diff --git a/docs-src/usage/payment_requests.md b/docs-src/usage/payment_requests.md
index 2c695317e..7f5497306 100644
--- a/docs-src/usage/payment_requests.md
+++ b/docs-src/usage/payment_requests.md
@@ -107,7 +107,7 @@ const request = new PaymentRequest({
 
 ### Receive the payload
 
-Payloads arrive as raw text from the payer's wallet, so parse with `decodePayload` rather than `JSON.parse` (which silently corrupts amounts above 2^53). It validates the shape and normalizes proof amounts to `bigint`; matching the payload to your request is your job:
+Payloads arrive as raw text from the payer's wallet, so parse with `decodePayload` rather than `JSON.parse` (which silently corrupts amounts above 2^53). It validates the shape and normalizes proof amounts to `Amount`, so the returned proofs are ready to use; matching the payload to your request is your job:
 
 ```typescript
 import { PaymentRequest, type PaymentRequestPayload } from '@cashu/cashu-ts';
diff --git a/etc/cashu-ts.api.md b/etc/cashu-ts.api.md
index 31d21acb0..3ebebda1c 100644
--- a/etc/cashu-ts.api.md
+++ b/etc/cashu-ts.api.md
@@ -888,6 +888,7 @@ export type MeltProofsConfig = {
     keysetId?: string;
     privkey?: string | string[];
     onCountersReserved?: OnCountersReserved;
+    nut08Change?: boolean;
 };
 
 // @public
@@ -1392,7 +1393,7 @@ export function normalizeSecpPubkey(pk: string): string;
 export type NUT10Option = {
     kind: string;
     data: string;
-    tags: string[][];
+    tags?: string[][];
 };
 
 // @public (undocumented)
@@ -1789,11 +1790,6 @@ export type PostRestoreResponse = {
     signatures: SerializedBlindedSignature[];
 };
 
-// @public (undocumented)
-export type PrepareMeltConfig = MeltProofsConfig & {
-    nut08Change?: boolean;
-};
-
 // @public
 export type PrivKey = Uint8Array | string;
 
@@ -1843,7 +1839,7 @@ export type RawMintKeys = {
 export type RawNUT10Option = {
     k: string;
     d: string;
-    t: string[][];
+    t?: string[][];
 };
 
 // @public (undocumented)
@@ -2333,7 +2329,9 @@ export class Wallet {
     completeMint(mintPreview: MintPreview<Pick<MintQuoteBaseResponse, 'quote'>>): Promise<Proof[]>;
     completeSwap(swapPreview: SwapPreview, privkey?: string | string[]): Promise<SendResponse>;
     readonly counters: WalletCounters;
-    createLockedMintQuote(amount: AmountLike, pubkey: string, description?: string): Promise<MintQuoteBolt11Response>;
+    createLockedMintQuote(amount: AmountLike, pubkey: string, description?: string): Promise<MintQuoteBolt11Response & {
+        pubkey: string;
+    }>;
     createMeltChangeProofs(outputData: OutputDataLike[], changeSigs: SerializedBlindedSignature[]): Proof[];
     createMeltQuote<TRes extends MeltQuoteBaseResponse = MeltQuoteGenericResponse>(method: string, payload: Record<string, unknown>, options?: {
         normalize?: (raw: Record<string, unknown>) => TRes;
@@ -2389,7 +2387,7 @@ export class Wallet {
         amount: AmountLike;
         quote: TQuote;
     }>, config?: MintProofsConfig, outputType?: OutputType): Promise<BatchMintPreview<TQuote>>;
-    prepareMelt<TQuote extends Pick<MeltQuoteBaseResponse, 'amount' | 'quote'>>(method: string, meltQuote: TQuote, proofsToSend: ProofLike[], config?: PrepareMeltConfig, outputType?: OutputType): Promise<MeltPreview<TQuote>>;
+    prepareMelt<TQuote extends Pick<MeltQuoteBaseResponse, 'amount' | 'quote'>>(method: string, meltQuote: TQuote, proofsToSend: ProofLike[], config?: MeltProofsConfig, outputType?: OutputType): Promise<MeltPreview<TQuote>>;
