WhatSync
WhatsApp for Hermes Agent
Hermes runs on its own and learns as it goes. Add WhatSync and it can work with the people in your WhatsApp too.
How do you connect WhatsApp to Hermes Agent?
Add WhatSync under mcp_servers in ~/.hermes/config.yaml with the URL and auth: oauth, then run hermes mcp login whatsync. Hermes handles the sign-in and keeps you connected.
- Works in
- Hermes Agent
- You need
- Hermes Agent. WhatsApp on your phone, or a WhatsApp Business API number.
- WhatSync server
- Hosted for you. Nothing to run yourself.
What Hermes Agent can do with your WhatsApp
Scheduled check-ins
Have Hermes look for unanswered chats on a schedule and report back.
Memory with context
Hermes can recall what a person told you on WhatsApp when it works on their task.
Drafts on demand
Ask for a reply and approve it before it goes.
Add WhatSync to Hermes Agent
You sign in to WhatSync once. No API keys to paste. Check what you need above first.
Add the server
Add this to ~/.hermes/config.yaml.
mcp_servers: whatsync: url: "https://whatsync.app/api/mcp" auth: oauthSign in and test
Run the login from a fresh terminal so you have time to finish in the browser, then test it. On a remote machine, Hermes lets you paste the redirect link back.
hermes mcp login whatsync hermes mcp test whatsyncLink your WhatsApp
Open your WhatSync dashboard and link your personal WhatsApp from Linked devices on your phone, or connect the WhatsApp Business API. If you ask your agent something first, it replies with a sign-in link that works for 15 minutes.
Choose what it can see
On the What's saved page, enable message saving, pick the groups to include and keep any person out. Groups stay off until you tick them. The agent can read permitted messages saved since you enabled saving; linking does not import your entire WhatsApp history.
Things to ask Hermes Agent
Copy one, change the names, and try it.
Use WhatSync. Who is waiting on a WhatsApp reply from me?
Every evening, summarise my WhatsApp groups and send me the summary.
Find what Leo said about the shipment and add it to the project notes.
Good to know
You choose which chats are saved, and you can unlink WhatsApp from your phone at any time. How we handle your data.
- Hermes saves your sign-in in ~/.hermes/mcp-tokens/. Nothing secret goes in config.yaml.
- For scheduled checks, exclude the send and campaign tools in the server's tools settings. Telling Hermes to ask first is not a hard rule.
- Sends are real WhatsApp messages and run when your AI app allows the tool call. Keep send tools on manual approval and review the recipient and text. Asking the agent to wait is not an enforced approval setting.
- Use the Business API for campaigns to customers who opted in. The Business API does not permit unsolicited messages. Linked personal accounts can be restricted for violating WhatsApp's rules.
- Search covers saved message text, file names and captions. WhatSync does not index document contents, transcribe voice notes or read text inside images. A download link is available only when WhatSync saved the file.
- Group searches and replies require a linked personal WhatsApp. WhatsApp Business API tools work with customer conversations, templates and campaigns.
- An unanswered conversation means its latest saved message in the checked period is incoming. It is a follow-up signal, not proof that a question is unanswered or that you owe a reply.
Personal WhatsApp or the Business API
Hermes Agent can tell which one you have and uses the right tools for it.
Your personal WhatsApp
- Link the WhatsApp you already use, like WhatsApp Web
- Chats, groups, files, polls and reactions
- For normal one-to-one use, not bulk sending
WhatsApp Business API
- Templates and campaigns your agent can send
- Meta reviews templates and charges per message
- Only for customers who opted in
Questions
Something else? Ask us.
Does Hermes Agent support OAuth MCP servers?
auth: oauth and Hermes handles registration, sign-in and token refresh itself.Hermes runs on a server with no browser. Can I still sign in?
Do I need to install anything?
Does it work with the WhatsApp Business API?
Is WhatSync made by Nous Research?
How much does it cost?
Sources
We checked these steps against Hermes Agent's own docs on October 13, 2026. Menus change, so a screen may look a little different. WhatSync is not made or endorsed by Nous Research.
Use it in your other AI apps too
One WhatSync account works in all of them. Each guide says what you need.
Put your WhatsApp to work in Hermes Agent
Your WhatsApp keeps working on your phone as normal. Unlink it whenever you like.