Spec Driven Development
MCP Server that facilitates spec-driven development workflows, not just Vibe Coding.
Description from the maker (original English)
Ask fifty verified people a five-second question and see what they think.
These three are never merged into one score: opinions, measurements and popularity are different things.
We have not written a plain-language summary for this one yet. Below are the facts we read from the registry.
Pick the AI app you use, then copy the settings.
FIFTYHEADS_API_KEY, AuthorizationValues marked secret are keys to your account. Never share them or paste them into a chat.
You need
Which app do you use?
Pick your app above. We remember it, so next time the button says “Install in …”.
This address needs a key in a request header, which the add-connector menu cannot set. Use Claude Code, Cursor or VS Code instead.
Open Claude Desktop → Settings → Developer → Edit Config, and paste this into claude_desktop_config.json
{
"mcpServers": {
"50heads": {
"command": "npx",
"args": [
"-y",
"@50heads/mcp"
],
"env": {
"FIFTYHEADS_API_KEY": "your-value"
}
}
}
}Run this in your terminal
claude mcp add --transport http 50heads https://mcp.50heads.com/mcp --header 'Authorization: your-value'claude mcp add 50heads --env FIFTYHEADS_API_KEY=your-value -- npx -y @50heads/mcpFill in the empty values before running it.
Paste into .cursor/mcp.json in your project, or ~/.cursor/mcp.json
{
"mcpServers": {
"50heads": {
"url": "https://mcp.50heads.com/mcp",
"headers": {
"Authorization": "your-value"
}
}
}
}Paste into .cursor/mcp.json in your project, or ~/.cursor/mcp.json
{
"mcpServers": {
"50heads": {
"command": "npx",
"args": [
"-y",
"@50heads/mcp"
],
"env": {
"FIFTYHEADS_API_KEY": "your-value"
}
}
}
}Your browser asks to open the app, then the app shows the settings and asks you to confirm. Key values are left empty for you to fill in.
Paste into .vscode/mcp.json in your project
{
"servers": {
"50heads": {
"type": "http",
"url": "https://mcp.50heads.com/mcp",
"headers": {
"Authorization": "your-value"
}
}
}
}Paste into .vscode/mcp.json in your project
{
"servers": {
"50heads": {
"type": "stdio",
"command": "npx",
"args": [
"-y",
"@50heads/mcp"
],
"env": {
"FIFTYHEADS_API_KEY": "your-value"
}
}
}
}Your browser asks to open the app, then the app shows the settings and asks you to confirm. Key values are left empty for you to fill in.
This address needs a key in a request header, which the add-connector menu cannot set. Use Claude Code, Cursor or VS Code instead.
Your choice stays on this device in a cookie; no account needed.
Authorization secret HTTP headerThese settings are generated from the maker’s registry entry. If the README says otherwise, follow the README.
We have not read this server’s tool list yet; we check endpoints in rotation.
We check information anyone can see; we have not read the code. Checks that do not apply are left out of the count. · Checked Nov 7, 2026
The registry name was verified against the domain 50heads.com (the registry checks domain ownership)
We have not read this repo from GitHub yet
We have not read this repo from GitHub yet
Not checked yet; we check endpoints in rotation
Not checked yet; we check endpoints in rotation
Not checked yet; we read the tool list when we check the endpoint
Compared with every active server in this category in the registry. Stars count only when the publisher owns the repo.
It passed 1 of 1 applicable basic checks. We have not read the code. Before adding a key or token, see what access the server asks for and use a key with only the permissions you need.
You need to fill in: FIFTYHEADS_API_KEY, Authorization
Either way works: install it on your computer or connect to the cloud version.
The GitHub repo last changed –, and the latest version (2026.1013.2) reached the registry 25 days ago.
Apps that support MCP, such as Claude Desktop, Claude Code, Cursor and VS Code. It connects by URL, so apps that accept remote MCP servers work too, such as ChatGPT in developer mode.
In the same category: Spec Driven Development, Remote Desktop Commander, 御府和田玉 在售作品查询
Servers in the same category from other makers, sorted by stars.
Reading a card:★ GitHub starsiThree pillars: reviews · checks · usageiUpdated = latest version published to the registryi
MCP Server that facilitates spec-driven development workflows, not just Vibe Coding.
Remote Desktop Commander: use files, terminal and processes on your own computers from any AI app.
Live in-stock Hetian jade from Yufu, Shanghai: prices, monthly price guide, book a viewing.
Copied from the maker’s repo as written. PopNx MCP has not reviewed or endorsed it. HTML, images and scripts are removed. Links lead off this site.
Ask fifty verified people a five-second question from Claude, ChatGPT, Cursor or your own agent, and see what they think. 50 answers at Tier 1: 1000 credits, priced in your account's currency.