     prepareMint<TQuote extends Pick<MintQuoteBaseResponse, 'quote'>>(method: string, amount: AmountLike, quote: TQuote, config?: MintProofsConfig, outputType?: OutputType): Promise<MintPreview<TQuote>>;
     prepareSwapToReceive(token: Token | string | ProofLike[], config?: ReceiveConfig, outputType?: OutputType): Promise<SwapPreview>;
     prepareSwapToSend(amount: AmountLike, proofs: ProofLike[], config?: SendConfig, outputConfig?: OutputConfig): Promise<SwapPreview>;
diff --git a/migration-5.0.0.md b/migration-5.0.0.md
index 6d2d99037..3bf69b369 100644
--- a/migration-5.0.0.md
+++ b/migration-5.0.0.md
@@ -309,6 +309,48 @@ Calls that already pass a `CompleteMeltOptions` object (or omit the third argume
 
 ---
 
+## `PrepareMeltConfig` removed; `nut08Change` moved to `MeltProofsConfig`
+
+`PrepareMeltConfig` is removed. Its only distinction was `nut08Change`, which now lives on `MeltProofsConfig`, so every melt method takes the same config type. This also fixes the option being unusable through `meltProofs`, `meltProofsBolt11`, `meltProofsBolt12` and `meltProofsOnchain`: they forward their config to `prepareMelt`, so `nut08Change` worked at runtime but did not type check. In v4 the type remains as a deprecated alias of `MeltProofsConfig`.
+
+### Migration
+
+```ts
+// Before
+import { type PrepareMeltConfig } from '@cashu/cashu-ts';
+const config: PrepareMeltConfig = { nut08Change: false };
+
+// After
+import { type MeltProofsConfig } from '@cashu/cashu-ts';
+const config: MeltProofsConfig = { nut08Change: false };
+```
+
+Only the type name changes; the object shape is identical, so untyped call sites need no change.
+
+---
+
+## `NUT10Option.tags` is optional
+
+`NUT10Option.tags` and `RawNUT10Option.t` are now optional, matching NUT-10 and NUT-18, which both describe tags as optional. Constructing a payment request lock no longer needs a placeholder `tags: []`. Code that reads the field must handle `undefined`, which was already possible at runtime: decoding a request that omits tags produced one.
+
+### Migration
+
+```ts
+// Before
+if (request.nut10.tags.length > 0) {
+  /* … */
+}
+
+// After
+if (request.nut10.tags?.length) {
+  /* … */
+}
+```
+
+Absent and empty are equivalent, and neither is encoded.
+
+---
+
 ## `P2PKOptions` is now a `kind` + `data` spending condition
 
 `P2PKOptions` drops `pubkey: string | string[]` and `hashlock?`. It is now the NUT-10 envelope (`kind` + `data`) plus the shared NUT-11 `LockConditions` tags:
diff --git a/src/model/PaymentRequest.ts b/src/model/PaymentRequest.ts
index dd3108429..5417af5c8 100644
--- a/src/model/PaymentRequest.ts
+++ b/src/model/PaymentRequest.ts
@@ -252,7 +252,7 @@ export class PaymentRequest {
       if (typeof amount !== 'number' && typeof amount !== 'bigint') {
         throw new CTSError(`invalid payment payload: malformed proof amount at index ${i}`);
       }
-      return { ...p, amount: Amount.from(amount).toBigInt() } as unknown as Proof;
+      return { ...(p as Omit<Proof, 'amount'>), amount: Amount.from(amount) };
     });
     return {
       ...(id !== undefined && { id }),
diff --git a/src/model/types/NUT23.ts b/src/model/types/NUT23.ts
index f6fc95eab..bc8c81506 100644
--- a/src/model/types/NUT23.ts
+++ b/src/model/types/NUT23.ts
@@ -30,8 +30,12 @@ export type MintQuoteBolt11Response = MintQuoteBaseResponse & {
    */
   amount: Amount;
   /**
-   * State of the mint quote. Deprecated in NUT-04 in favour of the accounting fields; cashu-ts
-   * always populates it for bolt11.
