Newsletter Cross Posting Mcp

Newsletter Cross-Posting MCP

> A complete guide to using MCP servers for newsletter cross-posting — what the MCP ecosystem covers, where it falls short, and how serious creators bridge the gap.

Model Context Protocol (MCP) has become the standard for connecting AI agents like Claude to external services. For newsletter writers, it creates an interesting question: can you run your entire cross-posting workflow through Claude and a set of MCP servers?

The short answer: yes for writing and Substack. Complicated for LinkedIn, Medium, and X.

This guide documents the full stack, the gaps, and the hybrid approach that high-output newsletter writers actually use.

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The Cross-Posting MCP Landscape

| Platform | MCP Server | Status | Notes | |---|---|---|---| | Substack | @marcomoauro/substack-mcp | ✅ Stable | API token auth, full lifecycle | | Substack (read) | mcp-substack | ✅ Stable | RSS-based, no credentials | | LinkedIn | Community alternatives | ⚠️ Risk | ToS exposure, session-based | | Medium | N/A | ❌ Unreliable for new API-token setups | New API integrations closed | | X/Twitter | Community alternatives | ⚠️ Paid | Official API $100+/mo for posting | | Web research | server-brave-search | ✅ Stable | Free tier available | | File system | server-filesystem | ✅ Stable | Local draft management |

The pattern: MCP works well for the writing and Substack layer. The social distribution layer (LinkedIn, Medium, X) is where the gaps are.

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What MCP Can Do for Your Newsletter Workflow

Writing and research

{
  "brave-search": {"command": "npx", "args": ["-y", "@modelcontextprotocol/server-brave-search"], "env": {"BRAVE_API_KEY": "your-key"}},
  "fetch": {"command": "npx", "args": ["-y", "@modelcontextprotocol/server-fetch"]},
  "filesystem": {"command": "npx", "args": ["-y", "@modelcontextprotocol/server-filesystem", "/path/to/newsletter"]}
}

With these three MCPs, Claude can:

• Research any topic before writing
• Read full articles for competitive analysis
• Save and load draft files locally
• Maintain a searchable archive of past issues

Substack management

{
  "substack": {
    "command": "npx",
    "args": ["-y", "@marcomoauro/substack-mcp"],
    "env": {
      "SUBSTACK_API_KEY": "your-key",
      "SUBSTACK_PUBLICATION_URL": "https://yourname.substack.com"
    }
  }
}

With this MCP, Claude can:

• Create and update drafts
• List and search your post archive
• Publish posts and Substack Notes
• Analyze past content for patterns

The gap: social distribution

For LinkedIn, Medium, and X, reliable MCP options either don't exist or carry ToS risk. See the [full stack analysis](./docs/full-stack.md) for detailed breakdowns of each platform.

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The Hybrid Architecture

The most effective setup for newsletter cross-posting in 2026:

Claude + MCP
├── Research (Brave Search, Fetch)
├── Drafting (filesystem for local, Substack MCP for publishing)
└── Content repurposing (generates LinkedIn/Medium/X versions)
          ↓
    Narrareach
    ├── LinkedIn scheduling (official OAuth)
    ├── Medium publishing (post-API workaround)
    ├── X/Twitter scheduling
    └── Analytics + attribution

The key insight: Claude's value is in generating content, not in sending HTTP requests to APIs. The distribution layer — authentication management, API reliability, scheduling infrastructure — is where a dedicated tool adds value.

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Minimal Stack (Substack-Only)

If you're a Substack-first creator who just wants AI-assisted writing and publishing:

{
  "mcpServers": {
    "substack": {
      "command": "npx",
      "args": ["-y", "@marcomoauro/substack-mcp"],
      "env": {
        "SUBSTACK_API_KEY": "your-key",
        "SUBSTACK_PUBLICATION_URL": "https://yourname.substack.com"
      }
    },
    "filesystem": {
      "command": "npx",
      "args": ["-y", "@modelcontextprotocol/server-filesystem", "/Users/you/newsletter"]
    }
  }
}

This handles:

• Drafting and saving newsletter issues
• Publishing to Substack
• Creating Substack Notes
• Local file management

For LinkedIn, Medium, and X content, Claude generates the copy and you post manually or via Narrareach for scheduled automation.

