Spec Driven Development
by formulahendry
MCP Server that facilitates spec-driven development workflows, not just Vibe Coding.
Runs on your computer★ 440MITUpdated 14 months ago
Install
Databutler
Overview
Description from the maker (original English)
Verified facts for AI agents: rates, exams, recalls, holidays, and what changed since your cutoff.
PopNx MCP’s three pillars
These three are never merged into one score: opinions, measurements and popularity are different things.
- User voiceiNo reviews yetReviews open together with accounts in a later step
- Our basic checksi1 of 1 passedChecked from public information; code not scanned yet
- UsageiNot measured yet★ –
What you can do with it
We have not written a plain-language summary for this one yet. Below are the facts we read from the registry.
- Connection: Runs in the cloud
- Transport: Streamable HTTP
- Category: Other
Install
Pick the AI app you use, then copy the settings.
Before you install
- Basic checks: 1 of 1 passed
- Runs on the maker’s server: what you ask it goes through their server.
- The registry lists no key to fill in.
You need
- Runs in the cloudNothing to install; it connects over the internet
Which app do you use?
Pick your app above. We remember it, so next time the button says “Install in …”.
Works in Claude on the web, desktop and mobile:
- Open Settings → Connectors
- Press Add custom connector
- Paste the address below and press Add
- If it asks you to sign in, sign in with the maker
https://databutler.dev/api/mcpRun this in your terminal
claude mcp add --transport http databutler https://databutler.dev/api/mcpOr copy the settings yourself
Paste into .cursor/mcp.json in your project, or ~/.cursor/mcp.json
{
"mcpServers": {
"databutler": {
"url": "https://databutler.dev/api/mcp"
}
}
}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.
Or copy the settings yourself
Paste into .vscode/mcp.json in your project
{
"servers": {
"databutler": {
"type": "http",
"url": "https://databutler.dev/api/mcp"
}
}
}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.
ChatGPT connects only to servers on the internet:
- Open ChatGPT on the web → Settings → Connectors (Apps)
- Press Create or Add (some plans need Developer mode under Advanced first)
- Paste the address below, give it a name and save
- If it asks you to sign in, sign in with the maker
https://databutler.dev/api/mcpMenu names can differ slightly by plan and over time.
Your choice stays on this device in a cookie; no account needed.
These settings are generated from the maker’s registry entry. If the README says otherwise, follow the README.
What it can do
We have not read this server’s tool list yet; we check endpoints in rotation.
Basic checksi
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
- ✓ Pass
Maker matches the repo
The registry name was verified with the GitHub account physics-star-cat, which owns the repo
- … Not checked yet
Still maintained
We have not read this repo from GitHub yet
- … Not checked yet
Has a licence
We have not read this repo from GitHub yet
- … Not checked yet
Endpoint responds
Not checked yet; we check endpoints in rotation
- … Not checked yet
Sign-in with OAuth
Not checked yet; we check endpoints in rotation
- … Not checked yet
No hidden instructions in tool descriptions
Not checked yet; we read the tool list when we check the endpoint
Compared with others in Otheri
- More stars than 0% of the other 32572 servers in this category
- Published to the registry more recently than 55% of the other 32572 servers in this category
- Basic checks equal to or better than 100% of the other 32572 servers in this category
Compared with every active server in this category in the registry. Stars count only when the publisher owns the repo.
Common questions
Is Databutler safe?
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.
What keys or codes does it need?
The registry does not list a required key, though some servers ask you to sign in on first use.
Does it run on my computer or in the cloud?
It runs in the maker’s cloud. Connect over the internet with nothing to install, but what you send passes through the maker’s servers.
Is it still maintained?
The GitHub repo last changed –, and the latest version (1.0.0) reached the registry 33 days ago.
Which apps can use it?
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.
What can I use instead?
In the same category: Spec Driven Development, Remote Desktop Commander, AvaHR
Alternatives
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
Remote Desktop Commander
by desktop-commander
Remote Desktop Commander: use files, terminal and processes on your own computers from any AI app.
Runs in the cloud★ 211Updated yesterday
Install
AvaHR
by avahr.com
Read hiring data and create inactive assessment and questionnaire drafts for human review.
