Seal vs. Slack Workflow Builder for agent approvals
Slack Workflow Builder can post a message with Approve/Reject buttons, but it has no policy engine, no fail-closed enforcement, and no tamper-evident audit trail — and nothing stops the agent from proceeding regardless of the click. Seal routes approvals to Slack too, but the verdict is enforced in the agent's execution path and every decision is recorded in a hash-chained log.
| Dimension | Seal | Slack Workflow Builder |
|---|---|---|
| Slack approval UI | Yes | Yes |
| Verdict actually enforced | Yes — blocks the call | No |
| Policy by amount / scope / agent | Yes | No |
| Fail-closed on timeout | Yes | No |
| Tamper-evident audit trail | Yes | No |
Slack Workflow Builder is fine for lightweight team notifications. Use Seal when the click has to actually gate an irreversible agent action and be provable later.
Frequently asked questions
Can Slack buttons approve an AI agent's action?+
They can capture a click, but Slack Workflow Builder does not enforce the outcome in your agent's code, has no policy engine, and keeps no tamper-evident record. Seal uses Slack for the same one-tap UX but blocks the actual call until the verdict resolves and logs it verifiably.
Why isn't a Slack Approve button enough for agent safety?+
Because nothing ties the button to the code path. The agent can run before or regardless of the click, and there's no fail-closed default or audit chain. Seal makes the action wait on the verdict and fail closed on timeout or malformed input.