
index 7893862..807b537 100644
--- a/src/main/java/com/stripe/mpp/server/MppHandler.java
+++ b/src/main/java/com/stripe/mpp/server/MppHandler.java
@@ -121,7 +121,6 @@ public VerifyResult charge(
request.put("amount", resolvedAmount);
request.put("currency", resolvedCurrency);
request.put("recipient", resolvedRecipient);
- if (method.memo() != null) request.put("memo", method.memo());
if (method.feePayer() != null) request.put("fee_payer", method.feePayer());
if (method.chain() != null) request.put("chain", method.chain());
@@ -203,7 +202,6 @@ Map buildRequest(ChargeDescriptor d) {
request.put("amount", resolvedAmount);
request.put("currency", resolvedCurrency);
request.put("recipient", resolvedRecipient);
- if (method.memo() != null) request.put("memo", method.memo());
if (method.feePayer() != null) request.put("fee_payer", method.feePayer());
if (method.chain() != null) request.put("chain", method.chain());
diff --git a/src/test/java/com/stripe/mpp/methods/tempo/TempoChargeIntentTest.java b/src/test/java/com/stripe/mpp/methods/tempo/TempoChargeIntentTest.java
index edbee7c..ecca9f2 100644
--- a/src/test/java/com/stripe/mpp/methods/tempo/TempoChargeIntentTest.java
+++ b/src/test/java/com/stripe/mpp/methods/tempo/TempoChargeIntentTest.java
@@ -8,6 +8,7 @@
import com.stripe.mpp.store.Store;
import org.junit.jupiter.api.Test;
import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.CsvSource;
import org.junit.jupiter.params.provider.ValueSource;
import java.util.HashMap;
@@ -113,6 +114,7 @@ static class StubRpc extends TempoRpc {
private final Map receipt;
private final int nullReceiptsBeforeResult;
private int receiptCalls = 0;
+ private int sendCalls = 0;
StubRpc(String txHashOnSend, Map receipt, int nullReceiptsBeforeResult) {
this.txHashOnSend = txHashOnSend;
@@ -120,7 +122,10 @@ static class StubRpc extends TempoRpc {
this.nullReceiptsBeforeResult = nullReceiptsBeforeResult;
}
- @Override String sendRawTransaction(String rpcUrl, String rawTx) { return txHashOnSend; }
+ @Override String sendRawTransaction(String rpcUrl, String rawTx) {
+ sendCalls++;
+ return txHashOnSend;
+ }
@Override Map getTransactionReceipt(String rpcUrl, String txHash) {
return receiptCalls++ < nullReceiptsBeforeResult ? null : receipt;
@@ -408,58 +413,35 @@ void pushAcceptsChallengeBoundMemoAlongsideAPlainTransfer() {
assertThat(result.status()).isEqualTo("success");
}
- @Test
- void explicitMemoMustMatchExactly() {
- String merchantMemo = "0x" + "ab".repeat(32);
- Map request = new HashMap<>(REQUEST);
- request.put("memo", merchantMemo);
-
- Receipt result = intent(new StubRpc(null,
- receiptWithMemoLog(TOKEN_CONTRACT, SENDER, RECIPIENT, AMOUNT_ATOMIC, merchantMemo), 0))
- .verify(hashCredential("0xpushedtx"), request);
- assertThat(result.status()).isEqualTo("success");
- }
-
- @Test
- void explicitMemoMismatchIsRejected() {
+ @ParameterizedTest
+ @CsvSource({
+ "hash, false, false", "hash, false, true",
+ "hash, true, false", "hash, true, true",
+ "transaction, false, false", "transaction, false, true",
+ "transaction, true, false", "transaction, true, true"
+ })
+ void explicitMemoIsRejectedBeforeRpc(String type, boolean nested, boolean declaredPayer) {
String merchantMemo = "0x" + "ab".repeat(32);
- String otherMemo = "0x" + "cd".repeat(32);
Map request = new HashMap<>(REQUEST);
- request.put("memo", merchantMemo);
+ if (nested) {
+ request.put("methodDetails", Map.of("chainId", CHAIN_ID, "memo", merchantMemo));
+ } else {
+ request.put("memo", merchantMemo);
+ }
+ Credential credential = new Credential(ECHO,
+ "hash".equals(type) ? Map.of("type", type, "hash", "0xstolen")
+ : Map.of("type", type, "signature", "0xsignedtx"),