+   * State of the mint quote. cashu-ts always populates it for bolt11, deriving it from the
+   * accounting fields when the mint omits it.
+   *
+   * @deprecated Deprecated in NUT-04 in favour of `amount_paid` / `amount_issued`; the mintable
+   *   amount is `amount_paid - amount_issued`. Retained for backwards compatibility and slated for
+   *   removal in a future major.
    */
   state: MintQuoteState;
 };
diff --git a/src/wallet/Wallet.ts b/src/wallet/Wallet.ts
index ccf5bc65d..90d1d18cb 100644
--- a/src/wallet/Wallet.ts
+++ b/src/wallet/Wallet.ts
@@ -88,7 +88,6 @@ import {
   type ReceiveConfig,
   type MintProofsConfig,
   type MeltProofsConfig,
-  type PrepareMeltConfig,
   type CompleteMeltOptions,
   type SwapTransaction,
   type MeltProofsResponse,
@@ -1990,7 +1989,7 @@ class Wallet {
     amount: AmountLike,
     pubkey: string,
     description?: string,
-  ): Promise<MintQuoteBolt11Response> {
+  ): Promise<MintQuoteBolt11Response & { pubkey: string }> {
     this.requireSupport('mint', 'bolt11');
     this.requireMintableKeyset('createLockedMintQuote');
     this.failIf(typeof pubkey !== 'string', 'A pubkey is required to lock the mint quote');
@@ -3188,7 +3187,7 @@ class Wallet {
     method: string,
     meltQuote: TQuote,
     proofsToSend: ProofLike[],
-    config?: PrepareMeltConfig,
+    config?: MeltProofsConfig,
     outputType?: OutputType,
   ): Promise<MeltPreview<TQuote>> {
     this.validateMeltQuote(meltQuote);
diff --git a/src/wallet/types/config.ts b/src/wallet/types/config.ts
index 272491043..1cbf8988e 100644
--- a/src/wallet/types/config.ts
+++ b/src/wallet/types/config.ts
@@ -191,9 +191,10 @@ export type MeltProofsConfig = {
   keysetId?: string;
   privkey?: string | string[];
   onCountersReserved?: OnCountersReserved;
-};
-
-export type PrepareMeltConfig = MeltProofsConfig & {
+  /**
+   * Request NUT-08 blank outputs so the mint can return unspent fee reserve. Defaults to true. Set
+   * false to forfeit the change, which also permits melting on an inactive keyset.
+   */
   nut08Change?: boolean;
 };
 
diff --git a/src/wallet/types/payment-requests.ts b/src/wallet/types/payment-requests.ts
index 266b02ef0..8bdebb0b3 100644
--- a/src/wallet/types/payment-requests.ts
+++ b/src/wallet/types/payment-requests.ts
@@ -10,7 +10,7 @@ export type RawTransport = {
 export type RawNUT10Option = {
   k: string; // kind
   d: string; // data
-  t: string[][]; // tags
+  t?: string[][]; // tags (optional per NUT-18)
 };
 
 export type RawSupportedMethod = {
@@ -73,7 +73,8 @@ export type NUT10Option = {
    */
   data: string;
   /**
-   * Tags associated with the spending condition for additional data.
+   * Optional tags associated with the spending condition for additional data. Absent and empty are
+   * equivalent: neither is encoded.
