---
title: "Tools: SD-JWT, JWS, RFC 9421, status list, timestamp"
url: https://knowyouragent.ch/en/tools
lang: en
updated: 2026-10-12
license: © Innopulse Consulting GmbH
---

# Tools

Five tools to read and understand evidence from AI agents. Everything runs locally in the browser; nothing is transmitted.

## All tools

- [SD-JWT decoder](https://knowyouragent.ch/en/tools/sd-jwt-decoder)Decode SD-JWT and [SD-JWT VC](https://knowyouragent.ch/en/knowledge/glossary/sd-jwt-vc) locally: header, claims, disclosures with digest matching and the [key binding](https://knowyouragent.ch/en/knowledge/glossary/key-binding) JWT, without the token leaving the browser.

- [JWS and JWT decoder](https://knowyouragent.ch/en/tools/jwt-decoder)Decode JWT and JWS locally: header, payload, times and signature length, without the token going to a server. For decisions, receipts and status lists.

- [RFC 9421 signature base](https://knowyouragent.ch/en/tools/rfc-9421-signature-base)Build the RFC 9421 signature base from a signed HTTP request and compare it with your own implementation, locally in the browser, with the IETF example.

- [Status list decoder](https://knowyouragent.ch/en/tools/status-list-decoder)Decode an IETF Token [Status List](https://knowyouragent.ch/en/knowledge/glossary/status-list) locally: bits per entry, number of entries, revoked entries and the status at a given index.

- [Timestamp inspector (RFC 3161)](https://knowyouragent.ch/en/tools/timestamp-inspector)Read an [RFC 3161 timestamp](https://knowyouragent.ch/en/knowledge/glossary/rfc-3161-timestamp) locally: time, hash algorithm, hash of the data, serial number, timestamp authority and embedded certificates.

## Decoding is not verifying

A decoder makes visible what a token contains: header, claims, disclosures, times. It says nothing about whether the signature holds, whether the issuer is trustworthy or whether a mandate was revoked. Every output of the tools is therefore explicitly marked “decoded, not verified”.

For a reliable result, there is the [verification page](https://knowyouragent.ch/en/verify). It checks the same evidence in ten steps and returns a verdict with a level.

## Why local

Many online decoders send tokens to a server. Evidence from agents can contain names, amounts or identifiers of principals. KYA's tools compute exclusively in the browser; the page's content security policy forbids network requests from the tool.

## Frequently asked questions

### Do the tools cost anything?

No. All tools are free, need no account and run entirely in the browser.

### Are my tokens transmitted?

No. The tools make no network requests; the page's content security policy does not allow it.

### How do they differ from the verification page?

The tools show what evidence contains. The verification page checks whether it holds: signatures, issuer, validity, scope, revocation and time.

---
Quelle: https://knowyouragent.ch/en/tools · KYA – Know Your Agent