Usaref MCP server

• Registry namedev.usaref/reference-dataverified in the MCP registry

The registry name sits under usaref.dev. The registry only lets a publisher use that namespace after proving control of the domain through DNS or HTTP.

• Stateanswerschecked 2026-10-20
• Tools32
• Server calls itselfusaref
• Server version1.0.0
• Protocol version2025-06-18

On 2026-10-20 the server answered initialize and tools/list without a sign-in. First answer in 328 ms.

• Answeredmeasuring1 of the 7 daily checks it takes to print a share
• Median first answer1220 ms
• Space in an agent's context≈ 12,306 tokensthe definitions of all its tools (32), which an agent carries on every turn
• Tool definitionsA · 99 of 100
• Typed results32 of 32 toolsdeclared outputSchema: results come typed, read once

• Parameters without a description: in 1 of 32

A program checks the server once a day: initialize and tools/list, no model. Tokens are the definitions' length at about four characters a token. The grade averages six checks of every tool's name, description, schema and annotations; it says how well the tools are described, not whether they work. The state of vendors' MCP servers: method and numbers →

• list_series

  FREE. Catalog of all usaref reference-data series: supported countries, series ids, descriptions, freshness metadata and per-series URLs. Call this first to discover what data exists. Paid answer tools accept receipt=true (included in the…

• get_public_holidays

  FREE. Official public-holiday calendar for a supported country, including gazetted movable holidays, with the official government source cited. Some countries also carry sub-national calendars (e.g. the German Laender): the `subdivisions`…

• get_public_holidays_worldwide

  FREE with any API key, including the free key by email (https://usaref.dev/free-key). Same as get_public_holidays, but for every country across all seven brands, not only North American. Unmetered: never counts against the key's…

• get_key_balance

  FREE. Remaining allowance for an API key (free, card or metered): plan, quota, used, remaining, reset date and what the key covers. Never metered. Pass api_key, or send the key as the X-API-Key header on /mcp.

• is_business_day

  FREE, unmetered. Is this date a business day in this country? Returns is_business_day, the reason (weekend, public_holiday, makeup_workday…), the holiday names, and the next and previous business day. Uses the country's national…

• add_business_days

  FREE, unmetered. The date n business days after (or, for negative n, before) a start date. The start date is day 0 and never counted; n = 0 returns the date itself if it is a business day, otherwise the next one. Lists every non-business…

• business_days_between

  FREE, unmetered. Business days between two dates. business_days counts (from, to] and is negative when to is before from, so add_business_days(from, business_days) lands on to whenever to is a business day; business_days_inclusive counts…

• get_series

  PAID ($0.003). Current value of a reference series — e.g. series=policy-rate, vat, minimum-wage. Every value carries its official source citation, effective date, last-confirmed date and staleness flag. Pass api_key if you have one…

• get_series_history

  PAID ($0.003). Historical values of a reference series with effective date ranges, optionally filtered by from/to (YYYY-MM-DD). Pass api_key if you have one (instant card checkout at /pricing); otherwise the response explains how to pay…

• get_filing_deadlines

  PAID ($0.003, same as any series). Recurring statutory tax deadlines for a country — VAT/GST returns and payments, PAYE/payroll withholding remittances, corporate income tax returns and provisional/instalment payments — as RULES, each…

• check_minimum_wage

  PAID ($0.02). Compliance verdict: is a salary at, above or below the country's statutory minimum wage? Returns verdict, margin, the statutory floor and the legal instrument it rests on. Honest statuses when no enforceable floor exists or…

• compute_vat

  PAID ($0.01). VAT breakdown for an amount: net, tax and gross using the country's current statutory rate, including per-levy components where the rate is composite (e.g. Ghana VAT + NHIL + GETFund). mode=add treats the amount as net…

• count_working_days

  PAID ($0.002). Working days in a date range for a country: weekends (Egypt's Fri–Sat handled) and statutory public holidays applied, with the holidays hit by name and the next working day after the range. Range max 366 days. Pass api_key…

• settlement_date

  PAID ($0.02). Settlement/value date: the date n business days after a trade date, computed on the INTERSECTION of the calendars you name, with a per-day trail showing every skipped day and why, on which calendar. Supply business_days for…

