diff --git a/src/client/api/deposit.ts b/src/client/api/deposit.ts
index 4281e52d..23ffe251 100644
--- a/src/client/api/deposit.ts
+++ b/src/client/api/deposit.ts
@@ -1,17 +1,23 @@
 
-import { EscrowClient }          from '../class/client.js'
-import { validate_account_req, validate_register_req } from '@/validators/index.js'
+import { EscrowClient } from '../class/client.js'
+
+import {
+  validate_account_req,
+  validate_covenant,
+  validate_register_req,
+  validate_spend_req
+} from '@/validators/index.js'
 
 import {
   CovenantData,
-  ReturnData,
   ApiResponse,
   AccountRequest,
   AccountDataResponse,
   DepositDataResponse,
   DepositListResponse,
   FundingDataResponse,
-  RegisterRequest
+  RegisterRequest,
+  SpendRequest
 } from '@/types/index.js'
 
 import * as assert from '@/assert.js'
@@ -104,6 +110,8 @@ function list_deposit_api (client : EscrowClient) {
     pubkey : string,
     token  : string
   ) : Promise<ApiResponse<DepositListResponse>> => {
+    // Validate the pubkey.
+    assert.is_hash(pubkey)
     // Formulate the request.
     const url = `${client.host}/api/deposit/list/${pubkey}`
     // Return the response.
@@ -116,26 +124,32 @@ function commit_funds_api (client : EscrowClient) {
     dpid     : string,
     covenant : CovenantData
   ) : Promise<ApiResponse<FundingDataResponse>> => {
+    // Validate the deposit id.
+    assert.is_hash(dpid)
+    // Validate the covenant.
+    validate_covenant(covenant)
+    // Create the request url.
     const url    = `${client.host}/api/deposit/${dpid}/commit`
-    const body   = JSON.stringify(covenant)
+    // Create the request object.
     const init   = {
-      body,
+      body    : JSON.stringify(covenant),
       method  : 'POST',
       headers : { 'content-type' : 'application/json' }
     }
+    // Fetch and return a response.
     return client.fetcher<FundingDataResponse>({ url, init })
   }
 }
 
 function close_deposit_api (client : EscrowClient) {
   return async (
-    req : ReturnData
+    dpid : string,
+    req  : SpendRequest
   ) : Promise<ApiResponse<DepositDataResponse>> => {
-    const dpid = req.dpid
+    validate_spend_req(req)
     const url  = `${client._host}/api/deposit/${dpid}/close`
-    const body = JSON.stringify(req)
     const init = {
-      body,
+      body    : JSON.stringify(req),
       headers : { 'content-type': 'application/json' },
       method  : 'POST'
     }
diff --git a/src/lib/deposit.ts b/src/lib/deposit.ts
index bab3b4ab..1b2ce557 100644
--- a/src/lib/deposit.ts
+++ b/src/lib/deposit.ts
@@ -1,5 +1,7 @@
-import { get_return_script } from './return.js'
+import { parse_extkey }      from '@cmdcode/crypto-tools/hd'
 import { validate_deposit }  from '@/validators/deposit.js'
+import { get_return_script } from './return.js'
+import { RETURN_TX_VSIZE }   from '@/config.js'
 
 import {
   get_object_id,
@@ -12,6 +14,7 @@ import {
 } from '@cmdcode/musig2'
 
 import {
+  create_tx_template,
   get_address,
   get_tapkey,
   parse_timelock
@@ -160,3 +163,22 @@ export function get_spend_state (
   // Return the spend state.
   return state
 }
+
+export function get_ext_pubkey (xpub : string) {
+  return parse_extkey(xpub).pubkey
+}
+
+export function get_close_tx_template (
+  value   : number,
+  xpub    : string,
+  feerate : number
+) {
+  // Parse the return pubkey.
+  const return_pk = get_ext_pubkey(xpub)
+  // Create locking script.
+  const script  = [ 'OP_1', return_pk ]
+  // Calculate the transaction fee.
+  const txfee = Math.ceil(RETURN_TX_VSIZE * feerate)
+  // Return a transaction using the provided params.
+  return create_tx_template(script, value - txfee)
+}
diff --git a/src/schema/deposit.ts b/src/schema/deposit.ts
index 67bc6f52..068d2112 100644
--- a/src/schema/deposit.ts
+++ b/src/schema/deposit.ts
@@ -58,6 +58,12 @@ const reg_req = z.object({
   utxo        : txspend
 })
 
