lnbits migrations work

lnbits/extensions/cashu/__init__.py

@@ -9,7 +9,26 @@ from lnbits.tasks import catch_everything_and_restart
 
 db = Database("ext_cashu")
 
-cashu_ext: APIRouter = APIRouter(prefix="/cashu", tags=["cashu"])
+import sys
+
+sys.path.append("/Users/cc/git/cashu")
+from cashu.mint.ledger import Ledger
+from .crud import LedgerCrud
+
+# db = Database("ext_cashu", LNBITS_DATA_FOLDER)
+
+ledger = Ledger(
+    db=db,
+    # seed=MINT_PRIVATE_KEY,
+    seed="asd",
+    derivation_path="0/0/0/1",
+    crud=LedgerCrud,
+)
+
+cashu_ext: APIRouter = APIRouter(prefix="/api/v1/cashu", tags=["cashu"])
+# from cashu.mint.router import router as cashu_router
+
+# cashu_ext.include_router(router=cashu_router)
 
 cashu_static_files = [
     {
@@ -24,11 +43,12 @@ def cashu_renderer():
     return template_renderer(["lnbits/extensions/cashu/templates"])
 
 
-from .tasks import wait_for_paid_invoices
+from .tasks import wait_for_paid_invoices, startup_cashu_mint
 from .views import *  # noqa
 from .views_api import *  # noqa
 
 
 def cashu_start():
     loop = asyncio.get_event_loop()
+    loop.create_task(catch_everything_and_restart(startup_cashu_mint))
     loop.create_task(catch_everything_and_restart(wait_for_paid_invoices))

lnbits/extensions/cashu/config.json

@@ -1,7 +1,9 @@
 {
   "name": "Cashu Ecash",
-  "short_description": "Ecash mints with LN peg in/out",
+  "short_description": "Ecash mint and wallet",
   "icon": "approval",
   "contributors": ["arcbtc", "calle", "vlad"],
-  "hidden": false
+  "hidden": false,
+  "migration_module": "cashu.mint.migrations",
+  "db_name": "cashu"
 }

lnbits/extensions/cashu/crud.py

@@ -1,7 +1,8 @@
 import os
 import random
+import time
 from binascii import hexlify, unhexlify
-from typing import List, Optional, Union
+from typing import List, Optional, Union, Any
 
 from embit import bip32, bip39, ec, script
 from embit.networks import NETWORKS
@@ -13,6 +14,49 @@ from . import db
 from .core.base import Invoice
 from .models import Cashu, Pegs, Promises, Proof
 
+from cashu.core.base import MintKeyset
+from lnbits.db import Database, Connection
+
+
+class LedgerCrud:
+    """
+    Database interface for Cashu mint.
+
+    This class needs to be overloaded by any app that imports the Cashu mint.
+    """
+
+    async def get_keyset(*args, **kwags):
+
+        return await get_keyset(*args, **kwags)
+
+    async def get_lightning_invoice(*args, **kwags):
+
+        return await get_lightning_invoice(*args, **kwags)
+
+    async def get_proofs_used(*args, **kwags):
+
+        return await get_proofs_used(*args, **kwags)
+
+    async def invalidate_proof(*args, **kwags):
+
+        return await invalidate_proof(*args, **kwags)
+
+    async def store_keyset(*args, **kwags):
+
+        return await store_keyset(*args, **kwags)
+
+    async def store_lightning_invoice(*args, **kwags):
+
+        return await store_lightning_invoice(*args, **kwags)
+
+    async def store_promise(*args, **kwags):
+
+        return await store_promise(*args, **kwags)
+
+    async def update_lightning_invoice(*args, **kwags):
+
+        return await update_lightning_invoice(*args, **kwags)
+
 
 async def create_cashu(wallet_id: str, data: Cashu) -> Cashu:
     cashu_id = urlsafe_short_hash()
@@ -120,9 +164,15 @@ async def get_promises(cashu_id) -> Optional[Cashu]:
     return Promises(**row) if row else None
 
 
-async def get_proofs_used(cashu_id):
+async def get_proofs_used(
-    rows = await db.fetchall(
+    db: Database,
-        "SELECT secret from cashu.proofs_used WHERE cashu_id = ?", (cashu_id,)
+    conn: Optional[Connection] = None,
+):
+
+    rows = await (conn or db).fetchall(
+        """
+        SELECT secret from cashu.proofs_used
+        """
     )
     return [row[0] for row in rows]
 