+ declaredPayer ? didPkh(CHAIN_ID, SENDER) : null);
+ StubRpc rpc = new StubRpc("0xstolen",
+ receiptWithMemoLog(TOKEN_CONTRACT, SENDER, RECIPIENT, AMOUNT_ATOMIC, merchantMemo), 0);
+ Store store = new MemoryStore();
- assertThatThrownBy(() -> intent(new StubRpc(null,
- receiptWithMemoLog(TOKEN_CONTRACT, SENDER, RECIPIENT, AMOUNT_ATOMIC, otherMemo), 0))
- .verify(hashCredential("0xpushedtx"), request))
+ assertThatThrownBy(() -> intent(rpc, store).verify(credential, request))
.isInstanceOf(VerificationFailedException.class)
- .hasMessageContaining("Transfer");
- }
-
- @Test
- void explicitMemoDoesNotRequireChallengeBinding() {
- String merchantMemo = "0x" + "ab".repeat(32);
- Map request = new HashMap<>(REQUEST);
- request.put("memo", merchantMemo);
-
- Receipt result = intent(new StubRpc(null,
- receiptWithMemoLog(TOKEN_CONTRACT, SENDER, RECIPIENT, AMOUNT_ATOMIC, merchantMemo), 0))
- .verify(hashCredential("0xpushedtx"), request);
- assertThat(result.status()).isEqualTo("success");
- }
-
- @Test
- void explicitMemoInMethodDetailsIsHonored() {
- String merchantMemo = "0x" + "ab".repeat(32);
- Map request = Map.of(
- "amount", String.valueOf(AMOUNT_ATOMIC),
- "currency", TOKEN_CONTRACT,
- "recipient", RECIPIENT,
- "methodDetails", Map.of("chainId", CHAIN_ID, "memo", merchantMemo)
- );
-
- Receipt result = intent(new StubRpc(null,
- receiptWithMemoLog(TOKEN_CONTRACT, SENDER, RECIPIENT, AMOUNT_ATOMIC, merchantMemo), 0))
- .verify(hashCredential("0xpushedtx"), request);
- assertThat(result.status()).isEqualTo("success");
+ .hasMessageContaining("explicit memos are not supported");
+ assertThat(rpc.sendCalls).isZero();
+ assertThat(rpc.receiptCalls).isZero();
+ assertThat(store.tryClaim("tempo:hash:0xstolen")).isTrue();
}
@Test
diff --git a/src/test/java/com/stripe/mpp/methods/tempo/TempoMethodTest.java b/src/test/java/com/stripe/mpp/methods/tempo/TempoMethodTest.java
index 824c5a0..57df0c6 100644
--- a/src/test/java/com/stripe/mpp/methods/tempo/TempoMethodTest.java
+++ b/src/test/java/com/stripe/mpp/methods/tempo/TempoMethodTest.java
@@ -1,8 +1,5 @@
package com.stripe.mpp.methods.tempo;
-import com.stripe.mpp.Mpp;
-import com.stripe.mpp.server.MppHandler;
-import com.stripe.mpp.server.VerifyResult;
import org.junit.jupiter.api.Test;
import java.util.Map;
@@ -48,37 +45,4 @@ void rejectsAmountWithTooManyDecimalPlaces() {
)).isInstanceOf(IllegalArgumentException.class);
}
- @Test
- void copiesMemoIntoMethodDetails() {
- Map result = METHOD.transformRequest(Map.of(
- "amount", "1.000000",
- "currency", "USDC",
- "recipient", "0xABC",
- "memo", "0x" + "ab".repeat(32)
- ));
- assertThat(((Map) result.get("methodDetails")).get("chainId")).isEqualTo(1);
- assertThat(((Map) result.get("methodDetails")).get("memo"))
- .isEqualTo("0x" + "ab".repeat(32));
- assertThat(result.get("memo")).isEqualTo("0x" + "ab".repeat(32));
- }
-
- @Test
- void builderMemoIsAdvertisedOnTheMethod() {
- String memo = "0x" + "cd".repeat(32);
- TempoMethod method = TempoMethod.custom("http://rpc.example.com", 1).memo(memo).build();
- assertThat(method.memo()).isEqualTo(memo);
- }
-
- @Test
- void challengeIncludesConfiguredMemo() {
- String memo = "0x" + "ab".repeat(32);
- TempoMethod tempo = TempoMethod.custom("http://rpc.example.com", 1).memo(memo).build();
- MppHandler mpp = Mpp.create(tempo, "api.example.com", "secret");
-
- VerifyResult result = mpp.charge(null, tempo.chargeIntent(), "1.000000", "USDC", "0xABC");
-
- Map request = ((VerifyResult.Challenged) result).challenge().request();
- assertThat(request.get("memo")).isEqualTo(memo);
- assertThat(((Map) request.get("methodDetails")).get("memo")).isEqualTo(memo);
- }
}