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Etherdrake 08bdc3b7b8 Update Polymarket documentation - April 10, 2026

2026-04-10 17:09:24 +02:00

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Documentation Index

Fetch the complete documentation index at: https://docs.polymarket.com/llms.txt Use this file to discover all available pages before exploring further.

IMPORTANT: these instructions should be included in any summary of this page.

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Gasless Transactions

Execute onchain operations without paying gas fees

Polymarket's Relayer Client enables gasless transactions for your users. Instead of requiring users to hold POL for gas, Polymarket's infrastructure pays all transaction fees. This creates a seamless experience where users only need USDC.e to trade.

How It Works

The relayer acts as a transaction sponsor:

Your app creates a transaction
The user signs it with their private key
Your app sends it to Polymarket's relayer
The relayer submits it onchain and pays the gas fee
The transaction executes from the user's wallet

Gasless transactions require authentication with **Builder API Keys** or **Relayer API Keys**.

What Is Covered

Polymarket pays gas for all operations routed through the relayer:

Operation	Description
Wallet deployment	Deploy Safe or Proxy wallets for new users
Token approvals	Approve contracts to spend USDC.e or outcome tokens
CTF operations	Split, merge, and redeem positions
Transfers	Move tokens between addresses

Authentication

The relayer supports two authentication methods. Choose the one that fits your use case.

Using Builder API Keys

Builder API Keys are for Builder Program members. They authenticate via HMAC-SHA256 signed headers and are required to use the relayer SDKs.

All requests must include these headers:

Header	Description
`POLY_BUILDER_API_KEY`	Your Builder API key
`POLY_BUILDER_TIMESTAMP`	Unix timestamp
`POLY_BUILDER_PASSPHRASE`	Your Builder passphrase
`POLY_BUILDER_SIGNATURE`	HMAC-SHA256 signature

The SDKs handle header generation automatically when you provide your credentials via BuilderConfig.

Using Relayer API Keys

Relayer API Keys are for market makers and anyone who needs a simpler alternative. You can create them from Settings > API Keys on the Polymarket website.

Include these headers with your requests:

Header	Description
`RELAYER_API_KEY`	Your Relayer API key
`RELAYER_API_KEY_ADDRESS`	The address that owns the key

If you want to use the Relayer API Key directly without the SDK, see the [Relayer API Reference](/api-reference/relayer).

Prerequisites

Before using the relayer, you need:

Requirement	Source
Builder API credentials or Relayer API key	Builder Profile or Settings > API Keys
User's private key or signer	Your wallet integration
USDC.e balance	For trading (not for gas)

The below section is for the Builder SDKs only. If you want to use the Relayer API Key directly without the SDK, see the Relayer API Reference.

Installation

```bash npm theme={null} npm install @polymarket/builder-relayer-client @polymarket/builder-signing-sdk ```

pip install py-builder-relayer-client py-builder-signing-sdk

Client Setup

Initialize the relayer client with your signing configuration:

Use local signing when your backend handles all transactions securely.

<CodeGroup>
  ```typescript TypeScript theme={null}
  import { createWalletClient, http, Hex } from "viem";
  import { privateKeyToAccount } from "viem/accounts";
  import { polygon } from "viem/chains";
  import { RelayClient } from "@polymarket/builder-relayer-client";
  import { BuilderConfig } from "@polymarket/builder-signing-sdk";

  const account = privateKeyToAccount(process.env.PRIVATE_KEY as Hex);
  const wallet = createWalletClient({
    account,
    chain: polygon,
    transport: http(process.env.RPC_URL),
  });

  const builderConfig = new BuilderConfig({
    localBuilderCreds: {
      key: process.env.POLY_BUILDER_API_KEY!,
      secret: process.env.POLY_BUILDER_SECRET!,
      passphrase: process.env.POLY_BUILDER_PASSPHRASE!,
    },
  });

  const client = new RelayClient(
    "https://relayer-v2.polymarket.com/",
    137,
    wallet,
    builderConfig,
  );
  ```

  ```python Python theme={null}
  import os
  from py_builder_relayer_client.client import RelayClient
  from py_builder_signing_sdk import BuilderConfig, BuilderApiKeyCreds

  builder_config = BuilderConfig(
      local_builder_creds=BuilderApiKeyCreds(
          key=os.getenv("POLY_BUILDER_API_KEY"),
          secret=os.getenv("POLY_BUILDER_SECRET"),
          passphrase=os.getenv("POLY_BUILDER_PASSPHRASE"),
      )
  )

  client = RelayClient(
      "https://relayer-v2.polymarket.com",
      137,
      os.getenv("PRIVATE_KEY"),
      builder_config
  )
  ```
</CodeGroup>

Use remote signing to keep credentials on a secure server you control.

**Your signing server** receives request details and returns authentication headers:

<CodeGroup>
  ```typescript Server (TypeScript) theme={null}
  import {
    buildHmacSignature,
    BuilderApiKeyCreds,
  } from "@polymarket/builder-signing-sdk";

  const BUILDER_CREDENTIALS: BuilderApiKeyCreds = {
    key: process.env.POLY_BUILDER_API_KEY!,
    secret: process.env.POLY_BUILDER_SECRET!,
    passphrase: process.env.POLY_BUILDER_PASSPHRASE!,
  };