There are two ways in, with the same tools:
https://mcp.50heads.com/mcp. Streamable HTTP, sign in with OAuth in the browser. Nothing to install.npx -y @50heads/mcp, a stdio server for hosts that launch a command. Needs Node 20 or later and an API key (or a one-time login).Pick your host below. The hosted server needs nothing installed: add the URL and sign in with OAuth in the browser, which also sets the connection's daily spend cap. The local server (npx -y @50heads/mcp) needs Node 20 or later and an API key.
Make an API key, if you need one, on the Developers page of the dashboard: https://50heads.com/app/developers. Keys start fh_live_ and are shown once. Or run npx -y @50heads/mcp login once and leave the key out.
npx -y @50heads/mcp config [host] prints any of these. The same instructions are on https://50heads.com/en-us/docs/mcp.
Hosted, sign in with OAuth. Settings, Connectors, Add custom connector. Paste the URL and sign in when asked. On Team and Enterprise plans an owner adds it for the organization first.
https://mcp.50heads.com/mcp
Or with an API key, in claude_desktop_config.json (macOS: ~/Library/Application Support/Claude/, Windows: %APPDATA%\Claude\).
{
"mcpServers": { "50heads": { "command": "npx", "args": [ "-y", "@50heads/mcp" ], "env": { "FIFTYHEADS_API_KEY": "fh_live_…" } } } }
Hosted, sign in with OAuth. Run in a terminal, then /mcp in Claude Code to sign in.
claude mcp add --transport http 50heads https://mcp.50heads.com/mcp
Or with an API key (CI and scripts):
claude mcp add --transport http 50heads https://mcp.50heads.com/mcp --header "Authorization: Bearer fh_live_…"
Hosted, sign in with OAuth. ~/.cursor/mcp.json (or .cursor/mcp.json in a project). Cursor opens the sign-in page.
{
"mcpServers": { "50heads": { "url": "https://mcp.50heads.com/mcp" } } }
Or with an API key:
{
"mcpServers": { "50heads": { "url": "https://mcp.50heads.com/mcp", "headers": { "Authorization": "Bearer fh_live_…" } } } }
Hosted, sign in with OAuth. Settings, Apps and Connectors, Advanced settings, turn on Developer mode, then Create. Paste the URL and choose OAuth. On Business and Enterprise plans an admin turns on Developer mode first.
https://mcp.50heads.com/mcp
Hosted, sign in with OAuth. .vscode/mcp.json in the workspace, or MCP: Add Server from the command palette.
{
"servers": { "50heads": { "type": "http", "url": "https://mcp.50heads.com/mcp" } } }
Or from a terminal:
code --add-mcp '{"name":"50heads","type":"http","url":"https://mcp.50heads.com/mcp"}'
Local, with an API key. ~/.codeium/windsurf/mcp_config.json, or Windsurf Settings, Cascade, MCP servers, View raw config.
{
"mcpServers": { "50heads": { "command": "npx", "args": [ "-y", "@50heads/mcp" ], "env": { "FIFTYHEADS_API_KEY": "fh_live_…" } } } }
Or the hosted server with an API key:
{
"mcpServers": { "50heads": { "serverUrl": "https://mcp.50heads.com/mcp", "headers": { "Authorization": "Bearer fh_live_…" } } } }
Local, with an API key. Hosts that launch a local command. Needs Node 20 or later and an API key from the dashboard.
FIFTYHEADS_API_KEY=fh_live_… npx -y @50heads/mcp
Hosts that speak Streamable HTTP: https://mcp.50heads.com/mcp with the header "Authorization: Bearer fh_live_…", or OAuth.
{
"mcpServers": { "50heads": { "url": "https://mcp.50heads.com/mcp", "headers": { "Authorization": "Bearer fh_live_…" } } } }
Ask your host to "use 50heads to estimate asking fifty people which of two names they prefer". estimate (action quote) is free and never spends credits. In Claude Code, /mcp lists the server and its tools; elsewhere, look for 50heads in the host's tools or connectors list.
npx -y @50heads/mcp login # opens the browser; the token goes in your keychain
npx -y @50heads/mcp status npx -y @50heads/mcp logout
login uses the OAuth device flow against https://auth.50heads.com. Tokens are kept in the macOS Keychain or the Secret Service on Linux, else in ~/.config/50heads/credentials.json (mode 600). An API key in FIFTYHEADS_API_KEY wins when both are present.
