• Messaging Platforms
• Other
• LINE

LINE Setup

Run Hermes Agent as aLINEbot via the official LINE Messaging API. The adapter lives as a bundled platform plugin underplugins/platforms/line/— no core edits, just enable it like any other platform.

plugins/platforms/line/

LINE is the dominant messaging app in Japan, Taiwan, and Thailand. If your users live there, this is how they reach you.

Runhermes gateway setupand pickLINEfor a guided walk-through.

Runhermes gateway setupand pickLINEfor a guided walk-through.

hermes gateway setup

How the bot responds​

U C R

Inbound text, images, audio, video, files, stickers, and locations are all handled. Outbound text uses thefree reply token first(single-use, ~60s window) and falls back to the metered Push API when the token has expired.

Step 1: Create a LINE Messaging API channel​

1. Go to theLINE Developers Console.
2. Create a Provider, then under it aMessaging APIchannel.
3. From the channel’sBasic settingstab, copy theChannel secret.
4. From theMessaging APItab, scroll toChannel access token (long-lived)and clickIssue. Copy the token.
5. In theMessaging APItab, also disableAuto-reply messagesandGreeting messagesso they don’t fight your bot’s replies.

Step 2: Expose the webhook port​

LINE delivers webhooks over public HTTPS. The default port is8646— override withLINE_PORTif needed.

8646 LINE_PORT

# Cloudflare Tunnel (recommended for production — fixed hostname)cloudflared tunnel --url http://localhost:8646# ngrok (good for dev)ngrok http 8646# devtunneldevtunnel create hermes-line --allow-anonymousdevtunnel port create hermes-line -p 8646 --protocol httpsdevtunnel host hermes-line

Copy thehttps://…URL — you’ll set it as the webhook URL below.Leave the tunnel runningwhile testing. For production, set up a fixed Cloudflare named tunnel so the webhook URL doesn’t change on restart.

https://...

Step 3: Configure Hermes​

Add to~/.hermes/.env:

~/.hermes/.env

LINE_CHANNEL_ACCESS_TOKEN=YOUR_LONG_LIVED_TOKENLINE_CHANNEL_SECRET=YOUR_CHANNEL_SECRET# Allowlist — at least one of these (or LINE_ALLOW_ALL_USERS=true for dev)LINE_ALLOWED_USERS=U1234567890abcdef...           # comma-separated U-prefixed IDsLINE_ALLOWED_GROUPS=C1234567890abcdef...          # optional group IDsLINE_ALLOWED_ROOMS=R1234567890abcdef...           # optional room IDs# Required for image / audio / video sends — the public HTTPS base URL# the tunnel resolves to.  Without it, send_image/voice/video will refuse.LINE_PUBLIC_URL=https://my-tunnel.example.com

Then in~/.hermes/config.yaml:

~/.hermes/config.yaml

gateway:  platforms:    line:      enabled: true

That’s enough — the bundled-plugin scan ingateway/config.pyautomatically picks upplugins/platforms/line/. NoPlatform.LINEenum edit, no_create_adapterregistration.

gateway/config.py plugins/platforms/line/ Platform.LINE _create_adapter

Step 4: Set the webhook URL​

Back in the LINE console:

1. Open your channel →Messaging APItab.
2. UnderWebhook settings→Webhook URL, pastehttps:///line/webhook(note the/line/webhookpath — the adapter listens there).
3. ClickVerify. LINE pings the URL; you should see a 200.
4. ToggleUse webhooktoOn.

https://<your-tunnel>/line/webhook /line/webhook

Step 5: Run the gateway​

hermes gateway

The agent log shows:

LINE: webhook listening on 0.0.0.0:8646/line/webhook (public: https://my-tunnel.example.com)

Add the bot as a friend from the LINE app (scan the QR in the channel’sMessaging APItab) and send it a message.

Slow LLM responses​

LINE’s reply token is single-use and expires roughly 60 seconds after the inbound event. Slow LLMs can’t reply in time, which would normally force a paid Push API call.

