# Connect Mailparser to OnceOnly

When **New Email Parsed (One Request Per Email)** fires in [Mailparser](https://apiant.ai/connections/mailparser), your agent runs **Add event** in [OnceOnly](https://apiant.ai/connections/onceonly). Describe the whole flow and it is built, tested on every scenario and kept running.

Mailparser **2** triggers OnceOnly **11** actions

What the catalog holds today. Ask for anything missing and your agent reads the API documentation and adds it.

## What do you want Mailparser and OnceOnly to do together?

Give your AI client this address.

`https://mcp.apiant.ai`

Any client that takes a remote MCP server. Nothing to install. Create your free account, then sign in once in your browser.

### Set it up in your client

### Claude Code

Run this in the directory you want to work in.

`claude mcp add --transport http -s project apiant-ai https://mcp.apiant.ai`

Start Claude Code there, approve the server, and sign in in the browser page it opens.

[Claude Code guide (opens in a new tab)](https://apiant.ai/docs/mcp/claude-code)

### 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)](https://apiant.ai/docs/mcp)

### 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)](https://apiant.ai/docs/mcp)

### Zed

Open Settings, then AI, then MCP Servers, then Add Server, then Add Remote Server.

[Setup guide (opens in a new tab)](https://apiant.ai/docs/mcp)

### 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)](https://apiant.ai/docs/mcp)

### 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)](https://apiant.ai/docs/mcp)

Example flows

## What Mailparser can start in OnceOnly

- When **New Email Parsed (One Request Per Email)** in Mailparser then **Add event** in OnceOnly
- When **New Email Parsed (One Request Per Email)** in Mailparser then **Add policy** in OnceOnly

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 Mailparser and OnceOnly

## Triggers and actions 2 triggers · 11 actions

- Trigger

**New Email Parsed (One Request Per Email)**

Triggered instantly when Mailparser finishes parsing an inbound email, with all of that email's parsed data delivered in a single request. In Mailparser, open your inbox and add a Generic Webhook under Integrations/Downstream Webhooks, paste the minted URL, and set Repeating Data Behaviour to "One request per Email". Parsed fields bind as {{ trigger.body.* }}. Use the One Request Per Row trigger instead when you are parsing tabular data and want each row handled as its own run.

- Trigger

**New Email Parsed (One Request Per Row)**

Triggered instantly for EACH parsed table row when Mailparser finishes parsing an inbound email — one run per row, for tabular data such as invoice line items or price lists. In Mailparser, open your inbox and add a Generic Webhook under Integrations/Downstream Webhooks, paste the minted URL, and set Repeating Data Behaviour to "One request per row". That row's fields bind as {{ trigger.body.* }}. Use the One Request Per Email trigger instead when you want the whole email's parsed data in a single run.

- Action

**Add event**

Adds an event to an agent run's timeline in OnceOnly, such as a step starting, a tool call, or a failure.

- Action

**Add policy**

Creates or updates the governance policy for an agent, such as rate limits, spend limits and allowed or blocked tools.

- Action

**Add tool**

Creates or updates a tool in your OnceOnly tool registry, pointing at your backend URL. Returns the saved tool without its secret.

- Action

**Check & Lock**

Checks an idempotency key and locks it if it is new, telling you whether the event is a first occurrence or a duplicate.

- Action

**Delete tool**

Permanently deletes a tool from your OnceOnly tool registry.

- Action

**Get policy**

Returns the governance policy configured for an agent.

- Action

**Get run**

Returns a run's timeline: the run id, the total number of events and the list of events recorded for it.

- Action

**Get tool**

Returns the details of a registered tool by name, including its URL, scope, enabled state and retry settings.

- Action

**List policies**

Returns every agent policy on the OnceOnly account, each with its agent id and policy settings.

- Action

**List runs**

Returns the runs recorded on your OnceOnly account, with each run's latest status and event count.

- Action

**List tools**

Returns the tools registered in your OnceOnly tool registry for a scope.

## Each app on its own

- [ **Mailparser** Send emails to Mailparser, get structured data in return.](https://apiant.ai/connections/mailparser)
- [ **OnceOnly** OnceOnly is an idempotency API that prevents duplicate automation runs by blocking repeated events in...](https://apiant.ai/connections/onceonly)

Reviews

## What our customers say

## More from Mailparser

- [ **Mailparser to HubSpot** HubSpot is your all-in-one stop for all of your marketing software needs.](https://apiant.ai/connect/mailparser-to-hubspot)
- [ **Mailparser to Salesforce** Salesforce is a leading enterprise customer relationship management (CRM) platform.](https://apiant.ai/connect/mailparser-to-salesforce)
- [ **Mailparser to Slack** Slack is a messaging platform for teams. Post messages, manage channels, users, reminders, and react to...](https://apiant.ai/connect/mailparser-to-slack)
- [ **Mailparser to Google Sheets** Google Sheets](https://apiant.ai/connect/mailparser-to-google-sheets)
- [ **Mailparser to Gmail** Gmail is Google’s email service, featuring spam protection, search functions, and seamless integration with...](https://apiant.ai/connect/mailparser-to-gmail)
- [ **Mailparser to Google Calendar** Google Calendar is a time management tool providing scheduling features, event reminders, and integration...](https://apiant.ai/connect/mailparser-to-google-calendar)

## More into OnceOnly

- [ **HubSpot to OnceOnly** HubSpot is your all-in-one stop for all of your marketing software needs.](https://apiant.ai/connect/hubspot-to-onceonly)
- [ **Salesforce to OnceOnly** Salesforce is a leading enterprise customer relationship management (CRM) platform.](https://apiant.ai/connect/salesforce-to-onceonly)
- [ **Slack to OnceOnly** Slack is a messaging platform for teams. Post messages, manage channels, users, reminders, and react to...](https://apiant.ai/connect/slack-to-onceonly)
- [ **Google Sheets to OnceOnly** Google Sheets](https://apiant.ai/connect/google-sheets-to-onceonly)
- [ **Gmail to OnceOnly** Gmail is Google’s email service, featuring spam protection, search functions, and seamless integration with...](https://apiant.ai/connect/gmail-to-onceonly)
- [ **Google Calendar to OnceOnly** Google Calendar is a time management tool providing scheduling features, event reminders, and integration...](https://apiant.ai/connect/google-calendar-to-onceonly)

Questions

## Mailparser and OnceOnly, answered

###

### What can start an automation from Mailparser?

Any of Mailparser's 2 triggers in the catalog, including New Email Parsed (One Request Per Email) and New Email Parsed (One Request Per Row). Describe the moment in plain language and your agent picks the right one.

###

### What can your agent do in OnceOnly when something happens in Mailparser?

Any of OnceOnly's 11 actions, including Add event, Add policy, Add tool and Check & Lock. Your agent maps the data both ways and tests every scenario before it ships.

###

### Can it also run from OnceOnly to Mailparser?

OnceOnly has no triggers in the catalog today, so automations start in Mailparser. If you need the other direction, ask: your agent reads OnceOnly's API documentation and adds it.

###

### Do I have to build a connector for Mailparser or OnceOnly?

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.