@@ -184,3 +234,62 @@ async def update_lightning_invoice(cashu_id: str, hash: str, issued: bool):
             hash,
         ),
     )
+
+
+##############################
+######### KEYSETS ############
+##############################
+
+
+async def store_keyset(
+    keyset: MintKeyset,
+    db: Database = None,
+    conn: Optional[Connection] = None,
+):
+
+    await (conn or db).execute(  # type: ignore
+        """
+        INSERT INTO cashu.keysets
+          (id, derivation_path, valid_from, valid_to, first_seen, active, version)
+        VALUES (?, ?, ?, ?, ?, ?, ?)
+        """,
+        (
+            keyset.id,
+            keyset.derivation_path,
+            keyset.valid_from or db.timestamp_now,
+            keyset.valid_to or db.timestamp_now,
+            keyset.first_seen or db.timestamp_now,
+            True,
+            keyset.version,
+        ),
+    )
+
+
+async def get_keyset(
+    id: str = None,
+    derivation_path: str = "",
+    db: Database = None,
+    conn: Optional[Connection] = None,
+):
+    clauses = []
+    values: List[Any] = []
+    clauses.append("active = ?")
+    values.append(True)
+    if id:
+        clauses.append("id = ?")
+        values.append(id)
+    if derivation_path:
+        clauses.append("derivation_path = ?")
+        values.append(derivation_path)
+    where = ""
+    if clauses:
+        where = f"WHERE {' AND '.join(clauses)}"
+
+    rows = await (conn or db).fetchall(  # type: ignore
+        f"""
+        SELECT * from cashu.keysets
+        {where}
+        """,
+        tuple(values),
+    )
+    return [MintKeyset.from_row(row) for row in rows]

lnbits/extensions/cashu/migrations.py

@@ -1,79 +1 @@
-async def m001_initial(db):
+# this extension will use the migration_module module cashu.mint.migrations (see config.json)
-    """
-    Initial cashu table.
-    """
-    await db.execute(
-        """
-        CREATE TABLE cashu.cashu (
-            id TEXT PRIMARY KEY,
-            wallet TEXT NOT NULL,
-            name TEXT NOT NULL,
-            tickershort TEXT DEFAULT 'sats',
-            fraction BOOL,
-            maxsats INT,
-            coins INT,
-            prvkey TEXT NOT NULL,
-            pubkey TEXT NOT NULL
-        );
-    """
-    )
-
-    """
-    Initial cashus table.
-    """
-    await db.execute(
-        """
-        CREATE TABLE cashu.pegs (
-            id TEXT PRIMARY KEY,
-            wallet TEXT NOT NULL,
-            inout BOOL NOT NULL,
-            amount INT
-        );
-    """
-    )
-
-    """
-    Initial cashus table.
-    """
-    await db.execute(
-        """
-        CREATE TABLE cashu.promises (
-            id TEXT PRIMARY KEY,
-            amount INT,
-            B_b TEXT NOT NULL,
-            C_b TEXT NOT NULL,
-            cashu_id TEXT NOT NULL,
-            UNIQUE (B_b)
-        );
-    """
-    )
-
-    """
-    Initial cashus table.
-    """
-    await db.execute(
-        """
-        CREATE TABLE cashu.proofs_used (
-            id TEXT PRIMARY KEY,
-            amount INT,
-            C TEXT NOT NULL,
-            secret TEXT NOT NULL,
-            cashu_id TEXT NOT NULL
-        );
-    """
-    )
-
-    await db.execute(
-        """
-            CREATE TABLE IF NOT EXISTS cashu.invoices (
-                cashu_id TEXT NOT NULL,
-                amount INTEGER NOT NULL,
-                pr TEXT NOT NULL,
-                hash TEXT NOT NULL,
-                issued BOOL NOT NULL,
-
-                UNIQUE (hash)
-
-            );
-        """
-    )

lnbits/extensions/cashu/tasks.py

@@ -9,6 +9,21 @@ from lnbits.tasks import internal_invoice_queue, register_invoice_listener
 
 from .crud import get_cashu
 
+import sys
+
+sys.path.append("/Users/cc/git/cashu")
+# from cashu.mint import migrations
+# from cashu.core.migrations import migrate_databases
+from . import db, ledger
+
+
+async def startup_cashu_mint():
+    # await migrate_databases(db, migrations)
+    await ledger.load_used_proofs()
+    await ledger.init_keysets()
+    print(ledger.get_keyset())
+    pass
+
 