--proxy forwards stdio to the hosted server instead of running the tools locally.
| Variable | Meaning |
|---|---|
FIFTYHEADS_API_KEY | API key for CI and scripts |
FIFTYHEADS_API_URL | API base, default https://api.50heads.com |
FIFTYHEADS_MCP_URL | Hosted endpoint for --proxy |
FIFTYHEADS_AUTH_URL | Sign-in server for login |
FIFTYHEADS_CREDENTIALS_STORE=file | Keep the sign-in in a file, not the keychain |
FIFTYHEADS_DEBUG=1 | Log each call to stderr (never question text) |
action)There are nine tools, never more than ten. Each tool takes an action and that action's own arguments, validated per action (the input is a discriminated union on action), and tools/list documents every action in the tool's description. Scopes belong to actions, not tools: a connection that lacks the scope for an action is refused with insufficient_scope for that action alone, and a read-only grant never reaches an action that changes something. Tool annotations are true of every action in the tool: estimate, results, organization and audit are read-only (readOnlyHint: true); questions, projects and webhooks each hold a cancel or delete, so they carry destructiveHint: true; ask and help change something but destroy nothing. Each tool's _meta["com.50heads/scopes"] lists the scope of each action.
| Tool | Hints | Actions | Does |
|---|---|---|---|
estimate | read-only | quote, balance, templates, audiences, targeting | Price a question, check credits, and look up what you can ask for. |
ask | writes | ask, set, upload_image, build_link | Ask heads or your own audience, upload an image, build a link for a person to press Ask. |
results | read-only | get, wait, answers, export, list | Read results, wait for them, read single answers, export files, list your questions. |
questions | destructive | cancel, add_heads, flag_answer, file | Change one question: cancel it, add heads, flag an answer, file it. |
projects | destructive | list, create, update, delete, labels | Projects and labels that keep questions findable. |
webhooks | destructive | list, create, update, rotate_secret, test, deliveries, events, replay, delete | Webhook endpoints, deliveries and recent events. |
organization | read-only | get, domains, scim, member_sessions, service_accounts, apps | The organization, its domains, SCIM, member sessions, service accounts and workspace apps. |
audit | read-only | list, export | The organization audit log. |
help | writes | search, feedback, status, whoami | Search the help center, send feedback, check whether 50heads is working, see who the connection acts as. |
| Tool | Action | Scope | Does |
|---|---|---|---|
estimate | quote | questions:write | Price and fixes for a question. Never spends. Call it first. |
estimate | balance | account:read | Credits, reserved credits and what is left under the connection's daily cap. |
estimate | templates | none | Fixed-price templates. Works without signing in. |
estimate | audiences | none | Interest audiences you can ask instead of targeting, with prices by grade. |
estimate | targeting | none | Countries, languages, pool bands and the tags you can target. |
ask | ask | questions:write | Asks verified heads. Needs a fresh UUID as idempotency_key. Returns a task (or a question_id on older hosts). |
ask | set | questions:write | Two to ten questions for your own audience behind one shared link, answered in order. Needs an idempotency_key. |
ask | upload_image | questions:write | Puts an image into 50heads from base64 or an https link; returns an image_url for a question. |
ask | build_link | none | A portal link with the question filled in, for a person to check and ask. Spends nothing. |
results | get | questions:read | Results so far, without waiting: the share per option, a go or no go verdict against your own line on yes/no questions, and who beats whom on rankings and pairwise questions, with ranges. |
results | wait | questions:read | Waits up to 600 s on the server for the answers (min_answers, timeout_seconds). For hosts without tasks. |
results | answers | questions:read | Individual answers a page at a time, filtered by option, tier, country, age band or keyword. |
results | export | questions:read | The results as a file: CSV, JSON lines (one answer per line, with option indexes and the cohort hash), a one-page PDF report, or a PNG chart. |
results | list | questions:read | Your recent questions, filtered by status, project, label, reference, bookmark or set. Check before asking again. |
questions | cancel | questions:write | Stops a live question and refunds unanswered heads. Destructive. |
questions | add_heads | questions:write | More heads on the same question, merged into the same result. Needs an idempotency_key. |
questions | flag_answer | questions:write | Reports one answer by its attestation_ref for review; upheld flags are refunded. |
questions | file | questions:write | Files a question: project, labels, bookmark, archive, and an external reference set once. |
projects | list | questions:read | Projects in the account, with include_archived for archived ones too. |
projects | create | questions:write | A new project to file questions in. |
projects | update | questions:write | Renames, redescribes, archives or restores a project. |
projects | delete | questions:write | Deletes a project. Its questions stay, with their answers, outside any project. Destructive. |
projects | labels | questions:read | Labels in use, most used first. |
webhooks | list | webhooks:read | Webhook endpoints: address, events, filter, on or off, last delivery. Secrets masked. |
webhooks | create | webhooks:write | Sends the chosen events, signed, to an https address you own; filter by project or label. Returns the secret once. |
webhooks | update | webhooks:write | Changes address, events, description or filter (null clears it); pauses or resumes. |
webhooks | rotate_secret | webhooks:write | A new secret, returned once; the old one keeps signing for overlap_hours (default 24, up to 168). |
webhooks | test | webhooks:write | Sends a signed webhook.test event now and says how the receiver answered. |
webhooks | deliveries | webhooks:read | The latest 100 deliveries, by endpoint or state (failed is out of retries). |
| webhooks | events | `webh
Only the beginning is shown; read the rest in the repo