Excalibur MCP

Sword-swift posting of pretty tweets to X (Twitter) via AI agents, monetized with Bitcoin Lightning micropayments through the DPYC(TM) Tollbooth protocol. Its 22 documented tools cover scheduler, snippet, tweet, posts. It is available as a remote MCP endpoint.

Teams that want a hosted social media endpoint instead of running a local process. The project is written in Python.

VERIFIED ACTIVE

LAST COMMIT 2026-08-24 · ★ 3 · #38 OF 46 MAINTAINED SOCIAL MEDIA · VERIFIED 2026-08-25

NOASSERTION · Python servers · how we verify → /methodology

01 · Install Excalibur MCP

Claude Code

claude mcp add lonniev-excalibur-mcp --transport http https://excalibur-mcp.fastmcp.app/mcp

Claude Desktop / Cursor / VS Code - add to config

{
  "mcpServers": {
    "lonniev-excalibur-mcp": {
      "url": "https://excalibur-mcp.fastmcp.app/mcp"
    }
  }
}

Same JSON for Cursor. For VS Code, rename the top-level key from `mcpServers` to `servers`.

Using another client? Same JSON, different key

Claude Desktop · mcpServers

Cursor · mcpServers

VS Code · servers

Windsurf · mcpServers

Zed · context_servers

Cline · mcpServers

Roo Code · mcpServers

Continue · mcpServers

LibreChat · mcpServers

Gemini CLI · mcpServers

Codex CLI · mcp_servers

Full setup guides: every client.

02 · Evidence

https://excalibur-mcp.fastmcp.app/mcp

transport: streamable-http

endpoint alive - responded to MCP initialize · probed 2026-08-25

Security posture

What to check before giving this server access to your agent - from the registry, GitHub, and our own probes. We don't score safety; we show what's verifiable.

runs as remote - your agent's requests go to excalibur-mcp.fastmcp.app

endpoint auth accepted our unauthenticated MCP initialize - no credentials needed to connect

license no standard license detected - usage rights unclear; check the repo before commercial use

registry namespace io.github.lonniev is GitHub-verified and matches the repo owner

03 · What Excalibur MCP can do

Prose above is summarized from the project's README and registry record - no invented capabilities.

What you can build

With this server connected, an agent can post a text tweet with markdown-to-Unicode rich text formatting, post a tweet with a hero banner image (image URL or SVG rendered to PNG), fetch the connected X account's handle and name for this patron (free), and read one stored post by id (owner-scoped).

Capability map

Tools grouped from the project's README - what Excalibur MCP lets an agent do.

read & search

6 tools - e.g. Fetch the connected X account's handle and name for this patron (free); Read one stored post by id (owner-scoped); List your stored posts, server-side sorted, filtered, and paginated

get_x_profile · get_post · list_posts · list_snippets · get_voice · fetch_dynamic_block

Scheduler

4 tools - e.g. Read recent scheduler-tick outcomes; The scheduler's configuration and current status (free; any proven patron); What the scheduled-post cron Worker is waiting on (operator-only)

get_scheduler_log · scheduler_status · scheduler_pending · scheduler_check_now

Snippet

3 tools - e.g. Read one saved snippet by id; Save a reusable snippet (opening/footer/CTA); Delete a saved snippet (free, owner-scoped)

get_snippet · save_snippet · delete_snippet

Tweet

2 tools - e.g. Post a text tweet with markdown-to-Unicode rich text formatting; Post a tweet with a hero banner image (image URL or SVG rendered to PNG)

post_tweet · post_tweet_image

create & write

1 tool - e.g. Store a new post (draft or scheduled); returns its post_id

create_post

update

1 tool - e.g. Patch a stored post (doc, publish_at, recurrence, status)

update_post

delete

1 tool - e.g. Delete a stored post (soft delete by default)

delete_post

Save

1 tool - e.g. Save your per-npub writing Voice

save_voice

Latest releases

v0.40.1 · 2026-08-24

Security - track tollbooth-dpyc 0.88.1 (cryptography floor raised to >=49.0.0) · Picks up the SDK's fix for GHSA-m2h6-j472-rp4c: the X.509 verifier accepted · wildcard DNS SANs, escaping permittedSubtrees. The advisory…

v0.40.0 · 2026-08-24

Fixed - A patron could see the scheduler was stuck, but not why, and could do nothing about it · A patron watching the Scheduler saw a red "Scheduler stalled" dot, no explanation, · and no move to make (#517).…

v0.39.0 · 2026-08-10

Added - the Performance page answers questions instead of listing numbers · Tier 1 rates and a time-of-day cohort, a continuous 24-hour local chart in place of a sparse · UTC table, a sortable posts-by-reach table…

04 · Who maintains Excalibur MCP

excalibur-mcp is maintained by lonniev. We track 13 MCP servers from lonniev - 13 actively maintained, 6 combined GitHub stars, oldest repo from Feb 2026. Full record: all servers from lonniev.

  1. personalbrain-mcp FastMCP server for TheBrain API - AI access to a personal knowledge graph, Tollbooth-monetized ★ 3

05 · Facts

category
social media - ranked #38 of 46 actively-maintained social media servers as of 2026-08-25.
release cadence
10+ releases in the last 90 days (latest 2026-08-24)
registry
io.github.lonniev/excalibur-mcp (active, first published 2026-07-16 · 11 versions)

06 · Excalibur MCP FAQ

Is Excalibur MCP still maintained?

Yes - as of 2026-08-25, its last commit was 2026-08-24 and it shipped 10+ releases in the last 90 days. We re-verify nightly.

What can Excalibur MCP do?

With this server connected, an agent can post a text tweet with markdown-to-Unicode rich text formatting, post a tweet with a hero banner image (image URL or SVG rendered to PNG), fetch the connected X account's handle and name for this patron (free), and read one stored post by id (owner-scoped).

How do I install Excalibur MCP?

Run `claude mcp add lonniev-excalibur-mcp --transport http https://excalibur-mcp.fastmcp.app/mcp`. You can also paste the ready-made client config above.

Does Excalibur MCP require authentication?

No - the endpoint accepted our unauthenticated MCP initialize when probed on 2026-08-25; you can connect without credentials.

07 · Alternatives to Excalibur MCP