    */
-  tags: string[][];
+  tags?: string[][];
 };
diff --git a/test/wallet/WalletOps.test.ts b/test/wallet/WalletOps.test.ts
index db30d3746..be22c6940 100644
--- a/test/wallet/WalletOps.test.ts
+++ b/test/wallet/WalletOps.test.ts
@@ -380,7 +380,7 @@ describe('WalletOps builders', () => {
       const locked = new PaymentRequest({
         amount: 100,
         unit: 'sat',
-        nut10: { kind: 'P2PK', data: '02'.padEnd(66, 'a'), tags: [] },
+        nut10: { kind: 'P2PK', data: '02'.padEnd(66, 'a') },
       });
       await ops.sendToRequest(locked, proofs).run();
       const outputConfig = wallet.send.mock.calls[0][3];
@@ -389,7 +389,7 @@ describe('WalletOps builders', () => {
       const exotic = new PaymentRequest({
         amount: 100,
         unit: 'sat',
-        nut10: { kind: 'FROST', data: 'xyz', tags: [] },
+        nut10: { kind: 'FROST', data: 'xyz' },
       });
       expect(() => ops.sendToRequest(exotic, proofs)).toThrow(/nut10 lock/);
     });
diff --git a/test/wallet/paymentRequests.test.ts b/test/wallet/paymentRequests.test.ts
index 6a9d60a0a..4dda15a9d 100644
--- a/test/wallet/paymentRequests.test.ts
+++ b/test/wallet/paymentRequests.test.ts
@@ -731,7 +731,7 @@ describe('NUT-18 payment payloads', () => {
       expect(payload.mint).toBe(MINT);
       expect(payload.memo).toBe('hi');
       // BigInt-safe: an amount beyond 2^53 survives exactly.
-      expect(payload.proofs[0].amount).toBe(9007199254740993n);
+      expect(payload.proofs[0].amount.toBigInt()).toBe(9007199254740993n);
     });
 
     test('omits id and memo when absent and defaults the unit', () => {
@@ -770,9 +770,10 @@ describe('NUT-18 payment payloads', () => {
       proofs: [{ id: '009a1f293253e41e', amount: 2, secret: 's', C: '02ff' }],
     });
 
-    test('normalizes small JSON number amounts to bigint', () => {
+    test('normalizes small JSON number amounts to Amount', () => {
       const payload = PaymentRequest.decodePayload(JSON.stringify(valid()));
-      expect(payload.proofs[0].amount).toBe(2n);
+      expect(payload.proofs[0].amount).toBeInstanceOf(Amount);
+      expect(payload.proofs[0].amount.toBigInt()).toBe(2n);
     });
 
     test('preserves unknown proof fields (witness, dleq)', () => {
diff --git a/test/wallet/wallet-quotes-mutants.node.test.ts b/test/wallet/wallet-quotes-mutants.node.test.ts
index 380e3344a..fea6f51fa 100644
--- a/test/wallet/wallet-quotes-mutants.node.test.ts
+++ b/test/wallet/wallet-quotes-mutants.node.test.ts
@@ -16,7 +16,6 @@ import {
   type MintQuoteBolt12Response,
   type MeltQuoteBolt11Response,
   type MintQuoteBaseResponse,
-  type PrepareMeltConfig,
 } from '../../src';
 
 import {
@@ -170,11 +169,7 @@ describe('_prepareInputsForMint mutants', () => {
       },
     ] as unknown as Proof[];
 
-    // meltProofsBolt11 declares MeltProofsConfig but forwards the config to prepareMelt, which
-    // is what honours nut08Change.
-    await wallet.meltProofsBolt11(meltQuote, proofsToSend, {
-      nut08Change: false,
-    } as PrepareMeltConfig);
+    await wallet.meltProofsBolt11(meltQuote, proofsToSend, { nut08Change: false });
 
     expect(sentInputs).toHaveLength(1);
     expect(sentInputs[0]).not.toHaveProperty('dleq');
@@ -1069,7 +1064,7 @@ describe('createLockedMintQuote mutants', () => {
     await wallet.loadMint();
 
     const quote = await wallet.createLockedMintQuote(100, PUBKEY);
-    expect(quote.pubkey!.toLowerCase()).toBe(PUBKEY);
+    expect(quote.pubkey.toLowerCase()).toBe(PUBKEY);
   });
 
   test('rejects a missing pubkey with a clear error, not a TypeError', async () => {