 async def wait_for_paid_invoices():
     invoice_queue = asyncio.Queue()

lnbits/extensions/cashu/templates/cashu/index.html

@@ -120,7 +120,7 @@
           emit-value
           v-model="formDialog.data.wallet"
           :options="g.user.walletOptions"
-          label="Wallet *"
+          label="Cashu wallet *"
         ></q-select>
         <q-toggle
           v-model="toggleAdvanced"
@@ -156,7 +156,7 @@
                 dense
                 v-model.trim="formDialog.data.tickershort"
                 label="Ticker shorthand"
-                placeholder="CC"
+                placeholder="sats"
                 #
               ></q-input>
             </div>
@@ -229,7 +229,7 @@
             {
               name: 'wallet',
               align: 'left',
-              label: 'Wallet',
+              label: 'Cashu wallet',
               field: 'wallet'
             },
             {

lnbits/extensions/cashu/templates/cashu/wallet.html

@@ -1,5 +1,5 @@
-{% extends "public.html" %} {% block toolbar_title %} {% raw %} {{name}} Wallet
+{% extends "public.html" %} {% block toolbar_title %} {% raw %} {{name}} Cashu
-{% endraw %} {% endblock %} {% block footer %}{% endblock %} {% block
+wallet {% endraw %} {% endblock %} {% block footer %}{% endblock %} {% block
 page_container %}
 <q-page-container>
   <q-page>
@@ -14,9 +14,8 @@ page_container %}
                   rounded
                   color="secondary"
                   class="full-width"
-                  @click="showBuyTokensDialog"
+                  @click="showInvoicesDialog"
-                  >Buy tokens
+                  >Create invoice
-                  <h5 class="text-caption q-ml-sm q-mb-none">(with sats)</h5>
                 </q-btn>
               </div>
               <div class="col-6">
@@ -34,8 +33,7 @@ page_container %}
                   rounded
                   color="secondary"
                   class="full-width"
-                  >Sell tokens
+                  >Pay invoice
-                  <h5 class="text-caption q-ml-sm q-mb-none">(for sats)</h5>
                 </q-btn>
               </div>
             </div>
@@ -115,11 +113,11 @@ page_container %}
                 <q-table
                   dense
                   flat
-                  :data="buyOrders"
+                  :data="invoicesCashu"
-                  :columns="buysTable.columns"
+                  :columns="invoicesTable.columns"
-                  :pagination.sync="buysTable.pagination"
+                  :pagination.sync="invoicesTable.pagination"
-                  no-data-label="No buys made yet"
+                  no-data-label="No invoices made yet"
-                  :filter="buysTable.filter"
+                  :filter="invoicesTable.filter"
                 >
                   {% raw %}
                   <template v-slot:body="props">
@@ -137,7 +135,7 @@ page_container %}
                             size="lg"
                             color="secondary"
                             class="q-mr-md cursor-pointer"
-                            @click="recheckBuyOrder(props.row.hash)"
+                            @click="recheckInvoice(props.row.hash)"
                           >
                             Recheck
                           </q-badge>
@@ -182,11 +180,15 @@ page_container %}
         active-class="px-0"
         indicator-color="transparent"
       >
-        <q-tab icon="arrow_right" label="Buy" @click="showBuyTokensDialog">
+        <q-tab
+          icon="arrow_right"
+          label="Create Invoice"
+          @click="showInvoicesDialog"
+        >
         </q-tab>
-        <q-tab icon="arrow_downward" label="Receive"></q-tab>
+        <q-tab icon="arrow_downward" label="Receive Tokens"></q-tab>
-        <q-tab icon="arrow_upward" label="Send"></q-tab>
+        <q-tab icon="arrow_upward" label="Send Token"></q-tab>
-        <q-tab icon="arrow_right" label="Sell"> </q-tab>
+        <q-tab icon="arrow_right" label="Pay Invoice"> </q-tab>
       </q-tabs>
 
