WriteStack for Substack

WriteStack is a Substack creator platform. This skill teaches you how to use its MCP server to draft, schedule and review Notes and articles for the user. The skill carries no data of its own: everything comes from the user's own WriteStack account.

Requires a WriteStack account with MCP access enabled (https://www.writestack.io).

Connect the server (one time)

Check first whether the writestack MCP server is already configured: openclaw mcp doctor writestack --probe. If it is not, set it up:

1. Add it:

   openclaw mcp add writestack \
     --url https://www.writestack.io/api/mcp/mcp \
     --transport streamable-http
   

2. Turn on OAuth for it. In openclaw.json, under mcp.servers.writestack, add auth: "oauth".
3. Sign in with the user's WriteStack account: Settings → MCP → Sign in, or run openclaw mcp login writestack and follow the printed link.
4. Confirm: openclaw mcp doctor writestack --probe should list the tools.

Never ask the user to paste their password or an API key into chat. Sign-in happens on the WriteStack page that the link opens.

What you can do

Notes

• Read: list_notes, get_note, get_queue, get_schedule, get_next_available_slots, get_schedule_capacity, list_tags, list_activities
• Write: create_note, create_many_notes, update_note, schedule_notes, schedule_notes_with_custom_dates
• Style and performance: get_writing_style, get_notes_statistics, get_posts_statistics
• Cross-posting: list_buffer_channels (Buffer channels the user connected)

Articles

• Read: list_articles, get_article, list_article_newsletters, get_article_substack_status
• Write: create_article, update_article, generate_article, push_article_to_substack, schedule_article_on_substack, unschedule_article_on_substack

Other: get_feature_suggestion_link only returns the link to the WriteStack features board. It submits nothing. Use it when the user asks for something WriteStack cannot do, then tell them to post the idea there themselves.

The server does not delete notes or articles.

Rules to follow

1. Match the user's voice. Before writing new note content, call get_writing_style (unless the user pasted complete style instructions).
2. Notes are Markdown. Separate paragraphs with a blank line (two newlines).
3. Ask before assuming.
   • Tags: offer list_tags and ask which to apply before creating notes. Tags also decide which reserved queue times a note can take.
   • Links: if a note contains a link, ask whether the user wants a link-preview card. Pass includePreviews: true only if they say yes.
   • Buffer: call list_buffer_channels first if they want cross-posting.
4. Articles always need a newsletter. Call list_article_newsletters, show the user the options and ask which one to use before create_article, push_article_to_substack or schedule_article_on_substack. Never guess a publication ID.
5. Read an article before you edit it. Call get_article right before update_article, because the user may have changed it in WriteStack. update_article needs the baseVersion from that read and replaces the article's current content, so never update from an older copy. It saves in WriteStack only and does not push to Substack.
6. Pushing overwrites. Pushing an article that already has a Substack draft updates (overwrites) that draft. Say so before you do it.
7. Check capacity before scheduling notes. Always call get_schedule_capacity before schedule_notes or schedule_notes_with_custom_dates, and never schedule more notes than remaining unless unlimited is true. Use get_next_available_slots to preview when notes would land.
8. Prefer the recurring schedule. schedule_notes places notes in the user's next slots from their recurring schedule template and respects tag lanes. Use schedule_notes_with_custom_dates only when the user asked for specific dates and times, or has no schedule template yet. Dates must be in the future (ISO 8601).
9. Confirm before anything that publishes or schedules. Summarize what will be scheduled (how many, when) and wait for a clear yes.
10. Keep it private. Everything returned is the user's own data. Do not quote their notes or stats outside this conversation.

Example requests

• "Write 5 Notes about my latest article in my writing style and schedule them over the next week."
• "How did my Notes perform this month? Which ones got the most engagement?"
• "Generate a draft article about and push it to Substack as a draft."
• "What does my posting queue look like for the coming days?"

Troubleshooting

• Tools missing or sign-in fails: run openclaw mcp doctor writestack --probe, then openclaw mcp login writestack.
• Access denied: the account may not have MCP access enabled. Point the user to https://www.writestack.io/settings.
• Push or schedule queued instead of finishing: article pushes go through the user's Chrome extension, so they sync the next time WriteStack is open with the extension.