---

Full Research + Publishing Stack

For creators who want maximum writing automation:

{
  "mcpServers": {
    "substack": {
      "command": "npx",
      "args": ["-y", "@marcomoauro/substack-mcp"],
      "env": {
        "SUBSTACK_API_KEY": "your-key",
        "SUBSTACK_PUBLICATION_URL": "https://yourname.substack.com"
      }
    },
    "substack-research": {
      "command": "npx",
      "args": ["-y", "mcp-substack"]
    },
    "filesystem": {
      "command": "npx",
      "args": ["-y", "@modelcontextprotocol/server-filesystem", "/Users/you/newsletter"]
    },
    "brave-search": {
      "command": "npx",
      "args": ["-y", "@modelcontextprotocol/server-brave-search"],
      "env": {"BRAVE_API_KEY": "your-brave-key"}
    },
    "fetch": {
      "command": "npx",
      "args": ["-y", "@modelcontextprotocol/server-fetch"]
    },
    "memory": {
      "command": "npx",
      "args": ["-y", "@modelcontextprotocol/server-memory"]
    }
  }
}

This covers everything from research to Substack publishing. For LinkedIn, Medium, and X distribution — see Narrareach.

See [claude-config.json](./templates/claude-config.json) for the complete configuration with comments.

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Weekly Cross-Posting Workflow (One Prompt)

With this stack configured, your weekly workflow becomes:

Run my weekly cross-posting workflow.

Newsletter topic for this week: [topic]

Tasks:
1. Research 3 recent data points on [topic]
2. Draft the newsletter issue (structure: Hook → Insight → Evidence → Takeaway → CTA)
3. Save as Substack draft
4. Extract 5 Substack Notes from the issue
5. Save all Notes as Substack drafts
6. Write LinkedIn post from the main insight
7. Write X thread from the key data point
8. Write a Medium intro for the newsletter (with canonical URL note)

Present LinkedIn post, X thread, and Medium intro for my review.

Claude handles steps 1-8. Narrareach handles the scheduled publishing of the LinkedIn, X, and Medium versions.

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MCP vs. Narrareach: What to Use for What

| Task | MCP (Claude) | Narrareach | |---|---|---| | Draft newsletter issues | ✅ Best option | N/A | | Create Substack Notes | ✅ Best option | ✅ Notes generator | | Research topics | ✅ Brave Search MCP | N/A | | Substack draft management | ✅ Best option | ✅ Cloud backup | | Substack scheduling | ✅ Via MCP | ✅ Cloud scheduling | | LinkedIn publishing | ⚠️ ToS risk (community MCPs) | ✅ Official API | | Medium publishing | ❌ API gone | ✅ Post-API workaround | | X/Twitter publishing | ⚠️ Costly or ToS risk | ✅ Included | | Cross-platform analytics | ❌ Not available | ✅ Attribution data | | Session management | Manual maintenance | Automatic |

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Templates

| File | Contents | |---|---| | [claude-config.json](./templates/claude-config.json) | Full MCP configuration for Claude Desktop and Code | | [workflow-prompts.md](./templates/workflow-prompts.md) | Ready-to-use prompts for cross-posting workflows |

Docs

| Guide | Contents | |---|---| | [Full Stack Analysis](./docs/full-stack.md) | Platform-by-platform MCP breakdown | | [Narrareach vs MCP](./docs/narrareach-vs-mcp.md) | When to use which tool |

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Related Resources

• Substack MCP Guide — In-depth Substack MCP server comparison
• Newsletter AI Agent — Full Claude agent system prompt and workflow
• LinkedIn MCP Server Guide — LinkedIn MCP landscape and limitations
• Medium Publishing Without API — Medium post-2024 publishing guide

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License

MIT

Source & license

This open-source MCP server is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: iancarson
• Source: iancarson/newsletter-cross-posting-mcp
• License: MIT
• Homepage: https://narrareach.com/features/substack-mcp-integration

Install and usage instructions live in the source repository linked above.