> ## Documentation Index
> Fetch the complete documentation index at: https://docs.tai42.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Link a person across channels

> Pair a person's addresses on different channels into one conversation with a single-use code.

One person often reaches an agent from more than one place — a Telegram chat, a
WhatsApp number, a web session. **Person linking** pairs those addresses so they
share one conversation: after linking, every paired channel keys the same
[`bridge:@person:{person_id}` thread](/concepts/client-conversations#conversation-lifetime),
and the agent remembers the person across all of them rather than treating each
address as a stranger.

Linking is proven, never guessed: the person shows, from a second channel, a
single-use code minted on the first. Nothing is inferred from names or numbers.

## Turn on multichannel for the target

Linking is opt-in per target. Enable it on the agent or tool a route points at:

```bash theme={null}
tai conversations config-set agent assistant --multichannel
```

With multichannel **off**, the pairing commands below are ordinary text passed
straight through to the target, and the `get_pairing_code` tool refuses — the reach
is bounded so a target never links people unless its operator asked for it.

You can also set a first-contact greeting that hands a newcomer a code to pair with,
by referencing the `{pairing_code}` placeholder — it is filled with a fresh code on
first contact:

```bash theme={null}
tai conversations config-set agent assistant --multichannel \
  --greeting-template 'Hi! To link another channel, send this code there: {pairing_code}'
```

## Mint a code

A code is a single-use token of the shape `LINK-XXXXXXXX`. There are three ways to
mint one for a live conversation:

* **The `/link` command.** The person sends exactly `/link` to the conversation;
  the turn engine mints a fresh code and replies with it. (`/link` matches only as
  the whole message — `/link` with anything after it is ordinary text.)
* **The first-contact greeting**, if it carries `{pairing_code}` as above.
* **The `get_pairing_code` tool**, for a programmatic mint. It takes the `channel`,
  the route's `our_identity`, and the `sender` address to link, and returns
  `{code, expires_at}` and nothing else — the raw code once, never stored
  recoverably. Composing the invite around it (a typed code, or a
  [channel-web](/plugins/tai42/channel-web) `?tai_pair=` URL) is yours to do.

Minting again for the same conversation **rotates out** the previous code — the
newest code wins, and the old one stops redeeming.

## Redeem it from the other channel

From a **different** channel, the person sends the code to the same agent. It
redeems when the `LINK-XXXXXXXX` token appears anywhere in the message — typed on
its own, pasted inside a sentence, or carried by a channel-web `?tai_pair=` link. If a
message carries more than one code, the first wins. Redeeming merges the two
addresses into one person, and from then on both channels share the one thread.

## Unlink

To detach the sending address from its person, the person sends exactly `/unlink`
from that channel. It affects only the address it was sent from.

## See also

* [Client conversations](/concepts/client-conversations) — the person thread and the bridge model.
* [Conversation bridge reference](/reference/conversation-bridge) — the `person_id` / `person_addresses` payload keys and every setting.
* [WhatsApp to an agent](/guides/whatsapp-to-agent) — bridging a channel to an agent in the first place.