MCP reference

1. Open the dashboard

Independent hosting uses Google or Apple OAuth after the operator configures credentials, an authentication secret, the domain and database migration. Apple requires HTTPS and is shown on Apple devices. Email sign-in uses 6-digit codes when Resend and a verified sender are configured. Codes expire after 10 minutes; five failed attempts require a new code. Never share codes with an assistant. New users enter their first and last name and optional company name, then choose a trial. Connections remain in Settings, and invitations require an active Team or Max trial or subscription. Stripe Checkout is test-mode only and must be configured by the operator. A signed webhook, not a redirect, confirms completion. Completed profiles skip onboarding; Finish onboarding resumes unfinished setup at its saved checkpoint. Welcome progress is tracked without names or form contents, with demo sessions separated from live metrics. Completion is recorded after a verified trial webhook or a separate local preview completion. Local development offers an isolated demo session without email verification. An explicitly configured Cloudflare preview supports the same flow only on its exact preview host, with a separate database and no live service secrets. Standard production builds disable demos and require verified authentication. The local email sign-up password step is a UI preview only: it does not transmit or save the sample password. Live email signup creates a password and verifies email by code. Sign-in also retains the email-code option. Sign in and keep the workspace open so browser tools use your verified session.

Open the signed-in dashboard in a browser or agent host with WebMCP support. Keep that tab open. Tools register on the dashboard, not on this guide or the marketing page.

2. Check tool availability

Verified options: ChatGPT desktop’s built-in browser, when site tools are available for your account and model; or Gemini through the Model Context Tool Inspector developer extension with WebMCP enabled in Chrome. These are browser-specific setups, not a general claim that every chat app supports Postii. See the ChatGPT site-tools instructions and Inspector setup requirements.

Connect a platform opens a platform-only modal that keeps your draft in place. For the API and MCP setup tools, choose the personal/company name menu → Settings → API & MCP (open the navigation menu on mobile). Product-update cards can be dismissed locally or opened for details; they do not indicate publishing or connection status.

The connector list steps aside while a connector or setup dialog is open; closing that dialog restores the list and its state. The workspace Platforms modal opens on My platforms. The marketing homepage modal and Platforms page are browse-only catalogs without My platforms. The homepage modal has Social media and Newsletters category filters alongside search. Sidebar Platforms opens a full workspace page on My platforms by default. Each app links to its generated detail page with current capabilities and limitations. Assistant and API guided setup flows are in the separate Settings → API & MCP section.

Under the workspace menu → Settings → API & MCP, choose “Set up assistant.” Follow the numbered three-step modal: open your assistant, copy the prompt, then check API reachability. This last check does not verify your assistant’s connection. The header and Next buttons stay visible while long content scrolls. Compatibility details are expandable. The Setup guide link opens this page. Copy the prompt into your assistant. The assistant must be able to access your signed-in dashboard through a WebMCP-compatible browser and discover its registered tools. Opening this guide does not connect an assistant. If discovery is unavailable, your browser or assistant does not expose the required page tool registry.

Do not enter the dashboard URL as a remote MCP endpoint. Remote clients cannot connect directly to this browser-only interface.

3. Start with a read-only preview

{
  "tool": "post_agent_preview_post",
  "arguments": {
    "content": "A small update from our team.",
    "channels": [
      "linkedin"
    ]
  }
}

Pass the tool name and arguments through your host’s tool-calling interface. This previews text and limits without saving or publishing.

