add post-only support to limit order workflows

Author: cesarenaldi

packages/client/src/actions/orders.test.ts

@@ -155,6 +155,19 @@ describe('Orders', () => {
       expect(result.ok).toBe(true);
     });
 
+    it('carries post-only submission options onto the prepared order', async () => {
+      const order = await prepareLimitOrder(secureClient, {
+        orderType: OrderType.GTC,
+        postOnly: true,
+        price: minPrice,
+        side: OrderSide.BUY,
+        size: minSize,
+        tokenId: yesTokenId,
+      }).then(completeWith(walletClient));
+
+      expect(order.postOnly).toBe(true);
+    });
+
     it('requests a collateral approval if necessary', async () => {
       const gaslessClient = await publicClientWithRelayerKey
         .beginAuthentication({ wallet: safeWalletAddress })
@@ -201,13 +214,17 @@ describe('Orders', () => {
     it('creates, signs, and posts a limit order in one workflow', async () => {
       const response = await prepareLimitOrderPosting(secureClient, {
         orderType: OrderType.GTC,
+        postOnly: true,
         price: minPrice,
         side: OrderSide.BUY,
         size: minSize,
         tokenId: yesTokenId,
       }).then(completeWith(walletClient));
 
       expect(response.ok).toBe(true);
+      const acceptedResponse = expectAcceptedOrderResponse(response);
+
+      expect(acceptedResponse.status).toBe(OrderPostStatus.LIVE);
     });
   });
 

packages/client/src/actions/orders/limit.ts

@@ -34,6 +34,7 @@ export const PrepareLimitOrderParamsSchema = z
     size: z.number().positive(),
     side: OrderSideSchema,
     taker: EvmAddressSchema.optional(),
+    postOnly: z.boolean().default(false),
     expiration: z.number().int().nonnegative().optional(),
     orderType: z
       .union([z.literal(OrderType.GTC), z.literal(OrderType.GTD)])

packages/client/src/actions/orders/post.ts

@@ -3,8 +3,9 @@ import {
   OrderResponseSchema,
   type OrderResponses,
   OrderResponsesSchema,
+  OrderType,
 } from '@polymarket/bindings/clob';
-import { unwrap } from '@polymarket/types';
+import { invariant, unwrap } from '@polymarket/types';
 import { z } from 'zod';
 import type { BaseSecureClient } from '../../clients';
 import type {
@@ -108,6 +109,13 @@ export function postOrders(
 }
 
 function createSendOrderPayload(client: BaseSecureClient, order: SignedOrder) {
+  invariant(
+    order.postOnly !== true ||
+      order.orderType === OrderType.GTC ||
+      order.orderType === OrderType.GTD,
+    'Post-only orders are only supported for GTC and GTD order types.',
+  );
+
   return {
     deferExec: false,
     order: {
@@ -127,5 +135,6 @@ function createSendOrderPayload(client: BaseSecureClient, order: SignedOrder) {
     },
     orderType: order.orderType,
     owner: client.credentials.key,
+    ...(order.postOnly === true ? { postOnly: true } : {}),
   };
 }

packages/client/src/actions/orders/prepare.ts

@@ -107,6 +107,7 @@ export type PrepareLimitOrderError =
  * @example
  * ```ts
  * const order = await prepareLimitOrder(client, {
+ *   postOnly: true,
  *   price: 0.52,
  *   side: OrderSide.BUY,
  *   size: 10,
@@ -134,7 +135,9 @@ export async function prepareLimitOrder(
       yield signOrder(createOrderTypedDataPayload(unsignedOrder)),
     );
 
-    return createSignedOrder(unsignedOrder, signature);
+    const order = createSignedOrder(unsignedOrder, signature);
+
+    return params.postOnly === true ? { ...order, postOnly: true } : order;
   }.call(null);
 }
 
@@ -178,6 +181,7 @@ export type PrepareLimitOrderPostingError = PrepareLimitOrderError;
  * @example
  * ```ts
  * const response = await prepareLimitOrderPosting(client, {
+ *   postOnly: true,
  *   price: 0.52,
  *   side: OrderSide.BUY,
  *   size: 10,

packages/client/src/actions/orders/types.ts

@@ -55,6 +55,13 @@ export type PrepareLimitOrderRequest = {
   /** Taker address. Omit for public orders (zero address is equivalent). */
   taker?: string;
 
+  /**
+   * Posts the prepared order as post-only when submitted.
+   *
+   * @defaultValue false
+   */
+  postOnly?: boolean;
+
   /** Timestamp after which the order is expired. Required for GTD orders. */
   expiration?: number;
 
@@ -119,6 +126,7 @@ export type SignedOrder = {
   takerAmount: string;
   tokenId: TokenId;
   signature: EvmSignature;
+  postOnly?: boolean;
 };
 
 export type OrderWorkflowRequest =

packages/client/src/decorators/trading.ts

@@ -84,6 +84,7 @@ export type TradingActions = {
    * @example
    * ```ts
    * const order = await client.prepareLimitOrder({
+   *   postOnly: true,
    *   price: 0.52,
    *   side: OrderSide.BUY,
    *   size: 10,
@@ -105,6 +106,7 @@ export type TradingActions = {
    * @example
    * ```ts
    * const response = await client.prepareLimitOrderPosting({
+   *   postOnly: true,
    *   price: 0.52,
    *   side: OrderSide.BUY,
    *   size: 10,