Write a record for someone else

Inbox records: one user writes, another owns and reads it, and nothing on chain names either.

Sometimes the record belongs to someone other than the writer: a shop owner sends a customer a receipt, a clinic issues a result, an app hands a user a credential. With plain Arkiv the writer would have to know the recipient’s wallet and make it the owner, which links them in public.

Inbox records work like stealth addresses (ERC-5564). The recipient shares an inbox address. Anyone can write to it; each record gets a one-time owner that only the recipient controls, encrypted so only the recipient can read it.

Share your inbox address

const inbox = await alice.inboxAddress() // "arkognito-inbox1:02…"

It is stable for the user and app. Publish it wherever the writer can find it.

Send

await bob.sendTo(inbox, {
  payload: new TextEncoder().encode(JSON.stringify({ receipt: "R-1042" })),
  contentType: "application/json",
  attributes: { type: "receipt" },
  expires: ExpirationTime.fromDays(30),
})

The payload is always encrypted to the recipient. Bob’s client pays with Bob’s rate-limit token; the relayer writes the record like any other.

Receive

const alice = await createPrivateClient({ app: "my-app", wallet, inbox: true })
const mine = await alice.myEntities() // includes records sent to you; ref.kind === "inbox"
const proof = await alice.proveOwnership(mine[0].entityKey, { challenge, verifier: "desk-1" })

Scanning for inbox records costs one elliptic-curve multiplication per record in the app, so it is off unless you pass inbox: true.

What others can tell

Party	Learns	Does not learn
Anyone reading Arkiv	that a record is an inbox record (its envelope is not signed by its owner)	who it is for, who sent it, what it says
The sender	the record they wrote	anything about the recipient’s other records; they cannot read it back or prove ownership
The relayer	the same as for any record	who the recipient is