Lets an assistant hand a secret to a person as a one-time link that cannot be read back afterwards.
What you can do
Share a secret with a person as a one-time link instead of pasting it into chat.
Create secrets that expire, with the link readable only once.
Work without an API key by starting a 24-hour sandbox on the first tool call, whose secrets also last 24 hours.
Reuse a saved sandbox key from the local config directory for later calls.
When to use it
Useful when an assistant needs to pass a credential, token or other sensitive value to a human without leaving it in conversation history, logs or tickets. Also handy for quick trials, since a sandbox starts automatically without an account.
Requirements
Runs as a local stdio process, installed from the npm package, so Node.js is needed. Optionally set X_TKN_API_KEY (or X_TKN_API_KEY_ID) for a real account; without either, a 24-hour sandbox is created and its key is written to a sandbox.json file under the user's config directory.
Before you install
The API key is a secret passed by environment variable and, in sandbox mode, stored on disk in a local config file. Secrets created in sandbox mode expire after 24 hours, so they are not suitable for anything long-lived. Links are one-time and cannot be read back, so a lost link means the secret must be reissued.
Enable the server for the chats that should use its tools.
Desktop only via STDIO. STDIO servers start a local process, so they need the SourceWeft desktop host.
Tools
4
create_secret
Create a one-time secret link
Turn a secret (a password, API key, recovery code or private note) into a link a person opens once. The secret is encrypted on this machine before anything is sent, and X-TKN never holds the key. The link stops working once opened, or at its expiry. You cannot read the secret back afterwards: this server has no read tool. Returns the link and a code for check_status and revoke_secret. Up to 64 KB on the free Developer plan, 256 KB on Team and Enterprise.
Whether a secret link is still waiting, has been opened, expired, or was revoked. Never returns the secret. Each call is one metered operation, and a sandbox has 100 in all, so call this no more often than every 30 seconds.
Parameterscoderequired
revoke_secret
Revoke a secret link
Cancel a secret link so it can no longer be opened. Permanent, and immediate. A secret that was already opened stays opened: revoking cannot take it back from the recipient.
Parameterscoderequired
claim_sandbox
Get a link that keeps this sandbox
Get a one-time link a person opens to claim the sandbox this server's key belongs to, so the account outlives its 24 hours and keeps its secrets. Give the link only to the person who should keep it. It works once, for 30 minutes or until the sandbox ends if that is sooner, and calling this again voids the earlier link. The sandbox key itself still ends on schedule: a claimed account goes on with a Developer key created for it. Not metered. On a key that is not an unclaimed sandbox it says so and claims nothing.
Takes no parameters.
Version history
2
v1.3.0LatestOct 22, 2026
v1.2.0Oct 21, 2026
Score
65%
65% of the applicable checks met
How complete this listing is, computed from the registry entry, the endpoint and public sources. Not a rating of the server and not a statement that it is safe or working today: reachability is a dated check, and no installs or reviews go into the score.
Reached in the last 30 days25 pts
Auth declared10 pts
Declare the credential headers in the registry entry, or keep the endpoint answering the probe so its auth can be classified.
Tools listedRequired15 pts
DescriptionRequired15 pts
Logo10 pts
Documentation15 pts
Declare a GitHub repository with a README, or serve resource_documentation in the OAuth protected-resource metadata.
License10 pts
Declare a license in the repository or the registry entry.