       <q-dialog v-model="disclaimerDialog.show">
@@ -214,7 +216,7 @@ page_container %}
 
       <q-dialog v-model="showInvoiceDetails" position="top">
         <q-card class="q-pa-lg q-pt-xl lnbits__dialog-card">
-          <div v-if="!buyData.bolt11">
+          <div v-if="!invoiceData.bolt11">
             <div class="row items-center no-wrap q-mb-sm">
               <div class="col-12">
                 <span class="text-subtitle1"
@@ -225,7 +227,7 @@ page_container %}
             <q-input
               filled
               dense
-              v-model.number="buyData.amount"
+              v-model.number="invoiceData.amount"
               label="Amount (sats) *"
               type="number"
               class="q-mb-lg"
@@ -234,15 +236,15 @@ page_container %}
             <q-input
               filled
               dense
-              v-model.trim="buyData.memo"
+              v-model.trim="invoiceData.memo"
               label="Memo"
             ></q-input>
           </div>
           <div v-else class="text-center q-mb-lg">
-            <a :href="'lightning:' + buyData.bolt11">
+            <a :href="'lightning:' + invoiceData.bolt11">
               <q-responsive :ratio="1" class="q-mx-xl">
                 <qrcode
-                  :value="buyData.bolt11"
+                  :value="invoiceData.bolt11"
                   :options="{width: 340}"
                   class="rounded-borders"
                 >
@@ -252,8 +254,8 @@ page_container %}
           </div>
           <div class="row q-mt-lg">
             <q-btn
-              v-if="buyData.bolt11"
+              v-if="invoiceData.bolt11"
-              @click="copyText(buyData.bolt11)"
+              @click="copyText(invoiceData.bolt11)"
               outline
               color="grey"
               >Copy invoice</q-btn
@@ -449,8 +451,8 @@ page_container %}
         mintId: '',
         mintName: '',
         keys: '',
-        buyOrders: [],
+        invoicesCashu: [],
-        buyData: {
+        invoiceData: {
           amount: 0,
           memo: '',
           bolt11: '',
@@ -507,7 +509,7 @@ page_container %}
           }
         },
         payments: [],
-        buysTable: {
+        invoicesTable: {
           columns: [
             {
               name: 'status',
@@ -873,17 +875,17 @@ page_container %}
       },
 
       /////////////////////////////////// WALLET ///////////////////////////////////
-      showBuyTokensDialog: async function () {
+      showInvoicesDialog: async function () {
-        console.log('##### showBuyTokensDialog')
+        console.log('##### showInvoicesDialog')
-        this.buyData.amount = 0
+        this.invoiceData.amount = 0
-        this.buyData.bolt11 = ''
+        this.invoiceData.bolt11 = ''
-        this.buyData.hash = ''
+        this.invoiceData.hash = ''
-        this.buyData.memo = ''
+        this.invoiceData.memo = ''
         this.showInvoiceDetails = true
       },
 
       showInvoiceDialog: function (data) {
-        this.buyData = _.clone(data)
+        this.invoiceData = _.clone(data)
         this.showInvoiceDetails = true
       },
 
@@ -911,20 +913,20 @@ page_container %}
         try {
           const {data} = await LNbits.api.request(
             'GET',
-            `/cashu/api/v1/cashu/${this.mintId}/mint?amount=${this.buyData.amount}`
+            `/cashu/api/v1/cashu/${this.mintId}/mint?amount=${this.invoiceData.amount}`
           )
           console.log('### data', data)
 
-          this.buyData.bolt11 = data.pr
+          this.invoiceData.bolt11 = data.pr
-          this.buyData.hash = data.hash
+          this.invoiceData.hash = data.hash
-          this.buyOrders.push({
+          this.invoicesCashu.push({
-            ..._.clone(this.buyData),
+            ..._.clone(this.invoiceData),
             date: currentDateStr(),
             status: 'pending'
           })
-          this.storeBuyOrders()
+          this.storeinvoicesCashu()
-          const amounts = splitAmount(this.buyData.amount)
+          const amounts = splitAmount(this.invoiceData.amount)
-          await this.requestTokens(amounts, this.buyData.hash)
+          await this.requestTokens(amounts, this.invoiceData.hash)
           this.tab = 'orders'
         } catch (error) {
           console.error(error)
@@ -933,12 +935,12 @@ page_container %}
       },
 
       checkXXXXXX: async function () {
-        for (const tokenBuy of this.buyOrders) {
+        for (const invoice of this.invoicesCashu) {
-          if (tokenBuy.status === 'pending') {
+          if (invoice.status === 'pending') {
             try {
               const {data} = await LNbits.api.request(
                 'POST',
-                `/cashu/api/v1/cashu/${this.mintId}/mint?payment_hash=${tokenBuy.hash}`,
+                `/cashu/api/v1/cashu/${this.mintId}/mint?payment_hash=${invoice.hash}`,
                 '',
                 {
                   blinded_messages: []
@@ -953,10 +955,10 @@ page_container %}
         }
       },
 
