---
url: "https://predictiontoolkit.com/guides/polymarket-api-key/"
publisher: "PredictionToolkit"
dateModified: "2026-11-02"
---

[← Polymarket guides](<https://predictiontoolkit.com/guides/>) 

# Polymarket API authentication: choose the task first

By PredictionToolkit · Updated 2026-10-05

There is no universal Polymarket key for every operation. This source-based guide helps select the interface and identify private-access requirements; it does not report an authenticated integration test.

## Before you begin

-   Define a read-only dataset or a specific private CLOB action.
-   Use current official documentation; an operator-controlled wallet is relevant only when private access is necessary.
-   Plan to keep secrets out of this directory, public logs and issue reports.

## Choose the API without creating credentials

Gamma provides public market metadata without a trading key. Data API handles positions and activity; CLOB handles books and separately private order management. Record the chosen host and check whether the exact action is public before generating credentials. This selection is a documentation decision, not a successful API request.

## Identify the L1 prerequisite

For private CLOB access, the provider describes an operator-controlled EIP-712 ClobAuth wallet signature to create or derive API credentials. Read signer address, current timestamp, nonce and signature requirements. The output of this step is a list of prerequisites, not a signed message or credential. Reading the specification does not establish eligibility.

## Plan L2 request signing

The documented second layer uses API credentials for HMAC-SHA256 private-request signing. Identify the five required headers and exact body serialization in current official documentation. Order placement additionally requires a wallet signature authorizing the order: L2 request authentication does not replace it. Plan storage and revocation outside this site.

## Check your result

-   Name the public or private API surface and explain why credentials are or are not needed.
-   Distinguish L1 credential creation, L2 request headers and the separate signed order.
-   Obtain provider-owned eligibility, secure-storage and revocation instructions before creating any real credential.

## What this guide has not verified

No message was signed, credential created, rotated or revoked, authenticated request sent or order placed for this guide. Account eligibility and a rotation procedure were not established. A published endpoint does not prove uptime, latency or trading permission. Never submit private keys, secrets, passphrases or signatures to the directory.

## Continue researching

-   [Polymarket APIs and Data Providers](<https://predictiontoolkit.com/polymarket-api/>)  · context: Compare API responsibilities.
-   [Polymarket Gamma API: Event and Market Discovery API](<https://predictiontoolkit.com/tools/polymarket-gamma-api/>)  · context: Read the public discovery profile.
-   [Polymarket Data API: turn public activity into wallet analytics](<https://predictiontoolkit.com/tools/polymarket-data-api/>)  · context: Review positions and activity access.
-   [Polymarket CLOB API: read books and implement order handling](<https://predictiontoolkit.com/tools/polymarket-clob-api/>)  · context: Inspect books and private-order requirements.
-   [Polymarket API endpoints: Gamma, CLOB and Data](<https://predictiontoolkit.com/guides/polymarket-api-endpoints/>)  · context: Match hosts and identifiers.
-   [Polymarket SDKs and Developer Libraries](<https://predictiontoolkit.com/polymarket-sdks/>)  · context: Choose a client after deciding access.