• compute_income_tax

  PAID ($0.02). Statutory income tax on a TAXABLE-income figure using the country's verified marginal bracket schedule, with full per-bracket workings, effective rate and marginal rate. You pass the amount in local currency. IMPORTANT: this…

• compute_statutory_interest

  PAID ($0.02). Simple statutory interest on a principal at the cited statutory-interest series rate: Actual/365 simple, principal × (rate/100) × (days/365). Pass days, or from and to as YYYY-MM-DD (from inclusive, to exclusive). If both…

• compute_employment_cost

  PAID ($0.05). Cost to employ: prices every statutory contribution on both the employee and employer sides for a gross salary, returning line-by-line amounts with instrument citations and an explicit refused list for schemes that could not…

• cost_hire

  PAID ($0.50). Cost this hire: one cited dossier for a salary - wage-floor verdict, employer and employee contributions (or PAYE net pay for NG/KE), employer cost, optional income tax on taxable_income and first working day on or after…

• charge_sale

  PAID ($0.50). Charge this sale: should this invoice carry VAT, which country's and how much - place of supply under the EU, UK and South Africa rules, net/VAT/gross, registration threshold, rule cited. Omit buyer_country for…

• charge_sale_certified

  PAID ($0.75). The charge_sale dossier plus an Ed25519-signed certified extract of the governing VAT rate, for a filing. Refused free when the governing source cannot be certified right now. Anything we cannot answer in full is refused…

• invoice_payable

  PAID ($0.40). Is this invoice overdue, by how many days, and how much statutory late-payment interest is owed (Actual/365 simple, rate and workings cited). Late-payment regime: none here; statutory interest only: BS, CA, CR, HN, MX, PA…

• evidence_pack

  PAID ($0.25). Country evidence pack: the full cited country brief plus up to 3 Ed25519-signed certified extracts (default the first certifiable of vat, policy-rate, minimum-wage). Named series must all be certifiable. Anything we cannot…

• hire_compare

  PAID ($0.75 for 2 countries, $1.00 for 3-5). Employer cost, employer and employee contributions, on-cost percent and wage-floor verdict side by side and ranked, every figure cited. Countries (any brand): AE, AU, CA, DE, ES, GB, IT, MX…

• next_filings

  PAID ($0.35). Upcoming VAT, PAYE and corporate-tax due dates in a window (default the next 90 days), rolled for weekends and national public holidays, each rule cited. Countries with verified rules here: CA, DO, US. Anything we cannot…

• verify_answer_receipt

  FREE. Verify an answer receipt (kind answer_receipt) with the Ed25519 public key only. Pass the receipt object or its canonical JSON, signature_value when the signature is not inside the receipt, and public_key_pem to verify offline. If…

• get_snapshot

  PAID ($0.02). Snapshot of every series for every country in one call. Pass api_key if you have one (instant card checkout at /pricing); otherwise the response explains how to pay via x402. Every US series is free to try. After a 200, bind…

• get_country_brief

  PAID ($0.01). Country brief: every reference series we hold for one country (policy rate, VAT/GST, CPI, taxes, minimum wage, holidays...) in one call, each with value, unit, effective and last-confirmed dates, official source and…

• compare_series

  PAID ($0.02). One series (e.g. vat, policy-rate, minimum-wage, corporate-tax) across up to 10 countries of this brand in one call; each row carries its own source, dates and labels, and countries without the series are listed under…

• validate_tax_id

  PAID ($0.003). Offline format and check-digit validation of a business tax ID or VAT number for one country of this brand: valid/invalid, normalised form, id type, check level (checksum only where the authority publishes the algorithm)…

• get_changes

  FREE unmetered change + freshness feed. After any paid series or answer call, call this before you assume the cached value is still the law. Returns every series whose current value took effect on or after `since` (default last 30 days)…

• get_calendar

  FREE, unmetered. GET /v1/calendar for this brand's continent. Optional country (ISO 3166-1 alpha-2) and series. Derives reverify_by from last_confirmed + update_cycle_days (the same window that sets stale) and, only when…

• register_alert

  Bind a webhook so the next gazette does not silently stale a value you already paid for. REGISTERING IS FREE. Register: $0 · Delivery after trial: $0.05. First 3 deliveries are free; later deliveries are $0.05 and refunded if the webhook…