Runs in the cloudUpdated today
Install
README from the maker
Open the README
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.
Data Butler (databutler.dev)
An agent honeypot: clean, verified UK public data served to AI agents via MCP and REST. Not an SEO play — no GSC ambitions. The customer is an AI assistant answering a human's question; the product is being the source that is *right*, with provenance on every number.
- Planned domain: databutler.dev (until purchased/connected, the Vercel default
databutler.vercel.appworks, but registry listings must NOT be published until the final domain is live — listings bake in URLs). - Status: LIVE (launched 2026-08-31): https://databutler.dev — REST + MCP serving, domain attached, listed on Smithery (drchriseames/databutler-uk-exams, -uk-rates) and the official MCP Registry (io.github.physics-star-cat/databutler-uk-exams, -uk-rates). Tracking LIVE (GA4 property 552213153, verified in realtime; monitored by webmon 🤖 column). PulseMCP will auto-ingest from the official registry. Front door
POST /api/mcp— built 2026-09-01 on branch feat/front-door; listing asio.github.physics-star-cat/databutler/ Smitherydrchriseames/databutlerpending deploy. - Born 2026-08-31 out of the agent-API work on whatbreaks.uk (MOT data) and lowriskquotes.com (Monte Carlo) — full history in
../docs/AUDIT_2026-08-30_five-sites.md§3b–3e and../docs/MONETISATION-DECISION.md.
The model (one brand, many focused servers)
There is no domain authority in MCP registries — discovery is per-listing. So this is NOT one mega-server (tool-list bloat kills those); it is one domain/repo/brand hosting separate, focused MCP endpoints, each listed individually under one namespace, cross-referencing each other:
Front door (2026-09): POST /api/mcp lists the five high-frequency tools directly plus what_changed_since, coverage, catalogue, call. It is still not a mega-server — everything else stays behind call, capped at 9 listed tools by test. Since 2026-10-31 the Vercel firewall answers 403 for every focused server except /api/mcp/facts and /api/mcp/uk-rates: point clients at the front door, whose call runs any tool by name.
The roadmap is ordered by (value to an AI agent) × (likelihood we can build it well). It deliberately includes the maintainer-Claude wishlist — this product is designed with Claude as the end user, by Claude:
| # | Vertical (wishlist item it serves) | Endpoint | Status |
|---|---|---|---|
| 1 | UK rates & thresholds — the "is this still true?" fact-refresh server for the numbers agents misquote most (wishlist #1) | /api/mcp/uk-rates | v1 — LIVE |
| 2 | UK exams — boards, specs, topic→paper ("is electricity paper 2 AQA"), past-paper index (unique curation edge: maintainer taught) | front door call (/api/mcp/uk-exams: 403 since 2026-10-31) | v1 — LIVE |
| 3 | Provenance checker — "who really runs this domain/package?" (wishlist #2) — live RDAP/npm/PyPI, homoglyph-aware typosquat | front door call (/api/mcp/provenance: 403 since 2026-10-31) | v1 — LIVE |
| 4 | Stats toolkit — exact statistics & probability (Claude's maths pick) — distributions, hypothesis tests, CIs, Bayes, regression; reference-validated | front door call (/api/mcp/stats: 403 since 2026-10-31) | v1 — LIVE |
| 5 | Vehicles hub — UK MOT failure data (live proxy to whatbreaks.uk), UK safety recalls (DVSA, 4,876 recalls since 2016), French recalls (RappelConso, 1,663 fiches), Japanese recalls + owner complaints (MLIT, 75 models); EU Safety Gate stub | front door call (/api/mcp/vehicles: 403 since 2026-10-31) | v1 — built 2026-10-03 |
| 6 | Take-home pay — take_home_pay for us, uk, ca, au, in, br, de, fr, pl, es: live proxy to the LifeByNumbers salary calculators (same operator), uniform shape (gross/net/deductions annual + monthly, typed breakdown, taxYear, assumptions). Listed at the front door — the highest-frequency money question after rates | front door call (/api/mcp/tax: 403 since 2026-10-31) | v1 — built 2026-10-03 |