Available tools

{
  "type": "object",
  "properties": {
    "operation_id": {
      "type": "string"
    }
  },
  "additionalProperties": false
}

{
  "type": "object",
  "properties": {},
  "additionalProperties": false
}

{
  "type": "object",
  "properties": {
    "content": {
      "type": "string",
      "minLength": 1,
      "maxLength": 5000
    },
    "channels": {
      "type": "array",
      "minItems": 1,
      "uniqueItems": true,
      "items": {
        "type": "string",
        "enum": [
          "x",
          "threads",
          "facebook",
          "instagram",
          "tiktok",
          "linkedin",
          "pinterest",
          "bluesky"
        ]
      }
    }
  },
  "required": [
    "content",
    "channels"
  ],
  "additionalProperties": false
}

{
  "type": "object",
  "properties": {
    "content": {
      "type": "string",
      "minLength": 1,
      "maxLength": 5000
    },
    "channels": {
      "type": "array",
      "minItems": 1,
      "uniqueItems": true,
      "items": {
        "type": "string",
        "enum": [
          "x",
          "threads",
          "facebook",
          "instagram",
          "tiktok",
          "linkedin",
          "pinterest",
          "bluesky"
        ]
      }
    },
    "date": {
      "type": "string",
      "format": "date"
    },
    "time": {
      "type": "string",
      "pattern": "^([01]\\d|2[0-3]):[0-5]\\d$"
    },
    "auto_dm_rules": {
      "type": "array",
      "maxItems": 8,
      "items": {
        "type": "object",
        "properties": {
          "provider": {
            "type": "string",
            "enum": [
              "x",
              "threads",
              "facebook",
              "instagram",
              "tiktok",
              "linkedin",
              "pinterest",
              "bluesky"
            ]
          },
          "trigger": {
            "type": "string",
            "enum": [
              "comment_keyword",
              "comment_any",
              "like"
            ]
          },
          "keyword": {
            "type": "string",
            "minLength": 1,
            "maxLength": 64
          },
          "message": {
            "type": "string",
            "minLength": 1,
            "maxLength": 2000
          },
          "public_reply": {
            "type": "string",
            "maxLength": 500
          }
        },
        "required": [
          "provider",
          "trigger",
          "message"
        ],
        "additionalProperties": false
      }
    },
    "operation_id": {
      "type": "string",
      "minLength": 1,
      "maxLength": 128
    }
  },
  "required": [
    "content",
    "channels",
    "date",
    "time"
  ],
  "additionalProperties": false
}

{
  "type": "object",
  "properties": {
    "platforms": {
      "type": "array",
      "items": {
        "type": "string",
        "enum": [
          "x",
          "threads",
          "facebook",
          "instagram",
          "tiktok",
          "linkedin",
          "pinterest",
          "bluesky",
          "beehiiv"
        ]
      },
      "uniqueItems": true,
      "maxItems": 8
    },
    "publication_ids": {
      "type": "array",
      "items": {
        "type": "string",
        "pattern": "^pub_[a-f0-9-]+$"
      },
      "uniqueItems": true,
      "minItems": 1
    }
  },
  "required": [
    "platforms"
  ],
  "additionalProperties": false
}

{
  "type": "object",
  "properties": {
    "status": {
      "type": "string",
      "enum": [
        "all",
        "scheduled",
        "published",
        "failed"
      ]
    }
  },
  "additionalProperties": false
}

{
  "type": "object",
  "properties": {
    "content": {
      "type": "string"
    },
    "date": {
      "type": "string",
      "format": "date"
    },
    "time": {
      "type": "string",
      "pattern": "^([01]\\d|2[0-3]):[0-5]\\d$"
    }
  },
  "additionalProperties": false
}

{
  "type": "object",
  "additionalProperties": false,
  "properties": {
    "operation_id": {
      "type": "string",
      "pattern": "^[a-zA-Z0-9_-]{16,100}$"
    },
    "publication_id": {
      "type": "string"
    },
    "title": {
      "type": "string",
      "minLength": 1,
      "maxLength": 200
    },
    "content": {
      "type": "string",
      "minLength": 1,
      "maxLength": 50000
    },
    "action": {
      "type": "string",
      "enum": [
        "draft",
        "publish",
        "schedule"
      ]
    },
    "scheduled_at": {
      "type": "string",
      "format": "date-time"
    },
    "confirm": {
      "const": true
    }
  },
  "required": [
    "operation_id",
    "publication_id",
    "title",
    "content",
    "action",
    "confirm"
  ]
}

Scheduling and limits

In the browser composer, Submit now opens a local chat-style readiness review. Users can edit their shared draft, skip a destination, or resolve connection and media barriers before a separate delivery confirmation. This is rule-based feedback, not an AI conversation. WebMCP previews still return approximate text checks; they do not perform the browser review or verify account-specific limits and media compatibility.

