MCP Server & API Pricing

An anonymous free tier for open experimentation, a free key you can create yourself in one click at double the anonymous allowance, plus a published rate card for production workloads: Developer at $19/month, Business at $99/month, and Enterprise on custom terms. Paid plans are card subscriptions: you check out, and your key is shown to you on the confirmation page.

This page is the API, not the Widgets

These tiers cover our API — the hosted MCP server and its REST companion, for developers and advisors integrating our calculations into their own products. Our separate Widgets product (embeddable calculators you add to your own site with one script tag) has its own plans — see Widget pricing.

One endpoint, five tiers

Every tier hits the same endpoint (https://mcp.digitalcalculator.info/mcp) and shares the same 9 free tools — the 8 calculator tools plus money_flow_map — with identical calculation math. The anonymous-parity invariant (per our versioning contract) guarantees that anonymous and authenticated responses are byte-identical for the same inputs — what you pay for is allowance, identity, and support, never different math.

Read this before you compare us to anyone else

Every tier on this page — anonymous and paid alike — is served through one API Gateway endpoint under a single global throttle of 100 requests/minute (burst 50), shared across all callers. No tier reserves throughput. A tier is a ceiling on how much you may consume, not a promise of how fast you will be served.

That is why allowances below are published as calls per UTC day and not as a guaranteed per-minute rate. A daily cap is a number we can hold ourselves to. A per-minute guarantee on a shared pool would be a number we could not, and we would rather publish a smaller true figure than a larger convenient one. If your workload needs reserved capacity, that is an Enterprise conversation, and we will tell you honestly what it would cost to provision.

Anonymous tier — Free

The default tier. No signup, no API key, no email address. Just POST to the endpoint and it works.

9 MCP tools — composite tools covering mortgage, loan, and paycheck math; retirement planning (401(k), Social Security, RMD, IRA, and Roth conversion); contribution-limit eligibility; growth projection; emergency funds; and the money_flow_map interactive money-flow map
Penny-exact math — every response is byte-parity with the corresponding calculator on digitalcalculator.info (parity-tested via Vitest)
Full response envelope — YMYL disclaimer, methodology URL + version, engine version, calculation timestamp on every call
Allowance — 500 calls per UTC day per IP address, with a short-term ceiling of 30 calls per 5-minute window per IP. Exceeding either returns HTTP 429 with Retry-After and X-RateLimit-* headers
Shared throttle — on top of the per-IP allowance, all traffic shares the 100 requests/min global gateway throttle described above, so heavy sustained load from one caller can still slow things down for everyone
Support — the FAQ, the API Reference, and the general admin@markcolabs.com inbox (best-effort, community-style response)
Terms — governed by the hosted-API terms in LICENSE-API.md (acceptable use, no warranty)

The anonymous tier is the right choice for exploration, prototypes, individual developers, hobby agents, and any workload where "healthy for everyone" throttling is acceptable.

Free key — no card, no email

When the anonymous per-IP allowance stops being enough, create a key for yourself right here. There is no sign-up form, no credit card, and nothing to wait for — the key is generated the moment you ask for it and works on your very next request.

Allowance — 1,000 calls per UTC day counted against your key alone, with a short-term ceiling of 60 calls per 5-minute window. That is double the anonymous daily allowance, and it is yours rather than shared with everyone else behind your IP address
Same 9 tools, same math — the anonymous-parity invariant applies here too; a key buys allowance and identity, never different numbers
Usable immediately — send it as Authorization: Bearer <your key> on the same endpoints you are already calling
Valid for one year from creation, and revocable by us if abused
Stored as a SHA-256 hash only — we never hold the key itself, which is exactly why we cannot re-send it to you later

Create a free key

Your key is displayed once, on this page, and is never shown again. It is not emailed to you — we do not ask for your email address and have no way to send it. Copy it somewhere safe before you leave this page. If you lose it, create another one.

Ready for more than 1,000 calls a day, or need a named account with a support channel? That is the Developer tier below.

