# MCP tool reference

1 callable tools.

Use tools/call at https://mcp.schedulerzero.com/mcp with the exact tool name and arguments below. The /tools/ paths in this view are documentation identifiers, not HTTP endpoints. Request execution is disabled for this reference.

Inputs are shown for personal API keys (bound) and for OAuth/delegated agents. Output schemas describe MCP structuredContent: native objects pass through; arrays, scalars and null use a data wrapper. Text content retains the native JSON result.

[Connect a client](/mcp/connect) · [Authentication and authorization](/authentication) · [Generated auth guide](/auth.md) · [Download tool catalog](/mcp-catalog.json) · [Agent documentation](/llms.txt)

## connect_mailbox_provider

Starts a human handoff so a workspace member can enter a Cheap Inboxes or Inboxing API key. The agent receives the workspace inboxes URL, which does not expire. Initiating this handoff requires only integration:create.

When asked to connect a mailbox vendor. Hand the URL to a member. Poll saved connections with manage_mailbox_provider_import, which requires integration:read. Do not treat the URL as time-limited.

Do not collect, transmit, or guess the vendor API key. identify and connect stay on the human page. Do not request integration:read just to start this handoff.

Return the authorization or checkout handoff to the person. The agent may initiate and inspect status, but must not complete the human approval.

Scopes: integration:create

Risk: write; confirmation: human_completion; idempotency: none.

### Input schema (personal API key)

```json
{
  "type": "object",
  "properties": {
    "workspaceId": {
      "type": "string",
      "pattern": "^([0-9a-fA-F]{8}-[0-9a-fA-F]{4}-[1-8][0-9a-fA-F]{3}-[89abAB][0-9a-fA-F]{3}-[0-9a-fA-F]{12}|00000000-0000-0000-0000-000000000000|[fF]{8}-[fF]{4}-[fF]{4}-[fF]{4}-[fF]{12})$",
      "format": "uuid"
    },
    "provider": {
      "type": "string",
      "enum": [
        "cheap_inboxes",
        "inboxing"
      ]
    }
  },
  "required": [
    "workspaceId",
    "provider"
  ],
  "patternProperties": {
    "^(?!(?:workspaceId|provider)$)[\\s\\S]*$": false
  },
  "additionalProperties": true,
  "propertyNames": {
    "type": "string",
    "enum": [
      "workspaceId",
      "provider"
    ]
  }
}
```

### Input schema (OAuth / delegated agent)

```json
{
  "type": "object",
  "properties": {
    "workspaceId": {
      "type": "string",
      "pattern": "^([0-9a-fA-F]{8}-[0-9a-fA-F]{4}-[1-8][0-9a-fA-F]{3}-[89abAB][0-9a-fA-F]{3}-[0-9a-fA-F]{12}|00000000-0000-0000-0000-000000000000|[fF]{8}-[fF]{4}-[fF]{4}-[fF]{4}-[fF]{12})$",
      "format": "uuid"
    },
    "provider": {
      "type": "string",
      "enum": [
        "cheap_inboxes",
        "inboxing"
      ]
    }
  },
  "required": [
    "workspaceId",
    "provider"
  ],
  "patternProperties": {
    "^(?!(?:workspaceId|provider)$)[\\s\\S]*$": false
  },
  "additionalProperties": true,
  "propertyNames": {
    "type": "string",
    "enum": [
      "workspaceId",
      "provider"
    ]
  }
}
```

### Output schema (structuredContent)

```json
{
  "type": "object",
  "properties": {
    "provider": {
      "type": "string",
      "enum": [
        "cheap_inboxes",
        "inboxing"
      ]
    },
    "handoffUrl": {
      "$ref": "#/$defs/HttpUrl"
    },
    "status": {
      "anyOf": [
        {
          "type": "string",
          "enum": [
            "awaiting_human"
          ]
        }
      ]
    }
  },
  "required": [
    "provider",
    "handoffUrl",
    "status"
  ],
  "patternProperties": {
    "^(?!(?:provider|handoffUrl|status)$)[\\s\\S]*$": false
  },
  "additionalProperties": true,
  "propertyNames": {
    "type": "string",
    "enum": [
      "provider",
      "handoffUrl",
      "status"
    ]
  },
  "$defs": {
    "HttpUrl": {
      "type": "string",
      "minLength": 1,
      "maxLength": 2048,
      "pattern": "^https?:\\/\\/[^\\s/$.?#][^\\s]*$"
    }
  }
}
```

### Underlying API operations

- `inboxProviderImports.prepareConnect`: `POST /v1/workspaces/:workspaceId/inbox-providers/connections/handoff`