Sender identifiers

In a few words

from accepts different values by channel: a phone number, address, @username, or resource name.
When an ID or alias is supplied, the backend resolves it inside the API key workspace and enforces the key’s resource restrictions.
Prefer resource IDs in long-lived integrations; aliases can make configuration and payloads easier to read.

What each channel accepts

Channel / resource	Accepted values in `from`
WhatsApp — messages	Instance ID, line’s E.164 phone number, or instance name. A sending pool ID or name is also accepted.
WhatsApp — presence and calls	Instance ID, E.164 phone number, or instance name. Pools do not apply to presence or calls.
Instagram	Instance ID, name, or connected account username, with or without `@` (for example, `shop` or `@shop`).
Telegram	Instance ID, name, or bot username, with or without `@` (for example, `alerts` or `@alerts_bot`).
RCS	Instance ID or branded agent name.
Push	App ID or name. `pushAppId` remains available on routes that expose this legacy field.
SMS and voice	Source number ID or an active E.164 phone number available to the workspace.
Email	Sender email address on a verified domain, optionally with a display name, such as `Support <help@example.com>`. This is not an instance ID.

Each endpoint documents its own field. For example, WhatsApp presence accepts from and keeps instanceId as a legacy alias; the email send API expects an email address in from.

Example: select Instagram by @username

Use the username of the connected Instagram account as the sender selector:

{
  "from": "@myshop",
  "to": ["17841400000000000"],
  "type": "text",
  "payload": { "text": "Hello!" }
}

to is still the recipient identifier required by the official API (IGSID). @ only selects the sender account.

If an alias does not identify one account

If duplicate names match more than one resource, the API returns 409 AMBIGUOUS_SENDER and asks for the resource ID. An alias from another workspace can never select resources there: resolution is limited to the API key workspace. instanceIds, pushAppIds, and equivalent API key restrictions still apply after resolution. The legacy instanceId field remains accepted by routes that declare it. On routes with from, that is the preferred field. Check the channel reference to confirm which aliases a specific operation accepts.

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Sender identifiers

In a few words

What each channel accepts

Example: select Instagram by @username

If an alias does not identify one account

​In a few words

​What each channel accepts

​Example: select Instagram by @username

​If an alias does not identify one account

In a few words

What each channel accepts

Example: select Instagram by @username

If an alias does not identify one account