> ## Documentation Index
> Fetch the complete documentation index at: https://developers.stellar.org/llms.txt
> Use this file to discover all available pages before exploring further.

# URI Scheme to facilitate delegated signing

> The [Sep-7] standard defines a way for a non-wallet application to construct a URI scheme that represents a specific transaction for an account to sign.

> [!NOTE]
>
> This guide is available on four different programming languages: Typescript, Kotlin, Flutter (Dart) and Swift. You can change the shown version on each page via the buttons above.

> [!CAUTION]
>
> **Important**
>
> Documentation for this language is currently work in progress. Some of information may not be applicable for this language, or missing. Code samples may be incomplete.

The [Sep-7] standard defines a way for a non-wallet application to construct a URI scheme that represents a specific transaction for an account to sign. The scheme used is `web+stellar`, followed by a colon. Example: `web+stellar:<operation>?<param1>=<value1>&<param2>=<value2>`

## Tx Operation

The tx operation represents a request to sign a specific transaction envelope, with [some configurable parameters].

> [tab] TypeScript
>
> ```typescript theme={"theme":{"light":"github-light","dark":"github-dark"}}
> const sourceAccountKeyPair = "G...";
> const destinationAccountKeyPair = "G...";
> const txBuilder = await stellar.transaction({
>   sourceAddress: sourceAccountKeyPair,
> });
> const tx = txBuilder.createAccount(destinationAccountKeyPair).build();
> const xdr = encodeURIComponent(tx.toEnvelope().toXDR().toString("base64"));
> const callback = encodeURIComponent("https://example.com/callback");
> const txUri = `web+stellar:tx?xdr=${xdr}&callback=${callback}`;
> const uri = wallet.parseSep7Uri(txUri);
> // uri can be parsed and transaction can be signed/submitted by an application that implements Sep-7
> ```

> [tab] Flutter
>
> ```dart theme={"theme":{"light":"github-light","dark":"github-dark"}}
> final sourceAccountKeyPair = PublicKeyPair.fromAccountId('G...');
> final destinationAccountKeyPair = PublicKeyPair.fromAccountId('G...');
> var txBuilder = await stellar.transaction(sourceAccountKeyPair);
> final tx = txBuilder.createAccount(destinationAccountKeyPair).build();
> final xdr = Uri.encodeComponent(tx.toEnvelopeXdrBase64());
> final callback = Uri.encodeComponent('https://example.com/callback');
> final txUri = 'web+stellar:tx?xdr=$xdr&callback=$callback';
> final uri = wallet.parseSep7Uri(txUri);
> // uri can be parsed and transaction can be signed/submitted by an application that implements Sep-7
> ```

> [tab] Swift
>
> ```swift theme={"theme":{"light":"github-light","dark":"github-dark"}}
> let sourceAccountKeyPair = try PublicKeyPair(accountId: "G...")
> let destinationAccountKeyPair = try PublicKeyPair(accountId: "G...")
> let txBuilder = try await stellar.transaction(sourceAddress: sourceAccountKeyPair)
> let tx = try txBuilder.createAccount(newAccount: destinationAccountKeyPair).build()
> let xdr = try tx.encodedEnvelope().addingPercentEncoding(withAllowedCharacters: .urlHostAllowed) // url encoded
> let callback = "https://example.com/callback".addingPercentEncoding(withAllowedCharacters: .urlHostAllowed)  // url encoded
> let txUri = "web+stellar:tx?xdr=\(xdr!)&callback=\(callback!)"
> let uri = try wallet.parseSep7Uri(uri: txUri)
> // uri can be parsed and transaction can be signed/submitted by an application that implements Sep-7
> ```

You can set replacements to be made in the xdr for specific fields by the application, these will be added in the [Sep-11 transaction representation format] to the URI.

> [tab] TypeScript
>
> ```typescript theme={"theme":{"light":"github-light","dark":"github-dark"}}
> const uri = new Sep7Tx(txUri);
> uri.addReplacement({
>   id: "X",
>   path: "sourceAccount",
>   hint: "account from where you want to pay fees",
> });
> ```

> [tab] Flutter
>
> ```dart theme={"theme":{"light":"github-light","dark":"github-dark"}}
> final uri = wallet.parseSep7Uri(txUri);
>
> if (uri is Sep7Tx) {
>     uri.addReplacement(Sep7Replacement(
>         id: 'X',
>         path: 'sourceAccount',
>         hint: 'account from where you want to pay fees'));
> }
> ```

> [tab] Swift
>
> ```swift theme={"theme":{"light":"github-light","dark":"github-dark"}}
> let uri = try wallet.parseSep7Uri(uri: txUri)
>
> if let uri = uri as? Sep7Tx {
>     let replacement = Sep7Replacement(id:"X",
>                                       path:"sourceAccount",
>                                       hint: "account from where you want to pay fees")
>
>     uri.addReplacement(replacement: replacement)
> }
> ```

You can assign parameters after creating the initial instance using the appropriate setter for the parameter.

