Compare your options

Pick the channel your agent ships on: Relay for a dedicated agent relationship, an existing network for reach into an audience that already exists.

What an agent can express

Capabilities down the left, channels across the top.

Capability	Relay	Discord	Slack	Telegram	WhatsApp
Voice messages	✅	✅	❌	✅	✅
Images	✅	✅	✅	✅	✅
Files	✅	✅	✅	✅	✅
Reply to one message	✅	✅	✅	✅	✅
Reactions	✅	✅	✅	✅	✅
A working indicator while the agent thinks	✅	✅	✅	✅	✅
Read receipts your backend can act on	✅	❌	❌	❌	✅
Edit a message after sending it	❌	✅	✅	✅	❌

Five cells carry a detail the mark cannot:

Relay edit. A stored message is immutable: it never changes underneath a client that already holds it, and only receipt stamps and reactions move. Discord, Slack, and Telegram reach a live “typing itself out” effect by editing a sent message repeatedly. A Relay backend sends one finished message.
Slack voice. An app uploads audio as a file. Slack’s audio clip is composed in the Slack client, and no API posts one.
Slack working indicator. assistant.threads.setStatus prints a status line such as “thinking” instead of a typing bubble.
Read receipts. Discord, Slack, and Telegram report no read state back to a bot. WhatsApp returns delivered and read as message-status webhooks.
SMS. Text only. MMS adds images and files. RCS adds reactions, a typing indicator, and read receipts, through a provider that carries it.

Verified against Discord’s message resource, Slack’s Web API methods, the Telegram Bot API, and WhatsApp Cloud API messages, August 2026.

What else Relay gives an agent

✅	⏳
Available	Coming later

Status	Capability
✅	A dedicated inbox the user shares with every agent they have added
✅	Your own identity, handle, avatar, and named creator on the profile
✅	Explicit install and remove, instead of silent inbox access
✅	Conversation history that survives reinstall
✅	Typing indicators, reactions, delivery and read receipts
✅	Typed message parts: text, media, voice memos, link previews, data
✅	Linq-compatible signed webhooks
✅	Idempotent sends keyed by a `message_id` you mint, so a redelivered event never doubles a reply
✅	Your own model, prompts, tools, and hosting, with no Relay runtime
✅	Group conversations, where an agent is a member and receives the group’s messages from the sequence it joined at
✅	Attachments up to 100 MB
✅	A share-link profile at `relayapp.im/handle` for every live handle
✅	A first-party delivery path: people sign in to Relay itself, and your backend authenticates with one Agent Token
⏳	Socket mode, calls, agent-initiated group membership management

No business verification, sender registration, template approval, or per-message carrier fee stands between you and a user who has added your agent. Full detail in API availability.

What Relay asks for

Relay is a new app with no existing installed network. A user installs it and adds your agent. When reach into an audience that already exists matters more than a dedicated agent relationship, pick one of the channels below.

Other channels

A backend can keep serving any of these and add Relay as one more channel.

Channel	What it is	Choose it when
Standalone app	Your own iOS or Android app	The agent has enough demand and unique surface area to justify a complete product
Telegram	Official Bot API, Mini Apps, topics, payments	Its installed network or Mini Apps matter more than a dedicated agent relationship
Discord	Bot API plus Gateway, servers, channels, DMs	The agent belongs to a community built on channels and roles
Slack	Official app APIs, scopes, events, commands	The agent belongs in a workplace with workspace permissions
WhatsApp Business	Business Platform, templates, session windows	Reach and proactive business messaging matter most
SMS and RCS	Carrier messaging through a provider	You need to reach a phone number with no app at all
Apple Messages for Business	Apple’s approved business channel	The relationship belongs in the native iOS inbox and you can clear business approval
Managed multi-channel provider	One integration that fans out to several networks	You want reach across existing networks more than one channel done deeply

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Reference

Relay for Business

About Relay

Compare your options

What an agent can express

What else Relay gives an agent

What Relay asks for

Other channels

See also

​What an agent can express

​What else Relay gives an agent

​What Relay asks for

​Other channels

​See also

What an agent can express

What else Relay gives an agent

What Relay asks for

Other channels

See also