Review risky tool calls before they run.

Choose the calls

Select the tools that need a human decision. Other tools on that route pass through without approval.

Bind each approval

Review the tool and its arguments. An approval cannot authorize a second execution.

Inspect the decision

Keep a signed decision receipt. Check its signature and replay separately; it does not prove an effect occurred.

Start with the harmless demo. Run it locally to inspect your own approval and replay outcome.

Approve the exact tool call.

seal demo

Recorded CLI transcript, not a captured client session. Run the demo after installing Seal.

Guarantees & limits

Seal is a local approval gate for selected Claude Code MCP tool calls. Review the exact request, allow at most one execution per approval, and inspect a signed decision receipt.

Seal is a gate, not a sandbox. Calls and effects outside the configured Seal route remain outside its control.

The decision leaves a signed receipt. Open it in the browser checker or use the assurance CLI to see what the recorded evidence establishes.

The companion tools let you check recorded evidence separately from the running Seal deployment. The browser checker and CLI share kernel and receipt-format dependencies, so their agreement can also reflect a shared defect. A passing receipt check establishes only the properties it reports; it does not by itself establish operator identity or prove that a tool effect occurred.

Lean proofs cover specified decision-model properties. Seal currently documents that correspondence between its proved authorization model and shipped authorization path is neither tested nor proved. Read the current assurance scope for the evidence and remaining assumptions.

Take it to your own tools

After the demo, choose what to protect, check a receipt, or explore the assurance tools.

• Install the gate Seal Install Seal, run the demo, then choose the tool calls that need approval.
• Check a receipt ↗ seal-check Open the browser checker to inspect the checks supported for your decision receipt.
• Review the evidence seal-assurance-kit Run receipt, policy-coverage and conformance checks from the command line.

Decision receipt Recorded example

demo.mutate

Recorded decision: BLOCK

Document structure

Valid

Signature & bindings

Valid

Verifier-local replay

Reproduced

Operator authority

Not established

Event occurrence

Not established

Recorded result for the bundled public specimen, not a live check — open the browser checker guide to run this yourself against the example receipt and its demo public key.

• Operate Seal
• Understand receipts
• Troubleshoot a refusal
• Architecture and verification relationships