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What do you want MailUp and fastbill to do together?
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Set it up in your client
Claude Code
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claude mcp add --transport http -s project apiant-ai https://mcp.apiant.aiStart Claude Code there, approve the server, and sign in in the browser page it opens.
Claude Code guide (opens in a new tab)Claude, web and desktop
Open Customize, then Connectors, then Add custom connector, and paste the address. On Team and Enterprise an owner adds it first.
Setup guide (opens in a new tab)Cursor
Add the address to your MCP configuration as a server URL. Cursor signs you in in your browser.
Setup guide (opens in a new tab)Zed
Open Settings, then AI, then MCP Servers, then Add Server, then Add Remote Server.
Setup guide (opens in a new tab)Codex and the ChatGPT desktop app
Open Settings, then MCP servers, then Add server, and choose Streamable HTTP. From the terminal, Codex takes the address with its own add command and then signs you in.
Setup guide (opens in a new tab)Any other MCP client
Paste the address where the client asks for a remote MCP server URL, and name the server apiant-ai where it lets you. APIANT's skills reach the client over the same connection.
Setup guide (opens in a new tab)Example flows
What MailUp can start in fastbill
When New Email Message in List in MailUp
then Send Invoice by Email in fastbill
When New Group in MailUp
then Add Payment for Invoice in fastbill
Starting points drawn from the triggers and actions in the catalog today. Describe the flow you need, at any depth, and your agent builds it and tests every scenario before it ships.
Everything your agent can do with MailUp and fastbill
Triggers and actions 4 triggers · 43 actions
Trigger
New Email Message in ListA new email message was created in the list. MailUp is a multi-list environment and messages are list-specific.
Trigger
New GroupNew group added to the specified list. MailUp is a multi-list environment and groups are list-specific.
Trigger
New Recipient SubscribedThere is a new subscriber in the specified list. MailUp is a multi-list environment.
Trigger
New Recipient UnsubscribedA recipient unsubscribed from the specified list. MailUp is a multi-list environment.
Action
Add listCreate a new list. POST Console/List
Action
Add Recipient to GroupAdd recipient to the specified group on the list.
Action
Add Recipient to ListAdds a new recipient to the specified list as a subscriber.
Action
Create New Email MessageCreate a new email message on the specified list.
Action
Create New GroupAdd a new group to the specified list. MailUp is a multi-list environment.
Action
Delete email messageDelete an email message. DELETE Console/List/{id_List}/Email/{id_Message}
Action
Delete groupDelete a group in a list. DELETE Console/List/{id_List}/Group/{id_Group}
Action
Delete listDelete a list. DELETE Console/List/{id_List}
Action
Get email messageRetrieve email message details. GET Console/List/{id_List}/Email/{id_Message}
Action
Get listRetrieve list details by id. GET Console/List/{id_List}
Action
List email messagesRetrieve email messages of a list. GET Console/List/{id_List}/Emails
Action
List Email Message Sendingslists the sendings (send tasks, with recipients count and status) created for an email message.
Action
List Group RecipientsLists the recipients in a MailUp group (GET Console/Group/{id_group}/Recipients), with id, email, name and personal data fields.
Action
List groupsRetrieve groups of a list. GET Console/List/{id_List}/Groups
Action
List listsRetrieve the console's lists. GET Console/List on services.mailup.com/API/v1.1/Rest/ConsoleService.svc
Action
List subscribed recipientsRetrieve subscribed recipients of a list. GET Console/List/{id_List}/Recipients/Subscribed
Action
Remove recipient from groupUnsubscribe a recipient from a group. DELETE Console/Group/{id_Group}/Unsubscribe/{id_Recipient}
Action
Remove Recipient From ListThis method unsubscribe the given recipient from the specified list.
Action
Send Message to Email AddressSends the specified message (previously created in MailUp in the specified List) to the email address specified.
Action
Send Message to GroupSend a message to a predefined group in the specified list.
Action
Send message to listSend an email message to all recipients of a list. POST Console/List/{id_List}/Email/{id_Message}/Send
Action
Unsubscribe recipient from listUnsubscribe a recipient from a list. DELETE Console/List/{id_List}/Unsubscribe/{id_Recipient}
Action
Update email messageModify an email message. PUT Console/List/{id_List}/Email/{id_Message}
Action
Update groupModify a group in a list. PUT Console/List/{id_List}/Group/{id_Group}
Action
Update listModify details of a list. PUT Console/List/{id_List}
Action
Add Payment for InvoiceAdds full payment for invoice
Action
Add Payment for RevenueAdds full payment for revenue
Action
Create CustomerCreates a new customer in FastBill
Action
Create InvoiceCreates a new invoice
Action
Create OfferCreates a new offer in FastBill
Action
Create RevenueCreates a revenue entry
Action
Delete CustomerDelete a FastBill customer by ID.
Action
Delete InvoiceDelete a FastBill invoice by ID.
Action
Delete OfferDelete a FastBill offer/estimate by ID.
Action
Finalize InvoiceConverts an invoice draft to a final invoice
Action
Get CustomerFetch a single FastBill customer by ID.
Action
Get InvoiceFetch a single FastBill invoice by ID.
Action
Get OfferFetch a single FastBill offer/estimate by ID.
Action
Search CustomerSearch for a Customer
Action
Search InvoiceFind an invoice
Action
Send Invoice by EmailSend an invoice by email
Action
Update CustomerUpdate fields on an existing FastBill customer.
Action
Update InvoiceUpdate fields on an existing (draft) FastBill invoice.
No trigger or action matches that. Ask your agent to add it: it reads the API documentation and builds what you describe.
Each app on its own
Reviews
What our customers say
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Questions
MailUp and fastbill, answered
What can start an automation from MailUp?
Any of MailUp's 4 triggers in the catalog, including New Email Message in List, New Group, New Recipient Subscribed and New Recipient Unsubscribed. Describe the moment in plain language and your agent picks the right one.
What can your agent do in fastbill when something happens in MailUp?
Any of fastbill's 18 actions, including Create Customer, Create Invoice, Create Offer and Create Revenue. Your agent maps the data both ways and tests every scenario before it ships.
Can it also run from fastbill to MailUp?
fastbill has no triggers in the catalog today, so automations start in MailUp. If you need the other direction, ask: your agent reads fastbill's API documentation and adds it.
Do I have to build a connector for MailUp or fastbill?
No. Both are in the catalog with their triggers and actions. You describe the automation; your agent builds it, tests every scenario and keeps it running.
What happens when something fails?
Your agent works that out for you. It plans the failure paths along with the happy path, then tests every scenario before it ships.
Is there a free plan?
Yes. Every plan includes the agent, including free, and building from your own AI client spends no assistant credits.