What the Discord and LINE APIs let an OmO agent do: practical recipes with official docs links (tested)

[Tinycute00]

Written by my OmO agent from its own measurements; I read it before posting. This is the third version of this post: it now lists practical recipes (goal, which features to combine, what you get) with the official docs for each.

I run an OmO session as an always-on assistant in a private Discord server and tested, live on 2026-09-30, what the Discord and LINE APIs allow. Status tags: phone = ran on a real phone; live = ran against the real API; unit = unit tests only; not tested. A 168 KB English package with code, tests and notes exists (see the end).

How it is wired: a small listener holds the Discord gateway and prints one line per event (OMOCAT_TAP, _SELECT, _REACT, _CMD, _SECRET, ...). OmO reads those lines with the monitor tool, so an idle session wakes on a tap or a message. A send-side CLI posts, edits, uploads and reacts.

Discord: what you want, what to combine, what you get

Goal	Combine	What you get	Status	Official docs
Answer a question with one tap	Bot pre-adds ✅ ❌ ⏰; listen for reaction add/remove (intents 1<<10, 1<<13); accept only the owner's id	Approve, refuse or snooze from the phone; removing the reaction cancels	phone	Create Reaction, Message Reaction Add, Gateway intents
Translate any message	A flag emoji is two regional-indicator characters, so map it to a country and language; read the message; reply	React 🇯🇵 and get a Japanese reply	phone	Message Reaction Add, Create Message
Ask about one message, privately	Message context-menu command (type 3) plus an ephemeral follow-up (flag 64) inside the 15-minute interaction token	Long-press, Apps, the bot; only you see the answer	phone (one guild)	message commands, followup messages
Pick among 6 to 25 options	String select (up to 25 options, min/max values); answer with callback type 7 to replace it with the choice	A dropdown that becomes "picked: A, B"	phone	String Select, interaction callback types
Enter a secret without the AI seeing it	Modal (callback type 9) with a text input; blank the value in the gateway event before anything else reads it; write a 0600 file; ephemeral confirmation	The agent only learns "saved". Same-OS-user programs can read the file, so say so in the UI	phone	Text Input, interaction callback types
Quiet progress you can scan	Silent flag 4096 on a post, edit the same message as work moves, rename the thread with 🔄 ⏸ ✅ or use forum tags	One line per job, no phone buzz on every step	live	message flags, Edit Message, Modify Channel, Forum Tag object
A status card that stays one message	Components V2 (flag 1<<15): container, text, section with a button; edit in place	A dashboard with a Refresh button	live	Components overview, Container, Section
Voice notes in and out	Download the voice-message attachment and run speech-to-text; reply with flag 8192 plus an Ogg Opus file and waveform	Talk to the agent; about 4 s to transcribe a 5 s note	live (no TTS built)	message flags
A vote or a reminder	Native poll (create, end early) or a scheduled event	Tally and timer, or a notification at start time	live (phone notification not checked)	Poll resource, Guild Scheduled Event

LINE: what you want, what to combine, what you get

Goal	Combine	What you get	Status	Official docs
Answer without paying	Reply with the event's reply token (about 1 minute, single use, up to 5 message objects per reply)	Free replies; worked at 0.2, 30 and 55 s (65 and 90 s not measured)	live	Send reply message, Messaging API pricing
Deliver a slow result for free	A rich-menu area or Flex button sends a postback with a fresh reply token	"Tap to get the result" costs nothing	live (quick-reply chip tap not tested)	Sending messages, Messaging API reference
Read what the user sends	Webhook message event, then download voice, photo or file right away; run the same speech-to-text as Discord	A LINE voice note answered as text in about 4 s	live	Receiving messages
Run the webhook safely	Verify the signature on the raw body, answer 200 within 2 s, dedupe on webhookEventId, turn redelivery on	Forged or repeated events do nothing	live	Verify webhook signature, Webhook error statistics
Show the bot is working	Loading animation (one-on-one chats, multiples of 5 seconds)	The typing-indicator equivalent	live	Loading indicator
Keep push cost down	Replies are not counted; pushes are counted per recipient (200 a month on the Taiwan free plan); a retry key stops double pushes	Predictable cost	live	Messaging API pricing, Retrying API requests
Keep messages while the home machine is off	Blind relay on a Cloudflare Worker with a SQLite Durable Object; the home machine dials out, verifies the signature (the relay never holds the secret) and dedupes	No lost events while asleep	not tested (design only)	Workers pricing, Durable Objects pricing

Limits that shape designs

Item	Limit	How we know	Source
Discord message text	2000 characters	official and measured	Create Message
Components V2 card	40 components, 4000 displayable characters	measured	Components overview
Interaction acknowledgement / token	3 seconds / 15 minutes	official; our acks took 339 to 433 ms	interaction callback types
Reactions per message	20 distinct emoji	measured (the 21st got 403)	Create Reaction
Discord upload	20 MiB per file	measured	Create Message
LINE text / objects per call	5000 characters / 5 objects	measured (both refused with 400)	Sending messages
LINE webhook	HTTPS, 200 within 2 s	official	Receiving messages

Which gateway intent for which event (Discord)

You want	Event	Intent
Messages, with their text	MESSAGE_CREATE	GUILD_MESSAGES plus MESSAGE_CONTENT (privileged)
Reactions in servers / DMs	MESSAGE_REACTION_ADD and _REMOVE	1<<10 / 1<<13, neither privileged (without them no reaction ever arrived)
Taps, selects, modals, commands	INTERACTION_CREATE	none needed (tested)
Poll votes	poll vote events	1<<24 and 1<<25 (not tested)
Official table: Gateway intents.

Surprises worth knowing

• Ephemeral flag 64 on an ordinary post is dropped and the message goes public; it only works as an interaction response.
• A LINE webhook URL cannot be cleared through the API (empty, .invalid and localhost all return 400); the "Use webhook" switch is console-only.
• agent-messenger 2.38.0 overwrites the numeric interaction type with a string, so classify from data.

Evidence and gaps

A real phone session passed 8 of 8 items. 193 unit tests run against a fake Discord server, with 30 mutation checks. Not tested: super reactions sent by a human, global command registration, phone rendering beyond read-back, LINE groups, locations, stickers and webhook redelivery.

Question for the maintainers

Is there interest in a documented messenger recipe or skill for Discord/LINE? I can turn the parts that generalize into a PR if you tell me where it belongs. I can also attach the package or publish it as a gist; tell me which you prefer.