> [tab] TypeScript
>
> ```typescript theme={"theme":{"light":"github-light","dark":"github-dark"}}
> const sourceAccountKeyPair = "G...";
> const destinationAccountKeyPair = "G...";
> const txBuilder = await stellar.transaction({
>   sourceAddress: sourceAccountKeyPair,
> });
> const tx = txBuilder.createAccount(destinationAccountKeyPair).build();
> const uri = wallet.Sep7Tx.forTransaction(tx);
> uri.callback = "https://example.com/callback";
> uri.msg = "here goes a message";
> uri.toString(); // encodes everything and converts to a uri string
> ```

> [tab] Flutter
>
> ```dart theme={"theme":{"light":"github-light","dark":"github-dark"}}
> final sourceAccountKeyPair = PublicKeyPair.fromAccountId('G...');
> final destinationAccountKeyPair = PublicKeyPair.fromAccountId('G...');
> var txBuilder = await stellar.transaction(sourceAccountKeyPair);
> final tx = txBuilder.createAccount(destinationAccountKeyPair).build();
>
> final uri = Sep7Tx.forTransaction(tx);
> uri.setCallback('https://example.com/callback');
> uri.setMsg('here goes a message');
> uri.toString(); // encodes everything and converts to a uri string
> ```

> [tab] Swift
>
> ```swift theme={"theme":{"light":"github-light","dark":"github-dark"}}
> let sourceAccountKeyPair = try PublicKeyPair(accountId: "G...")
> let destinationAccountKeyPair = try PublicKeyPair(accountId: "G...")
> let txBuilder = try await stellar.transaction(sourceAddress: sourceAccountKeyPair)
> let tx = try txBuilder.createAccount(newAccount: destinationAccountKeyPair).build()
>
> let uri = try Sep7Tx(transaction: tx)
> uri.setCallback(callback: "https://example.com/callback")
> try uri.setMsg(msg: "here goes a message")
> let uriStr = uri.toString() // encodes everything and converts to a uri string
> ```

## Pay Operation

The pay operation represents a request to pay a specific address with a specific asset, regardless of the source asset used by the payer. You can [configure parameters] to build the payment operation.

> [tab] TypeScript
>
> ```typescript theme={"theme":{"light":"github-light","dark":"github-dark"}}
> const destination = "G...";
> const assetIssuer = "G...";
> const assetCode = "USDC";
> const amount = "120.1234567";
> const memo = "memo";
> const message = encodeURIComponent("pay me with lumens");
> const originDomain = "example.com";
> const payUri = `web+stellar:pay?destination=${destination}&amount=${amount}&memo=${memo}&msg=${message}&origin_domain=${originDomain}&asset_issuer=${assetIssuer}&asset_code=${assetCode}`;
> const uri = parseSep7Uri(payUri);
> // uri can be parsed and transaction can be built/signed/submitted by an application that implements Sep-7
> ```

> [tab] Flutter
>
> ```dart theme={"theme":{"light":"github-light","dark":"github-dark"}}
> const destination = 'G...';
> const assetIssuer = 'G...';
> const assetCode = 'USDC';
> const amount = '120.1234567';
> const memo = 'memo';
> final message = Uri.encodeComponent('pay me with lumens');
> const originDomain = 'example.com';
> final payUri = 'web+stellar:pay?destination=$destination&amount=$amount&memo=$memo&msg=$message&origin_domain=$originDomain&asset_issuer=$assetIssuer&asset_code=$assetCode';
> final uri = Sep7.parseSep7Uri(payUri);
> // uri can be parsed and transaction can be built/signed/submitted by an application that implements Sep-7
> ```

> [tab] Swift
>
> ```swift theme={"theme":{"light":"github-light","dark":"github-dark"}}
> let destination = "G..."
> let assetIssuer = "G..."
> let assetCode = "USDC"
> let amount = "120.1234567"
> let memo = "memo"
> let message = "pay me with lumens".addingPercentEncoding(withAllowedCharacters: .urlHostAllowed) // url encoded
> let originDomain = "example.com"
> let payUri = "web+stellar:pay?destination=\(destination)&amount=\(amount)&memo=\(memo)&msg=\(message!)&origin_domain=\(originDomain)&asset_issuer=\(assetIssuer)&asset_code=\(assetCode)"
> uri = try Sep7.parseSep7Uri(uri: payUri)
> // uri can be parsed and transaction can be built/signed/submitted by an application that implements Sep-7
> ```

You can assign parameters after creating the initial instance using the appropriate setter for the parameter.

