# Mermail Mailbox Custom Labels List

> Mermail Mailbox Custom Labels List is a paid API for AI agents from console.mermail.app, paid per call via x402, price unknown, status unknown (last checked 2026-10-11).

Retrieves all custom labels defined for a specific Mermail mailbox, returning their IDs and names.

## Facts

- Endpoint: GET https://console.mermail.app/api/agent/v1/mailboxes/%7BmailboxId%7D/custom-labels?utm_source=zero.xyz
- Price: price unknown
- Payment: x402
- Status: unknown
- Last checked: 2026-10-11
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/mermail-mailbox-custom-labels-list-97548e89
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_V0Bk2LKvZwYCp2d_kNcJn

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability mermail-mailbox-custom-labels-list-97548e89
```

Example prompt: What custom labels are set up in my Mermail mailbox mb_abc123? I need the list of label names and IDs so I can tag incoming messages correctly.

## When to prefer this

Use this endpoint when an agent needs to discover or enumerate available labels before tagging, filtering, or routing messages in a Mermail mailbox. Prefer this over hardcoding label IDs, as it ensures the agent always works with current, valid label definitions.

## Known failure modes

- Invalid or nonexistent mailboxId returns a 404 not found error
- Missing or invalid authentication returns a 401 or 402 payment-required response
- Mailbox has no custom labels — returns an empty array
- Rate limiting or service unavailability returns 429 or 503

## How this service works

An inbox and wallet for your AI agent. Find and nurture sales leads, resolve customer support, and handle online purchases with controlled payments.

## Output

Returns a JSON array of custom label objects, each containing an 'id' (e.g. 'label_1') and a 'name' (e.g. 'Follow up'). The list represents all user-defined labels configured for the specified mailbox.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET",
      "HEAD",
      "DELETE"
     ],
     "type": "string"
    },
    "headers": {
     "type": "object",
     "additionalProperties": {
      "type": "string"
     }
    },
    "queryParams": {
     "type": "object",
     "additionalProperties": {
      "type": "string"
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "array",
     "items": {
      "type": "object",
      "properties": {
       "id": {
        "type": "string"
       },
       "name": {
        "type": "string"
       }
      },
      "additionalProperties": true
     }
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": [
  {
   "id": "label_1",
   "name": "Follow up"
  }
 ]
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/mermail-mailbox-custom-labels-list-97548e89/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from console.mermail.app](https://www.zero.xyz/host/console.mermail.app/llms.txt)