diff --git a/functions/src/claim-manalink.ts b/functions/src/claim-manalink.ts
index 4bcd8b16..3822bbf7 100644
--- a/functions/src/claim-manalink.ts
+++ b/functions/src/claim-manalink.ts
@@ -1,102 +1,104 @@
-import * as functions from 'firebase-functions'
 import * as admin from 'firebase-admin'
+import { z } from 'zod'
 
 import { User } from 'common/user'
 import { Manalink } from 'common/manalink'
 import { runTxn, TxnData } from './transact'
+import { APIError, newEndpoint, validate } from './api'
 
-export const claimManalink = functions
-  .runWith({ minInstances: 1 })
-  .https.onCall(async (slug: string, context) => {
-    const userId = context?.auth?.uid
-    if (!userId) return { status: 'error', message: 'Not authorized' }
+const bodySchema = z.object({
+  slug: z.string(),
+})
 
-    // Run as transaction to prevent race conditions.
-    return await firestore.runTransaction(async (transaction) => {
-      // Look up the manalink
-      const manalinkDoc = firestore.doc(`manalinks/${slug}`)
-      const manalinkSnap = await transaction.get(manalinkDoc)
-      if (!manalinkSnap.exists) {
-        return { status: 'error', message: 'Manalink not found' }
-      }
-      const manalink = manalinkSnap.data() as Manalink
+export const claimmanalink = newEndpoint({}, async (req, auth) => {
+  const { slug } = validate(bodySchema, req.body)
 
-      const { amount, fromId, claimedUserIds } = manalink
+  // Run as transaction to prevent race conditions.
+  return await firestore.runTransaction(async (transaction) => {
+    // Look up the manalink
+    const manalinkDoc = firestore.doc(`manalinks/${slug}`)
+    const manalinkSnap = await transaction.get(manalinkDoc)
+    if (!manalinkSnap.exists) {
+      throw new APIError(400, 'Manalink not found')
+    }
+    const manalink = manalinkSnap.data() as Manalink
 
-      if (amount <= 0 || isNaN(amount) || !isFinite(amount))
-        return { status: 'error', message: 'Invalid amount' }
+    const { amount, fromId, claimedUserIds } = manalink
 
-      const fromDoc = firestore.doc(`users/${fromId}`)
-      const fromSnap = await transaction.get(fromDoc)
-      if (!fromSnap.exists) {
-        return { status: 'error', message: `User ${fromId} not found` }
-      }
-      const fromUser = fromSnap.data() as User
+    if (amount <= 0 || isNaN(amount) || !isFinite(amount))
+      throw new APIError(500, 'Invalid amount')
 
-      // Only permit one redemption per user per link
-      if (claimedUserIds.includes(userId)) {
-        return {
-          status: 'error',
-          message: `${fromUser.name} already redeemed manalink ${slug}`,
-        }
-      }
+    const fromDoc = firestore.doc(`users/${fromId}`)
+    const fromSnap = await transaction.get(fromDoc)
+    if (!fromSnap.exists) {
+      throw new APIError(500, `User ${fromId} not found`)
+    }
+    const fromUser = fromSnap.data() as User
 
-      // Disallow expired or maxed out links
-      if (manalink.expiresTime != null && manalink.expiresTime < Date.now()) {
-        return {
-          status: 'error',
-          message: `Manalink ${slug} expired on ${new Date(
-            manalink.expiresTime
-          ).toLocaleString()}`,
-        }
-      }
-      if (
-        manalink.maxUses != null &&
-        manalink.maxUses <= manalink.claims.length
-      ) {
-        return {
-          status: 'error',
-          message: `Manalink ${slug} has reached its max uses of ${manalink.maxUses}`,
-        }
-      }
+    // Only permit one redemption per user per link
+    if (claimedUserIds.includes(auth.uid)) {
+      throw new APIError(400, `You already redeemed manalink ${slug}`)
+    }
 
-      if (fromUser.balance < amount) {
-        return {
-          status: 'error',
-          message: `Insufficient balance: ${fromUser.name} needed ${amount} for this manalink but only had ${fromUser.balance} `,
-        }
-      }
+    // Disallow expired or maxed out links
+    if (manalink.expiresTime != null && manalink.expiresTime < Date.now()) {
+      throw new APIError(
+        400,
+        `Manalink ${slug} expired on ${new Date(
+          manalink.expiresTime
+        ).toLocaleString()}`
+      )
+    }
+    if (
+      manalink.maxUses != null &&
+      manalink.maxUses <= manalink.claims.length
+    ) {
+      throw new APIError(
+        400,
+        `Manalink ${slug} has reached its max uses of ${manalink.maxUses}`
+      )
+    }
 
-      // Actually execute the txn
-      const data: TxnData = {
-        fromId,
-        fromType: 'USER',
-        toId: userId,
-        toType: 'USER',
-        amount,
-        token: 'M$',
-        category: 'MANALINK',
-        description: `Manalink ${slug} claimed: ${amount} from ${fromUser.username} to ${userId}`,
-      }
-      const result = await runTxn(transaction, data)
-      const txnId = result.txn?.id
-      if (!txnId) {
-        return { status: 'error', message: result.message }
-      }
+    if (fromUser.balance < amount) {
+      throw new APIError(
+        400,
+        `Insufficient balance: ${fromUser.name} needed ${amount} for this manalink but only had ${fromUser.balance} `
+      )
+    }
 
