This is your side. The agents' side, to give them: pki.sgit.ai/handover.md.

Agents and vault keys: what you do

Four recipes, for you, Dinis: the person whose key is the root (sha256:db7f79fdd87e030a). The agents' side of each is in handover.md, which you give them; this page is yours. In every recipe a key travels sealed to the key that should open it, and you carry an image.

1. Give an agent a vault key you hold

You have the key (an agent sealed it to you); another agent needs it. It does not need to be enrolled for this.

Ask the agent for its key. Paste into its session: Read https://pki.sgit.ai/handover.md. If you have no key, make one. Then run node pki-agent.mjs keyqr --out key.png and give me the image and your fingerprint.
Open the message that carries the vault key, at pki.sgit.ai/m/, with your vault open: choose, drop or paste its QR image.
On the file, press "Forward, sealed, to…", and choose the agent's key image (or paste its key link). The page shows the key's fingerprint: compare it, character for character, with the one the agent printed. That comparison is what makes the key the agent's.
Press "Seal it to them", then Download PNG (or Copy the image).
Give the image to the agent, with: Open this with node pki-agent.mjs open <image> --save <folder>. The sender is me, sha256:db7f79fdd87e030a.

Or start from the agent's key (either order works): bring its key image to pki.sgit.ai/m/. The page shows its fingerprint (compare it), and under it Give it a vault key you hold: pick the vault key from the messages you kept, or bring the message that carries it (its QR image), and press Seal it to ….

The vault key is sealed again in your browser's memory: it is not shown, not downloaded, not pasted. Only the agent's key opens the image, for seven days.

2. Onboard a new agent

Once per agent. After this, other agents trust it on their own, and keys move between agents without you checking fingerprints by hand.

Paste into its session: Read https://pki.sgit.ai/handover.md, section C. Run node pki-agent.mjs operator sha256:db7f79fdd87e030a and node pki-agent.mjs submission, and give me the JSON and your fingerprint.
In Your vault → Agents, paste the JSON and press Check it. Compare the fingerprint with the one the agent printed.
Choose how long: a week for a session agent; a month for one whose key lasts (the vault registry, once its key is kept as a secret). Add its behaviour policy if it has one. Sign.
Press Copy it and give the file to the site's agent (the session that runs pki.sgit.ai). It checks every signature, publishes, and the register shows the agent as operated by you.

An agent's key that lives only as long as its session dies with it. For an agent that must keep keys (the registry), give it a key that lasts: in its session, SG_SEND_PASSPHRASE=… node pki-agent.mjs keyfile, and keep the output and the passphrase as secrets of its environment (PKI_AGENT_KEY, SG_SEND_PASSPHRASE).

3. Have one agent hand a vault key to another

Both enrolled (recipe 2). You see nothing; you carry an image.

Tell the agent that has the key: Seal the vault key of <vault> to sha256:<recipient>, following https://pki.sgit.ai/handover.md, section A. Add your own fingerprint after a comma (--to <recipient>,sha256:db7f79fdd87e030a) when you want a copy you can open too.
Carry each image to the session it is for. The receiving agent checks the signature, that the sender chains to your root, and the date, and stores it (section B).

4. Receive a key yourself

Open pki.sgit.ai/m/ with your vault open and choose, drop or paste the image, several images, or a zip of them. Each message for your key opens, one under the other. A file that looks like a key stays closed until you press View. A sender not in the register is shown as such: compare its fingerprint with the one the agent gave you.

What to check, every time

The fingerprint, against the one the agent printed in its own session. Not against one in a message, a QR code or a page someone sent you.
The sender, on what you open: signed, and by whom.
The date: a sealed key expires in seven days; an older image is refused.
Never paste a vault key into a chat, yours or an agent's. If an agent prints one, treat that vault as exposed, and rekey it (sgit vault rekey).

The tool: agents/pki-agent.mjs (seal, read-qr, open, trust). Why it is built this way: agents, vault keys and the root; drawn: a vault key, handed over.