Social scheduling saves sandbox records only. Ask the user before a write; use a stable operation_id and identical input when retrying the same schedule. Auto-DM rules remain pending, and media files are not saved by these tools. The Dashboard accepts up to 10 local images/videos in any mix, 100 MB combined, plus .txt files up to 100 KB each. Dropping media does not make it publishable through MCP or beehiiv.

The browser scheduling flow currently accepts dates from 2026-09-07 through 2026-09-13, with a future time in America/Toronto. Selecting platforms requires connected social accounts. Social app cards open their detail pages and are marked Coming soon; they do not connect accounts. The beehiiv platform page has connection controls after signup and onboarding are complete. Connect resumes unfinished onboarding or opens signup for signed-out visitors. Select beehiiv on its own with post_agent_set_platforms and publication_ids containing the specific connected publication IDs. IDs may be omitted only when exactly one publication is connected. Newsletter sends use the separate tools below, not the social scheduler.

beehiiv publishing tools

Use post_agent_get_beehiiv to discover the signed-in user’s connected publications and delivery activity. post_agent_submit_beehiiv creates a draft, publishes, or schedules through that user’s saved API key. It requires beehiiv Max/Enterprise Send API access. Ask for approval of the exact content, publication, delivery time, and website/email audience (free subscribers) before passing confirm: true. Settings → Platforms → Manage supports adding publications with an existing or new key and disconnecting individual publications. The + beside Manage opens the same Add publication flow without changing any saved connection. Keys are never exposed to these tools. A multi-publication send requires approval for every destination and one submit call per publication with a distinct operation ID. Inspect each result independently; never resend successful destinations to recover a partial failure.

Keep operation_id and input identical on retries. Never change the ID to retry an uncertain send. A successful HTTP response can contain a failed or uncertain delivery; accepted means processing, not published. Refresh with post_agent_get_beehiiv and operation_id. Drafts send nothing; scheduling requires an absolute future timestamp with a timezone.

These are Postii’s browser tools, not beehiiv’s remote MCP. beehiiv’s own MCP uses a separate OAuth connection and allows paid-plan users to create and edit drafts, but not publish or schedule. Postii does not yet provide that OAuth connection. See our beehiiv API and MCP comparison.

Troubleshooting

Signed-out visitors see Meet Postii, a chat interface with preset FAQ questions, pre-written answers, and follow-up suggestions after every answer. Visitors may also type questions to find matching help-article answers. New chat clears the conversation and restores the initial suggestions. A sign-up shortcut stays available. The conversation stays in page memory; this visitor guide does not call AI or access accounts. Signed-in users see Ask Postii!, which suggests articles locally while you type. Pressing Ask Postii sends the question and recent chat to the configured AI provider, using reviewed knowledge-base articles as references. The AI integration must be enabled by the operator; it has no account access or action tools. The disclaimer appears after you submit a question. Postii asks clarifying questions or offers troubleshooting before recommending human help. When it identifies a need to escalate, or you request a person, it can offer a support-request form addressed to contact@creatorstoolbox.com. Only your editable email and message form is submitted, not the full conversation. Requests are saved privately; forwarding requires an email provider and verified sender. An unavailable service never claims to have answered or sent an email. Article-view counts contain public IDs only, and typing alone does not send queries.

• No tools: open the dashboard, sign in, refresh tool discovery, and confirm WebMCP support in your host.
• Disconnected platform: platform selection rejects accounts that are not connected. Read-only previews can still check supported platform formats.
• Invalid input: use the schema above. Unknown fields and unsupported dates are rejected.
• Remote setup: not released. No MCP token, install command, or server URL is available to configure yet.