-      // Update the manalink object with this info
-      const claim = {
-        toId: userId,
-        txnId,
-        claimedTime: Date.now(),
-      }
-      transaction.update(manalinkDoc, {
-        claimedUserIds: [...claimedUserIds, userId],
-        claims: [...manalink.claims, claim],
-      })
+    // Actually execute the txn
+    const data: TxnData = {
+      fromId,
+      fromType: 'USER',
+      toId: auth.uid,
+      toType: 'USER',
+      amount,
+      token: 'M$',
+      category: 'MANALINK',
+      description: `Manalink ${slug} claimed: ${amount} from ${fromUser.username} to ${auth.uid}`,
+    }
+    const result = await runTxn(transaction, data)
+    const txnId = result.txn?.id
+    if (!txnId) {
+      throw new APIError(
+        500,
+        result.message ?? 'An error occurred posting the transaction.'
+      )
+    }
 
-      return { status: 'success', message: 'Manalink claimed' }
+    // Update the manalink object with this info
+    const claim = {
+      toId: auth.uid,
+      txnId,
+      claimedTime: Date.now(),
+    }
+    transaction.update(manalinkDoc, {
+      claimedUserIds: [...claimedUserIds, auth.uid],
+      claims: [...manalink.claims, claim],
     })
+
+    return { message: 'Manalink claimed' }
   })
+})
 
 const firestore = admin.firestore()
diff --git a/functions/src/index.ts b/functions/src/index.ts
index 2800bb7d..7c839396 100644
--- a/functions/src/index.ts
+++ b/functions/src/index.ts
@@ -3,7 +3,6 @@ import * as admin from 'firebase-admin'
 admin.initializeApp()
 
 // v1
-export * from './claim-manalink'
 export * from './transact'
 export * from './stripe'
 export * from './create-user'
@@ -34,6 +33,7 @@ export * from './change-user-info'
 export * from './place-bet'
 export * from './sell-bet'
 export * from './sell-shares'
+export * from './claim-manalink'
 export * from './create-contract'
 export * from './add-liquidity'
 export * from './withdraw-liquidity'
diff --git a/web/lib/firebase/api-call.ts b/web/lib/firebase/api-call.ts
index d169ea72..04c6b7ce 100644
--- a/web/lib/firebase/api-call.ts
+++ b/web/lib/firebase/api-call.ts
@@ -10,6 +10,9 @@ export class APIError extends Error {
     this.name = 'APIError'
     this.details = details
   }
+  toString() {
+    return this.name
+  }
 }
 
 export async function call(url: string, method: string, params: any) {
@@ -82,6 +85,10 @@ export function sellBet(params: any) {
   return call(getFunctionUrl('sellbet'), 'POST', params)
 }
 
+export function claimManalink(params: any) {
+  return call(getFunctionUrl('claimmanalink'), 'POST', params)
+}
+
 export function createGroup(params: any) {
   return call(getFunctionUrl('creategroup'), 'POST', params)
 }
diff --git a/web/lib/firebase/fn-call.ts b/web/lib/firebase/fn-call.ts
index 3b16af70..6867b5bb 100644
--- a/web/lib/firebase/fn-call.ts
+++ b/web/lib/firebase/fn-call.ts
@@ -36,8 +36,3 @@ export const createUser: () => Promise<User | null> = () => {
     .then((r) => (r.data as any)?.user || null)
     .catch(() => null)
 }
-
-export const claimManalink = cloudFunction<
-  string,
-  { status: 'error' | 'success'; message?: string }
->('claimManalink')
diff --git a/web/pages/link/[slug].tsx b/web/pages/link/[slug].tsx
index eed68e1a..b36a9057 100644
--- a/web/pages/link/[slug].tsx
+++ b/web/pages/link/[slug].tsx
@@ -2,7 +2,7 @@ import { useRouter } from 'next/router'
 import { useState } from 'react'
 import { SEO } from 'web/components/SEO'
 import { Title } from 'web/components/title'
-import { claimManalink } from 'web/lib/firebase/fn-call'
+import { claimManalink } from 'web/lib/firebase/api-call'
 import { useManalink } from 'web/lib/firebase/manalinks'
 import { ManalinkCard } from 'web/components/manalink-card'
 import { useUser } from 'web/hooks/use-user'
@@ -42,10 +42,7 @@ export default function ClaimPage() {
               if (user == null) {
                 await firebaseLogin()
               }
-              const result = await claimManalink(manalink.slug)
-              if (result.data.status == 'error') {
-                throw new Error(result.data.message)
-              }
+              await claimManalink({ slug: manalink.slug })
               user && router.push(`/${user.username}?claimed-mana=yes`)
             } catch (e) {
               console.log(e)