| 7 | Software end-of-life — "is this version still supported, and until when" for the 14 runtimes/OSes agents are asked about most (Node.js, Python, Ubuntu, Debian, Android, iOS, macOS, Windows, Oracle JDK, Go, Ruby, PHP, PostgreSQL, React): committed monthly snapshot of endoflife.date open data (MIT, 340 cycles), version → cycle resolution, days remaining/since, changelog entries when a cycle reaches EOL or a date moves | front door call (/api/mcp/software-eol: 403 since 2026-10-31) | v1 — built 2026-10-03 |
| 8 | Policy rates — policy_rate: the three most-asked central-bank rates (BoE Bank Rate, Fed federal funds target range, ECB key rates) as committed, changelogged, source-watched data; the first global step of the "is this still true?" layer (#9, #12). Freshness due after 45 days; eight decisions a year each | front door call (/api/mcp/policy-rates: 403 since 2026-10-31) | v1 — built 2026-10-03 |
| 9 | US federal rates & thresholds — us_rates_lookup: tax year 2026 income-tax schedules and standard deduction, Social Security wage base, Medicare, retirement-plan/IRA, HSA and estate-gift figures read from the IRS revenue procedures, notices and SSA's Federal Register notice, each with the quoted sentence and prior-year value (wishlist #12, "Rates, country #2 = US"); first country after the UK on the "is this still true?" layer | front door call (/api/mcp/us-rates: 403 since 2026-10-31) | v1 — built 2026-10-03 |
| 10 | German rates & thresholds — de_rates_lookup: Veranlagungszeitraum 2026 Einkommensteuertarif (§ 32a) and Solidaritätszuschlag, Sozialversicherung Beitragsbemessungsgrenzen, Rechengrößen and Beitragssätze, Mindestlohn (2026 and the fixed 2027 step), Geringfügigkeitsgrenze, Kindergeld, Kinderfreibetrag, Pauschbeträge, Entfernungspauschale and the Umsatzsteuer rates (§ 12 UStG), read from the consolidated statutes and the Bundesgesetzblatt with German term + English label, quoted sentence and prior value; country #3 on the "is this still true?" layer | front door call (/api/mcp/de-rates: 403 since 2026-10-31) | v1 — built 2026-10-03 |
| 11 | UK vehicle tax (VED) and MOT rules — uk_vehicle_rules_lookup: the car-tax and MOT numbers the four car sites' users ask about and that change every 1 April (first-year CO2 bands, standard rate, expensive car supplement incl. the £50,000 EV threshold, 2001–2017 bands, pre-2001 rates, electric-car rules, historic 40-year exemptions, MOT fees/retests/penalties), each with the quoted gov.uk line and its 2025-26 value; calendar-driven refresh | front door call (/api/mcp/uk-vehicle-rules: 403 since 2026-10-31) | v1 — built 2026-10-04 |
| 12 | UK exam dates and spec changes — results days, the summer 2027 timetable (JCQ window + the most-asked papers at AQA, Pearson Edexcel, Cambridge OCR and WJEC/Eduqas, all final), entry deadlines with each board's late-fee dates, Scotland's results day, announced spec changes; every date quoted from the JCQ/board/regulator document with the summer-2026 date as previous | front door call (/api/mcp/uk-exam-dates: 403 since 2026-10-31) | v1 — built 2026-10-04 |
| 13 | Calendar facts — the boring dates a training cutoff hides: public holidays for the UK (3 nations), US federal, Germany (16 Länder) and France (2 zones) from the official lists; tax-year starts/ends for 9 countries with the statute quoted; daylight-saving rules and computed switch dates for 6 countries — 2026–2028, monthly snapshot, changelog when a year is published or a holiday moves | front door call (/api/mcp/calendar: 403 since 2026-10-31) | v1 — built 2026-10-04 |