When the LLM is still running pastLINE_SLOW_RESPONSE_THRESHOLDseconds (default45), the adapter consumes the original reply token to send aTemplate Buttonsbubble:

LINE_SLOW_RESPONSE_THRESHOLD 45

🤔 Still thinking. Tap below to fetch the answer when it’s ready.[ Get answer ]

🤔 Still thinking. Tap below to fetch the answer when it’s ready.

[ Get answer ]

The user tapsGet answerwhen convenient — that postback delivers afreshreply token, which the adapter uses to send the cached answer (still free).

State machine:PENDING → READY → DELIVERED, plusERRORfor cancelled runs (the orphan PENDING resolves to “Run was interrupted before completion.” after/stopso the persistent button doesn’t loop).

PENDING → READY → DELIVERED ERROR /stop

To disable the postback button and always Push-fallback instead:

LINE_SLOW_RESPONSE_THRESHOLD=0

For the postback flow to fire reliably, suppress chatter that would consume the reply token before the threshold:

# ~/.hermes/config.yamldisplay:  interim_assistant_messages: false  platforms:    line:      tool_progress: off

Cron / notification delivery​

LINE_HOME_CHANNEL=Uxxxxxxxxxxxxxxxxxxxx     # default delivery target

Cron jobs withdeliver: lineroute toLINE_HOME_CHANNEL. The adapter ships a standalone Push-only sender so cron jobs work even when cron runs in a separate process from the gateway.

deliver: line LINE_HOME_CHANNEL

Environment variable reference​

LINE_CHANNEL_ACCESS_TOKEN LINE_CHANNEL_SECRET LINE_HOST 0.0.0.0 LINE_PORT 8646 LINE_PUBLIC_URL LINE_ALLOWED_USERS LINE_ALLOWED_GROUPS LINE_ALLOWED_ROOMS LINE_ALLOW_ALL_USERS false LINE_HOME_CHANNEL LINE_SLOW_RESPONSE_THRESHOLD 45 0 LINE_PENDING_TEXT LINE_BUTTON_LABEL LINE_DELIVERED_TEXT LINE_INTERRUPTED_TEXT /stop

Troubleshooting​

“invalid signature” on webhook verify.TheChannel secretwas copied wrong, or your tunnel rewrote the request body. Verify withcurl -i https:///line/webhook/healthfirst — that should return{"status":"ok","platform":"line"}.

Channel secret curl -i https://<tunnel>/line/webhook/health {"status":"ok","platform":"line"}

Bot receives nothing in groups.CheckLINE_ALLOWED_GROUPSincludes theC…group ID. To find a group ID, send a test message and grep~/.hermes/logs/gateway.logforLINE: rejecting unauthorized source— the rejected source dict has the IDs.

LINE_ALLOWED_GROUPS C... ~/.hermes/logs/gateway.log LINE: rejecting unauthorized source

send_imagefails with “LINE_PUBLIC_URL must be set”.LINE’s Messaging API does not accept binary uploads — images, audio, and video must be reachable HTTPS URLs. SetLINE_PUBLIC_URLto the tunnel’s public hostname and the adapter will serve files from/line/media//automatically.

send_image LINE_PUBLIC_URL /line/media/<token>/<filename>

Postback button never appears.Either the LLM responded faster thanLINE_SLOW_RESPONSE_THRESHOLD, or another bubble (tool-progress, streaming) consumed the reply token first. See the suppression block under “Slow LLM responses”.

LINE_SLOW_RESPONSE_THRESHOLD

“already in use by another profile”.The same channel access token is bound to another running Hermes profile. Stop the other gateway or use a separate channel.

Limitations​

• Bubble and length caps.Each LINE text bubble is capped at 5000 characters. Longer responses are smart-chunked at ~4500 characters across up to 5 bubbles per Reply/Push call, splitting on natural boundaries where possible.
• No native message editing.LINE has no edit-message API — streaming responses always send fresh bubbles, never edit prior ones.
• No Markdown rendering.Bold (*), italics (), code fences, and headings render as literal characters. The adapter strips them before sending; URLs are preserved (labelbecomeslabel (url)).
• Loading indicator is DM-only.LINE rejects the chat/loading API for groups and rooms, so the typing indicator only shows in 1:1 chats.

** * [label](url) label (url)