> [tab] TypeScript
>
> ```typescript theme={"theme":{"light":"github-light","dark":"github-dark"}}
> const uri = wallet.Sep7Pay.forDestination("G...");
> uri.callback = "https://example.com/callback";
> uri.msg = "here goes a message";
> uri.assetCode = "USDC";
> uri.assetIssuer = "G...";
> uri.amount = "10";
> uri.toString(); // encodes everything and converts to a uri string
> ```

> [tab] Flutter
>
> ```dart theme={"theme":{"light":"github-light","dark":"github-dark"}}
> final uri = Sep7Pay.forDestination('G...');
> uri.setCallback('https://example.com/callback');
> uri.setMsg('here goes a message');
> uri.setAssetCode('USDC');
> uri.setAssetIssuer('G...');
> uri.setAmount('10');
> uri.toString(); // encodes everything and converts to a uri string
> ```

> [tab] Swift
>
> ```swift theme={"theme":{"light":"github-light","dark":"github-dark"}}
> let uri = Sep7Pay(destination: "G...")
> uri.setCallback(callback: "https://example.com/callback")
> try uri.setMsg(msg: "here goes a message")
> uri.setAssetCode(assetCode: "USDC")
> uri.setAssetIssuer(assetIssuer: "G...")
> uri.setAmount(amount: "10")
> uri.toString() // encodes everything and converts to a uri string
> ```

The last step after building a `Sep7Tx` or `Sep7Pay` is to add a signature to your uri. This will create a payload out of the transaction and sign it with the provided keypair.

> [tab] TypeScript
>
> ```typescript theme={"theme":{"light":"github-light","dark":"github-dark"}}
> const uri = wallet.Sep7Pay.forDestination("G...");
> uri.originDomain = "example.com";
> const keypair = wallet.stellar().account().createKeypair();
> uri.addSignature(Keypair.fromSecret(keypair.secretKey));
> console.log(uri.signature); // signed uri payload
> ```

> [tab] Flutter
>
> ```dart theme={"theme":{"light":"github-light","dark":"github-dark"}}
> final uri = Sep7Pay.forDestination('G...');
> uri.setOriginDomain('example.com');
> final keypair = wallet.stellar().account().createKeyPair();
> uri.addSignature(keypair);
> print(uri.getSignature()); // signed uri payload
> ```

> [tab] Swift
>
> ```swift theme={"theme":{"light":"github-light","dark":"github-dark"}}
> uri = Sep7Pay(destination: "G..")
> uri.setOriginDomain(originDomain: "example.com")
> let keyPair = wallet.stellar.account.createKeyPair()
> try uri.addSignature(keyPair: keyPair)
> print(uri.getSignature()) // signed uri payload
> ```

The signature can then be verified by fetching the [Stellar toml file] from the origin domain in the uri, and using the included signing key to verify the uri signature. This is all done as part of the `verifySignature` method.

> [tab] TypeScript
>
> ```typescript theme={"theme":{"light":"github-light","dark":"github-dark"}}
> const passesVerification = await uri.verifySignature(); // true or false
> ```

> [tab] Flutter
>
> ```dart theme={"theme":{"light":"github-light","dark":"github-dark"}}
> final passesVerification = await uri.verifySignature(); // true or false
> ```

> [tab] Swift
>
> ```swift theme={"theme":{"light":"github-light","dark":"github-dark"}}
> let passesVerification = await uri.verifySignature() // true or false
> ```

[Sep-7]: https://github.com/stellar/stellar-protocol/blob/master/ecosystem/sep-0007.md

[Sep-11 transaction representation format]: https://github.com/stellar/stellar-protocol/blob/master/ecosystem/sep-0011.md

[some configurable parameters]: https://github.com/stellar/stellar-protocol/blob/master/ecosystem/sep-0007.md#operation-tx

[configure parameters]: https://github.com/stellar/stellar-protocol/blob/master/ecosystem/sep-0007.md#operation-pay

[Stellar toml file]: https://developers.stellar.org/docs/build/apps/example-application-tutorial/anchor-integration/sep1.md