-      recheckBuyOrder: async function (hash) {
+      recheckInvoice: async function (hash) {
-        console.log('### recheckBuyOrder.hash', hash)
+        console.log('### recheckInvoice.hash', hash)
         const tokens = this.tokens.find(bt => bt.hash === hash)
-        console.log('### recheckBuyOrder.tokens', tokens)
+        console.log('### recheckInvoice.tokens', tokens)
         if (!tokens) {
           console.error('####### no token for hash', hash)
           return
@@ -970,9 +972,9 @@ page_container %}
           tokens.status = 'paid'
           this.storeTokens()
 
-          const buyOrder = this.buyOrders.find(bo => bo.hash === hash)
+          const invoice = this.invoicesCashu.find(bo => bo.hash === hash)
-          buyOrder.status = 'paid'
+          invoice.status = 'paid'
-          this.storeBuyOrders()
+          this.storeinvoicesCashu()
         }
       },
 
@@ -1261,8 +1263,11 @@ page_container %}
         localStorage.setItem('cashu.keys', JSON.stringify(data))
       },
 
-      storeBuyOrders: function () {
+      storeinvoicesCashu: function () {
-        localStorage.setItem('cashu.buyOrders', JSON.stringify(this.buyOrders))
+        localStorage.setItem(
+          'cashu.invoicesCashu',
+          JSON.stringify(this.invoicesCashu)
+        )
       },
       storeTokens: function () {
         localStorage.setItem(
@@ -1285,8 +1290,8 @@ page_container %}
         !params.get('tsh') &&
         !this.$q.localStorage.getItem('cashu.tickershort')
       ) {
-        this.$q.localStorage.set('cashu.tickershort', 'CE')
+        this.$q.localStorage.set('cashu.tickershort', 'sats')
-        this.tickershort = 'CE'
+        this.tickershort = 'sats'
       } else if (params.get('tsh')) {
         this.$q.localStorage.set('cashu.tickershort', params.get('tsh'))
         this.tickershort = params.get('tsh')
@@ -1322,11 +1327,11 @@ page_container %}
         this.keys = JSON.parse(keysJson)
       }
 
-      this.buyOrders = JSON.parse(
+      this.invoicesCashu = JSON.parse(
-        localStorage.getItem('cashu.buyOrders') || '[]'
+        localStorage.getItem('cashu.invoicesCashu') || '[]'
       )
       this.tokens = JSON.parse(localStorage.getItem('cashu.tokens') || '[]')
-      console.log('### buyOrders', this.buyOrders)
+      console.log('### invoicesCashu', this.invoicesCashu)
       console.table('### tokens', this.tokens)
       console.log('#### this.mintId', this.mintId)
       console.log('#### this.mintName', this.mintName)

lnbits/extensions/cashu/views_api.py

@@ -28,7 +28,8 @@ from .crud import (
     store_promise,
     update_lightning_invoice,
 )
-from .ledger import mint, request_mint
+
+# from .ledger import mint, request_mint
 from .mint import generate_promises, get_pubkeys, melt, split
 from .models import (
     Cashu,
@@ -207,15 +208,15 @@ async def api_cashu_check_invoice(cashu_id: str, payment_hash: str):
 ########################################
 
 
-@cashu_ext.get("/api/v1/cashu/{cashu_id}/keys", status_code=HTTPStatus.OK)
+# @cashu_ext.get("/api/v1/cashu/{cashu_id}/keys", status_code=HTTPStatus.OK)
-async def keys(cashu_id: str = Query(False)):
+# async def keys(cashu_id: str = Query(False)):
-    """Get the public keys of the mint"""
+#     """Get the public keys of the mint"""
-    mint = await get_cashu(cashu_id)
+#     mint = await get_cashu(cashu_id)
-    if mint is None:
+#     if mint is None:
-        raise HTTPException(
+#         raise HTTPException(
-            status_code=HTTPStatus.NOT_FOUND, detail="Mint does not exist."
+#             status_code=HTTPStatus.NOT_FOUND, detail="Mint does not exist."
-        )
+#         )
-    return get_pubkeys(mint.prvkey)
+#     return get_pubkeys(mint.prvkey)
 