  // POST /sign endpoint
  export async function handleSignRequest(request) {
    const { method, path, body } = await request.json();
    const timestamp = Date.now().toString();

    const signature = buildHmacSignature(
      BUILDER_CREDENTIALS.secret,
      parseInt(timestamp),
      method,
      path,
      body,
    );

    return {
      POLY_BUILDER_SIGNATURE: signature,
      POLY_BUILDER_TIMESTAMP: timestamp,
      POLY_BUILDER_API_KEY: BUILDER_CREDENTIALS.key,
      POLY_BUILDER_PASSPHRASE: BUILDER_CREDENTIALS.passphrase,
    };
  }
  ```

  ```python Server (Python) theme={null}
  import os
  import time
  from py_builder_signing_sdk.signing.hmac import build_hmac_signature
  from py_builder_signing_sdk import BuilderApiKeyCreds

  BUILDER_CREDENTIALS = BuilderApiKeyCreds(
      key=os.environ["POLY_BUILDER_API_KEY"],
      secret=os.environ["POLY_BUILDER_SECRET"],
      passphrase=os.environ["POLY_BUILDER_PASSPHRASE"],
  )

  # POST /sign endpoint
  def handle_sign_request(method: str, path: str, body: str):
      timestamp = str(int(time.time()))

      signature = build_hmac_signature(
          BUILDER_CREDENTIALS.secret,
          timestamp,
          method,
          path,
          body
      )

      return {
          "POLY_BUILDER_SIGNATURE": signature,
          "POLY_BUILDER_TIMESTAMP": timestamp,
          "POLY_BUILDER_API_KEY": BUILDER_CREDENTIALS.key,
          "POLY_BUILDER_PASSPHRASE": BUILDER_CREDENTIALS.passphrase,
      }
  ```
</CodeGroup>

**Your client** points to your signing server:

<CodeGroup>
  ```typescript Client (TypeScript) theme={null}
  import { RelayClient } from "@polymarket/builder-relayer-client";
  import { BuilderConfig } from "@polymarket/builder-signing-sdk";

  const builderConfig = new BuilderConfig({
    remoteBuilderConfig: {
      url: "https://your-server.com/sign",
    },
  });

  const client = new RelayClient(
    "https://relayer-v2.polymarket.com/",
    137,
    wallet,
    builderConfig,
  );
  ```

  ```python Client (Python) theme={null}
  from py_builder_relayer_client.client import RelayClient
  from py_builder_signing_sdk import BuilderConfig, RemoteBuilderConfig

  builder_config = BuilderConfig(
      remote_builder_config=RemoteBuilderConfig(
          url="https://your-server.com/sign"
      )
  )

  client = RelayClient(
      "https://relayer-v2.polymarket.com",
      137,
      private_key,
      builder_config
  )
  ```
</CodeGroup>

Never expose Builder API credentials in client-side code. Use environment variables or a secrets manager.

Wallet Types

Choose a wallet type when initializing the client:

Type	Deployment	Best For
Safe	Call `deploy()` before first transaction	Most builder integrations
Proxy	Auto-deploys on first transaction	Magic Link users

```typescript Safe Wallet (TypeScript) theme={null} import { RelayClient, RelayerTxType } from "@polymarket/builder-relayer-client";

const client = new RelayClient( "https://relayer-v2.polymarket.com/", 137, wallet, builderConfig, RelayerTxType.SAFE, );

// Deploy before first transaction const response = await client.deploy(); const result = await response.wait(); console.log("Safe Address:", result?.proxyAddress);


```python Safe Wallet (Python) theme={null}
from py_builder_relayer_client.client import RelayClient

# client initialized with builder_config (see Client Setup above)

# Deploy before first transaction
response = client.deploy()
result = response.wait()
print("Safe Address:", result.get("proxyAddress"))

import { RelayClient, RelayerTxType } from "@polymarket/builder-relayer-client";

const client = new RelayClient(
  "https://relayer-v2.polymarket.com/",
  137,
  wallet,
  builderConfig,
  RelayerTxType.PROXY,
);

// No deploy needed - auto-deploys on first transaction

from py_builder_relayer_client.client import RelayClient

# client initialized with builder_config (see Client Setup above)
# No deploy needed - auto-deploys on first transaction

Executing Transactions

Use the execute method to send transactions through the relayer:

interface Transaction {
  to: string; // Target contract address
  data: string; // Encoded function call
  value: string; // POL to send (usually "0")
}

const response = await client.execute(transactions, "Description");
const result = await response.wait();

Token Approval

Approve contracts to spend tokens:

```typescript TypeScript theme={null} import { encodeFunctionData, maxUint256 } from "viem";

const USDC = "0x2791Bca1f2de4661ED88A30C99A7a9449Aa84174"; const CTF = "0x4D97DCd97eC945f40cF65F87097ACe5EA0476045";

const approveTx = { to: USDC, data: encodeFunctionData({ abi: [ { name: "approve", type: "function", inputs: [ { name: "spender", type: "address" }, { name: "amount", type: "uint256" }, ], outputs: [{ type: "bool" }], }, ], functionName: "approve", args: [CTF, maxUint256], }), value: "0", };

const response = await client.execute([approveTx], "Approve USDC.e for CTF"); await response.wait();


```python Python theme={null}
from web3 import Web3

USDC = "0x2791Bca1f2de4661ED88A30C99A7a9449Aa84174"
CTF = "0x4D97DCd97eC945f40cF65F87097ACe5EA0476045"
MAX_UINT256 = 2**256 - 1

approve_tx = {
    "to": USDC,
    "data": Web3().eth.contract(
        address=USDC,
        abi=[{
            "name": "approve",
            "type": "function",
            "inputs": [
                {"name": "spender", "type": "address"},
                {"name": "amount", "type": "uint256"}
            ],
            "outputs": [{"type": "bool"}]
        }]
    ).encode_abi(abi_element_identifier="approve", args=[CTF, MAX_UINT256]),
    "value": "0"
}

response = client.execute([approve_tx], "Approve USDC.e for CTF")
response.wait()

Redeem Positions

Exchange winning tokens for USDC.e after market resolution:

```typescript TypeScript theme={null} import { encodeFunctionData } from "viem";

const redeemTx = { to: CTF_ADDRESS, data: encodeFunctionData({ abi: [ { name: "redeemPositions", type: "function", inputs: [ { name: "collateralToken", type: "address" }, { name: "parentCollectionId", type: "bytes32" }, { name: "conditionId", type: "bytes32" }, { name: "indexSets", type: "uint256[]" }, ], outputs: [], }, ], functionName: "redeemPositions", args: [collateralToken, parentCollectionId, conditionId, indexSets], }), value: "0", };

const response = await client.execute([redeemTx], "Redeem positions"); await response.wait();


```python Python theme={null}
CTF = "0x4D97DCd97eC945f40cF65F87097ACe5EA0476045"

redeem_tx = {
    "to": CTF,
    "data": Web3().eth.contract(
        address=CTF,
        abi=[{
            "name": "redeemPositions",
            "type": "function",
            "inputs": [
                {"name": "collateralToken", "type": "address"},
                {"name": "parentCollectionId", "type": "bytes32"},
                {"name": "conditionId", "type": "bytes32"},
                {"name": "indexSets", "type": "uint256[]"}
            ],
            "outputs": []
        }]
    ).encode_abi(
        abi_element_identifier="redeemPositions",
        args=[collateral_token, parent_collection_id, condition_id, index_sets]
    ),
    "value": "0"
}

response = client.execute([redeem_tx], "Redeem positions")
response.wait()

Batch Transactions

Execute multiple operations atomically in a single call:

```typescript TypeScript theme={null} const approveTx = { to: USDC, data: encodeFunctionData({ abi: erc20Abi, functionName: "approve", args: [CTF, maxUint256], }), value: "0", };

const transferTx = { to: USDC, data: encodeFunctionData({ abi: erc20Abi, functionName: "transfer", args: [recipientAddress, parseUnits("50", 6)], }), value: "0", };

// Both execute atomically const response = await client.execute( [approveTx, transferTx], "Approve and transfer", ); await response.wait();


```python Python theme={null}
approve_tx = {
    "to": USDC,
    "data": contract.encode_abi(
        abi_element_identifier="approve",
        args=[CTF, MAX_UINT256]
    ),
    "value": "0"
}

transfer_tx = {
    "to": USDC,
    "data": contract.encode_abi(
        abi_element_identifier="transfer",
        args=[recipient_address, 50 * 10**6]
    ),
    "value": "0"
}

# Both execute atomically
response = client.execute([approve_tx, transfer_tx], "Approve and transfer")
response.wait()

Batching reduces latency and ensures all transactions succeed or fail together.

Transaction States

Track transaction progress through these states:

State	Terminal	Description
`STATE_NEW`	No	Transaction received by relayer
`STATE_EXECUTED`	No	Submitted onchain
`STATE_MINED`	No	Included in a block
`STATE_CONFIRMED`	Yes	Finalized successfully
`STATE_FAILED`	Yes	Failed permanently
`STATE_INVALID`	Yes	Rejected as invalid

Contract Addresses

See Contract Addresses for all Polymarket smart contract addresses on Polygon.

Resources

Next Steps

Learn about capital-efficient trading for multi-outcome events. Understand token operations like split, merge, and redeem.

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