| 14 | UK government services — uk_gov_process: the gov.uk services assistants get wrong after a fee or rule change (passport fees UK/overseas, ETA fee and enforcement, driving licence renewal, SORN, voter registration, birth/death registration, Blue Badge, Self Assessment and Making Tax Digital, NI number, Universal Credit, EU Settlement Scheme, BRP → eVisa), each with the official start URL, the quoted gov.uk sentence and dated changes | front door call (/api/mcp/uk-gov-process: 403 since 2026-10-31) | v1 — built 2026-10-04 |
| 15 | Japan vehicle statutory costs — jp_vehicle_costs_lookup: the 法定費用 of a 車検 and the annual car taxes for the shakendata.com audience (自動車重量税 2026-05 – 2028-04 table and age rules, エコカー減税 bands, 自賠責 before and from 2026-11-01 as separate keys, 継続検査 fees from 2026-04-01 with the old amounts, 自動車税 by displacement, 軽自動車税), each with the Japanese term and the quoted official row; first non-Western country and the jp facts namespace | front door call (/api/mcp/jp-vehicle-costs: 403 since 2026-10-31) | v1 — built 2026-10-24 |
| 16 | Japan daily-life official figures — jp_living_costs_lookup: the figures a resident or employer in Japan looks up (地域別最低賃金 FY2026 for all 47 prefectures with their staggered 発効日 and FY2025 amounts, 協会けんぽ rates by prefecture with 介護 and 子ども・子育て支援金, 厚生年金 / 国民年金, 雇用保険料率, 児童手当, 出産育児一時金, 高額療養費 through the 2026 and 2027 revisions, 2027 祝日, 消費税, 基礎控除 / 給与所得控除, 住民税 均等割), each with the Japanese term and the quoted official row; prefecture figures are individual facts (jp/minimum-wage/tokyo) | front door call (/api/mcp/jp-living-costs: 403 since 2026-10-31) | v1 — built 2026-10-24 |
| 17 | UK inflation (CPI, CPIH) — the current ONS CPI and CPIH 12-month rates, CPI index and annual averages, each with its reference month, release day and series page | /api/mcp/uk-inflation | v1 — built 2026-10-31 |
| 18 | US inflation (CPI-U) — us_inflation_lookup: the BLS CPI-U 12-month percent change and index level for the latest month (with the prior month and the next release day) and the annual averages from 2021, fetched by scripts/us-inflation.js from the BLS API and release; Verified Facts us/cpi-u/* with a scheduled nextExpectedChange | /api/mcp/us-inflation | v1 — built 2026-10-31 |
Planned, parked and out of scope (hand-maintained — these are not area modules):
| # | Vertical (wishlist item it serves) | Endpoint | Status |
|---|---|---|---|
| 4 | Local-services resolver — postcode → council → services/MP (wishlist #3) | /api/mcp/uk-councils | phase 2 |
| 5 | Bin collection pilot (5–10 large councils, feasibility-gated) | — | phase 2b |
| 3c | Front door — single POST /api/mcp hub: direct high-frequency tools + what_changed_since (changelog vs. your training cutoff), coverage, catalogue/call; freshness + citation permalink on every response; weekly gov.uk source watcher (spec: docs/superpowers/specs/2026-09-01-front-door-design.md) | /api/mcp | built — deploy pending |
| 9 | Drift facts (global) — facts that move on a calendar and agents misquote: tax-year boundaries by country, public holidays, DST transitions, currency/country codes, headline VAT/sales-tax rates. Cheap to curate, low rot, feeds what_changed_since | /api/mcp/drift | after front door |
| 10 | Volatility tool — volatility(topic): how often a class of fact changes and when it last did, so an agent knows whether to trust memory at all. Curated table, no per-country data; Claude's own top pick for the global layer | front door tool | after front door |
| 11 | Provenance, widened — crates.io, RubyGems, Go modules, Docker Hub, GitHub Actions, browser extensions; then MCP-server provenance (cross-check a registry listing's claimed domain, repo and publisher — the hub that vets other hubs) | /api/mcp/provenance | after front door |
| 12c | Rates, further countries — AU/CA/IN sites 403 automated fetches (browser-only curation); US and Germany are built (roadmap above) | /api/ /rates | after the source watcher proves the annual loop on us-rates/de-rates |
| 13 | Exams, global boards — IB and AP: same topic→paper query stream, same teaching moat
Only the beginning is shown; read the rest in the repo