 
 @cashu_ext.get("/api/v1/cashu/{cashu_id}/mint")
@@ -355,3 +356,129 @@ async def split_proofs(payload: SplitRequest, cashu_id: str = Query(None)):
     resp = PostSplitResponse(fst=frst_promises, snd=scnd_promises)
     print("### resp", json.dumps(resp, default=vars))
     return resp
+
+
+##################################################################
+##################################################################
+# CASHU LIB
+##################################################################
+
+from typing import Dict, List, Union
+
+from fastapi import APIRouter
+from secp256k1 import PublicKey
+
+from cashu.core.base import (
+    BlindedSignature,
+    CheckFeesRequest,
+    CheckFeesResponse,
+    CheckRequest,
+    GetMeltResponse,
+    GetMintResponse,
+    MeltRequest,
+    MintRequest,
+    PostSplitResponse,
+    SplitRequest,
+)
+from cashu.core.errors import CashuError
+
+from . import db, ledger
+
+
+@cashu_ext.get("/keys")
+async def keys() -> dict[int, str]:
+    """Get the public keys of the mint"""
+    return ledger.get_keyset()
+
+
+@cashu_ext.get("/keysets")
+async def keysets() -> dict[str, list[str]]:
+    """Get all active keysets of the mint"""
+    return {"keysets": await ledger.keysets.get_ids()}
+
+
+@cashu_ext.get("/mint")
+async def request_mint(amount: int = 0) -> GetMintResponse:
+    """
+    Request minting of new tokens. The mint responds with a Lightning invoice.
+    This endpoint can be used for a Lightning invoice UX flow.
+
+    Call `POST /mint` after paying the invoice.
+    """
+    payment_request, payment_hash = await ledger.request_mint(amount)
+    print(f"Lightning invoice: {payment_request}")
+    resp = GetMintResponse(pr=payment_request, hash=payment_hash)
+    return resp
+
+
+@cashu_ext.post("/mint")
+async def mint(
+    payloads: MintRequest,
+    payment_hash: Union[str, None] = None,
+) -> Union[List[BlindedSignature], CashuError]:
+    """
+    Requests the minting of tokens belonging to a paid payment request.
+
+    Call this endpoint after `GET /mint`.
+    """
+    amounts = []
+    B_s = []
+    for payload in payloads.blinded_messages:
+        amounts.append(payload.amount)
+        B_s.append(PublicKey(bytes.fromhex(payload.B_), raw=True))
+    try:
+        promises = await ledger.mint(B_s, amounts, payment_hash=payment_hash)
+        return promises
+    except Exception as exc:
+        return CashuError(error=str(exc))
+
+
+@cashu_ext.post("/melt")
+async def melt(payload: MeltRequest) -> GetMeltResponse:
+    """
+    Requests tokens to be destroyed and sent out via Lightning.
+    """
+    ok, preimage = await ledger.melt(payload.proofs, payload.invoice)
+    resp = GetMeltResponse(paid=ok, preimage=preimage)
+    return resp
+
+
+@cashu_ext.post("/check")
+async def check_spendable(payload: CheckRequest) -> Dict[int, bool]:
+    """Check whether a secret has been spent already or not."""
+    return await ledger.check_spendable(payload.proofs)
+
+
+@cashu_ext.post("/checkfees")
+async def check_fees(payload: CheckFeesRequest) -> CheckFeesResponse:
+    """
+    Responds with the fees necessary to pay a Lightning invoice.
+    Used by wallets for figuring out the fees they need to supply.
+    This is can be useful for checking whether an invoice is internal (Cashu-to-Cashu).
+    """
+    fees_msat = await ledger.check_fees(payload.pr)
+    return CheckFeesResponse(fee=fees_msat / 1000)
+
+
+@cashu_ext.post("/split")
+async def split(
+    payload: SplitRequest,
+) -> Union[CashuError, PostSplitResponse]:
+    """
+    Requetst a set of tokens with amount "total" to be split into two
+    newly minted sets with amount "split" and "total-split".
+    """
+    proofs = payload.proofs
+    amount = payload.amount
+    outputs = payload.outputs.blinded_messages if payload.outputs else None
+    # backwards compatibility with clients < v0.2.2
+    assert outputs, Exception("no outputs provided.")
+    try:
+        split_return = await ledger.split(proofs, amount, outputs)
+    except Exception as exc:
+        return CashuError(error=str(exc))
+    if not split_return:
+        return CashuError(error="there was an error with the split")
+    frst_promises, scnd_promises = split_return
+    resp = PostSplitResponse(fst=frst_promises, snd=scnd_promises)
+    return resp