+const spend_req = z.object({
+  pnonce : nonce,
+  psig   : hex,
+  txfee  : num
+})
+
 const data = z.object({
   status,
   agent_id    : hash,
@@ -73,4 +79,4 @@ const data = z.object({
   updated_at  : stamp
 }).and(state).and(spend_state).and(close_state).and(txspend)
 
-export default { account, covenant, data, state, acct_req, reg_req, status }
+export default { account, covenant, data, state, acct_req, reg_req, spend_req, status }
diff --git a/src/types/deposit.ts b/src/types/deposit.ts
index b1362465..dbba5d47 100644
--- a/src/types/deposit.ts
+++ b/src/types/deposit.ts
@@ -101,6 +101,12 @@ export interface RegisterRequest {
   utxo         : TxOutput
 }
 
+export interface SpendRequest {
+  feerate : number
+  pnonce  : string
+  psig    : string
+}
+
 export interface ExtendedKey {
   prefix : number
   depth  : number
diff --git a/src/validators/covenant.ts b/src/validators/covenant.ts
index 1c542a9d..58551947 100644
--- a/src/validators/covenant.ts
+++ b/src/validators/covenant.ts
@@ -3,6 +3,8 @@ import { parse_txout }    from '@/lib/tx.js'
 import { parse_covenant } from '@/lib/parse.js'
 import { get_entry }      from '../lib/util.js'
 
+import { get_close_tx_template } from '@/lib/deposit.js'
+
 import {
   get_path_mutexes,
   get_return_mutex,
@@ -15,9 +17,9 @@ import {
   CovenantData,
   DepositContext,
   DepositData,
-  ReturnData,
   MutexEntry,
-  SignerAPI
+  SignerAPI,
+  SpendRequest
 } from '../types/index.js'
 
 import * as assert from '../assert.js'
@@ -52,16 +54,16 @@ export function verify_covenant (
   check_deposit_psigs(entries, covenant.psigs)
 }
 
-export function verify_refund (
+export function verify_spend_req (
   dp_agent : SignerAPI,
   deposit  : DepositData,
-  refund   : ReturnData
+  request  : SpendRequest
 ) {
-  const { dpid, agent_pn } = deposit
-  const { pnonce, psig, txhex } = refund
-  assert.ok(dpid === refund.dpid, 'deposit_id does not match')
+  const { agent_pn, spend_xpub, value } = deposit
+  const { feerate, pnonce, psig } = request
   check_deposit_agent(dp_agent, deposit)
   const pnonces = [ pnonce, agent_pn ]
+  const txhex   = get_close_tx_template(value, spend_xpub, feerate)
   const mutex   = get_return_mutex(deposit, pnonces, txhex)
   verify_mutex_psig(mutex, psig)
 }
diff --git a/src/validators/deposit.ts b/src/validators/deposit.ts
index 6be4a2e6..aa134ef2 100644
--- a/src/validators/deposit.ts
+++ b/src/validators/deposit.ts
@@ -5,6 +5,7 @@ import {
   DepositContext,
   DepositData,
   RegisterRequest,
+  SpendRequest,
   TxOutput
 } from '../types/index.js'
 
@@ -23,6 +24,12 @@ export function validate_register_req (
   schema.deposit.reg_req.parse(template)
 }
 
+export function validate_spend_req (
+  template : unknown
+) : asserts template is SpendRequest {
+  schema.deposit.spend_req.parse(template)
+}
+
 export function validate_deposit (
   deposit : Record<string, any>
 ) : asserts deposit is DepositData {