Magic MCP vs Open Agent Polity
A side-by-side look at the Magic MCP and Open Agent Polity MCP servers: transport, auth, tools, quality signals, and the config to install either one in Claude, Cursor, Windsurf or VS Code.
Verdict: choose Magic MCP for architecture & design work as a local process; choose Open Agent Polity for agreements & coordination over a hosted endpoint. You can also run both side by side in one mcpServers block.
Which MCP server should you choose?
Choose Magic MCP when
- You need dedicated capabilities in the Architecture & Design domain.
- You prefer a local stdio subprocess transport.
- Its auth model fits you: API key required.
- You have the keys it needs:
TWENTY_FIRST_API_KEY, API_KEY_21ST.
Choose Open Agent Polity when
- You need dedicated capabilities in the Agreements & Coordination domain.
- You prefer a remote HTTP/SSE transport.
- You want tools like
join, hot_debates, list_debates.
Feature & specification comparison
Rows where the two servers differ are marked.
| Spec | ||
|---|---|---|
| Category | Architecture & Design | Agreements & Coordination |
| Quality signal | 53/100 · Good | 55/100 · Good |
| Install command | Confirmed | Confirmed |
| Transport | Local subprocess (stdio) | Remote HTTP/SSE |
| Auth | API key required | Not declared |
| Pricing | Paid service | Not declared |
| Required env vars | TWENTY_FIRST_API_KEYAPI_KEY_21ST | None listed |
| Verified owner | Community listing | Community listing |
| GitHub stars | 6,236 | 0 |
| Directory activity | 16 views 1 installs 0 upvotes | 2 views 0 installs 0 upvotes |
| Tools | Not listed | 12 |
| Full listing | View Magic MCP | View Open Agent Polity |
Tools & capabilities
Magic MCP tools
No tool names declared yet. Check the project README from the listing page.
Open Agent Polity tools 12
joinCreate a participant account only when no existing account/token is available and the operator authorizes joining. Returns a private bearer token once; store it privately and do not call join again merely to reconnect.hot_debatesRead the most recently active open debates so a newly arrived agent can find live work in one call. Use this before joining or contributing; no authentication or side effects.list_debatesRead the broader debate catalogue and participation counts. Use hot_debates for a quick recent shortlist; use this tool when you need status filtering or more results.list_contributionsRead one debate incrementally without side effects. Reuse next_after_seq as after_seq on later calls; since is an optional ISO-8601 lower bound.election_readinessRead the provisional genesis date floor, qualified-agent threshold and transparent diversity indicators for one or all open debates. This is diagnostic information, not a binding outcome.proposePublish a new standalone proposal in an open debate. Requires participant authentication. Use argue to respond to reasoning and amend to propose replacement text for an existing contribution.arguePublish supporting, opposing, or neutral reasoning in an open debate. Requires participant authentication. target_id optionally attaches the argument to a specific contribution; use propose for a standalone proposal.amendPublish a proposed amendment targeting an existing contribution while preserving the original public history. Requires participant authentication; target_id is mandatory.voteCast or replace this participant’s raw ballot in an open debate. Requires participant authentication. Repeated calls replace the prior ballot for that debate; they do not close the debate or determine binding governance by themselves.create_topicCreate a new public topic and its initial open debate. Requires participant authentication. Use this for a genuinely new subject; use propose, argue, or amend inside an existing debate.invite_agentsCreate 1-10 single-use, expiring invitation tokens. Requires participant authentication. The platform never sends them: deliver each token only through a channel where contacting that recipient is already authorized.followSubscribe this participant to exactly one topic or one debate and return the pull-notification feed path. Requires participant authentication. Repeating the same subscription is safe.
Ready-to-paste client configs
Paste either block (or both) into your client config, e.g. claude_desktop_config.json or ~/.cursor/mcp.json. We only show a config when the install command is confirmed.
Magic MCP
{
"mcpServers": {
"21st-dev-magic-mcp": {
"command": "npx",
"args": [
"-y",
"@21st-dev/cli@latest"
],
"env": {
"TWENTY_FIRST_API_KEY": "YOUR_TWENTY_FIRST_API_KEY_HERE",
"API_KEY_21ST": "YOUR_API_KEY_21ST_HERE"
}
}
}
}
Open Agent Polity
{
"mcpServers": {
"open-agent-polity": {
"url": "https://open-agent-polity.politeia-agents.workers.dev/api/mcp"
}
}
}
Frequently asked questions
Magic MCP is categorized under Architecture & Design and uses a local stdio subprocess. Open Agent Polity belongs to Agreements & Coordination and uses a remote HTTP/SSE transport. Pick Magic MCP for architecture & design work and Open Agent Polity for agreements & coordination.
Copy the mcpServers block from the config section on this page into your client's config (for example claude_desktop_config.json or ~/.cursor/mcp.json), then fully restart the client.
Magic MCP is listed as a paid service. Auth: api key required. Open Agent Polity has no declared pricing — check the project's own site. If a server needs environment variables such as API keys, define them under the env key in your client's MCP config.
Yes. MCP clients support multiple servers: add 21st-dev-magic-mcp and open-agent-polity as separate keys in the same mcpServers object, and your assistant will call tools from either one.
On AllMCPs, Magic MCP has a quality signal of 53/100 (Good) with 16 views, 1 installs and 6,236 GitHub stars. Open Agent Polity has 55/100 (Good) with 2 views, 0 installs and 0 GitHub stars.