A session key is a permission boundary, not a second wallet

Automation often needs a signer. That does not mean it should receive the same authority as the wallet owner.

Polymarket's session-key model is useful when you think of it as a permission boundary: a separate signer for defined trading surfaces, with limits that belong in the runbook.

Start with the authority map

The session key is a separate signer authorized by the Deposit Wallet Owner. It is not a new place to store funds, and it does not replace the owner account.

Write down which owner approved the key, which signer holds it, and which service is allowed to use it. If those three lines are unclear, the automation is already hard to audit.

Scope the venue before you scope the code

The documented scopes cover CLOB, Combos, or All. Choose the narrowest scope that matches the job. A price watcher that only submits CLOB orders has no reason to inherit every available trading surface.

Scope is not a user-interface label. It is a boundary your monitoring and incident response should understand. Log the scope with each deployment and review it when the integration changes.

Put expiry on the calendar

Session keys have a documented 180-day expiration. Treat that date like a certificate rotation: record it, alert before it arrives, and make renewal an explicit change rather than a silent recovery step.

A key that expires should produce a controlled stop and a clear operator action. Quietly swapping in an unreviewed signer is the opposite of least privilege.

Reconcile the owner and the signer

Keep session-key activity beside the owner's account and order records. After a deploy, a restart, or an access change, confirm which orders were submitted, canceled, or left open.

The useful question is not whether a session key made automation easier. It is whether the owner can still explain what the signer was allowed to do, when that permission ends, and what happened after the service stopped.

Further reading: Session keys · Wallets and authentication · Manage orders.

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