The rate card

Paid tiers are for production integrations where the anonymous tier is the wrong shape — a fintech app with steady daily volume, a research team running batched simulations, or a B2B integration where per-key metering, attribution and a support channel matter more than "no signup." A paid key is metered by an application-layer per-key token bucket, live in production today: your daily allowance is counted against your key alone and is not consumed by anonymous traffic. It is a private budget, not private bandwidth — the gateway throttle above is still shared.

Published rate card for the Digital Calculator MCP server API
Tier	Price	Daily cap (per UTC day)	Short-term ceiling
Anonymous	Free — no signup	500 calls per IP	30 calls / 5-minute window, per IP
Free key	Free — self-serve	1,000 calls per key	60 calls / 5-minute window, per key
Developer	$19/mo	10,000 calls per key	300 calls / 5-minute window, per key
Business	$99/mo	50,000 calls per key	500 calls / 5-minute window, per key
Enterprise	Custom	Negotiated per agreement	Negotiated per agreement

Both columns are ceilings, not reservations. The short-term ceiling exists so one key cannot monopolize the shared pool in a burst; it is not additional guaranteed bandwidth. Developer and Business are monthly card subscriptions: you check out, your key is created automatically and shown to you on the confirmation page, and it works on your very next request. Cancelling stops the renewal — your key keeps working until the end of the period you have already paid for, not from the moment you click cancel.

Card checkout is not switched on yet — email us and we will set you up today

The subscription plumbing is built and tested, but we are still finalising the merchant account behind it, so there is no live checkout link on this page right now. In the meantime, email admin@markcolabs.com with the tier you want and we will provision your key by hand at the same published price. Nothing about the tier, the allowance, or the key itself differs — only how the first payment is collected. The anonymous tier and the free key are unaffected and available right now.

Developer — $19/month

For a single production integration that needs a dependable, attributable daily allowance.

Your own Bearer key — created the moment your subscription starts and shown to you on the confirmation page. We store only a SHA-256 hash of it, so it stays retrievable at that page for 24 hours and cannot be recovered afterwards (we will issue a replacement if you lose it)
Your own daily budget — 10,000 calls per UTC day counted against your key alone, with a 300-call / 5-minute short-term ceiling, enforced per key at the application layer
Usage attribution — per-key call counts for billing reconciliation and compliance audits
Direct support — email channel with the maintainer, ahead of the general inbox
Contract coverage — published SemVer policy, deprecation windows, and the anonymous-parity invariant per the versioning contract

Start a Developer subscription — see the note above on how the first payment is collected today.

Business — $99/month

Everything in Developer, at five times the daily allowance, plus white-label report output.

Highest published allowance — 50,000 calls per UTC day per key, with a 500-call / 5-minute short-term ceiling
Branded PDF reports — the generate_report tool renders client-ready PDF reports carrying your logo and brand colors instead of ours. The branding pipeline is built and rolling out now — we will confirm availability for your account when you request a key
Priority triage — issues that affect your integration go to the front of the queue

Start a Business subscription — see the note above on how the first payment is collected today.

Enterprise — Custom

For integrations that outgrow the published tiers or need bespoke terms.

Negotiated allowances — daily caps and short-term ceilings sized to your workload, beyond the published numbers
Reserved capacity, if you need it — the only route to throughput that is genuinely provisioned for you rather than drawn from the shared pool. It requires us to buy that capacity, so we will price it openly rather than promise it for free
Multiple keys — separate staging and production keys you can monitor and revoke independently
Custom terms — procurement paperwork, security questionnaires, and agreement language handled together

Talk to us about Enterprise

Feature comparison

Feature comparison across the Anonymous, Free key, Developer, Business, and Enterprise tiers of the Digital Calculator MCP server
Feature	Anonymous (Free)	Free key (Free)	Developer ($19/mo)	Business ($99/mo)	Enterprise (Custom)
All 8 calculator tools plus `money_flow_map`	Yes	Yes	Yes	Yes	Yes
Byte-parity math (penny-exact vs. site)	Yes	Yes (invariant — never differs)	Yes (invariant — never differs)	Yes (invariant — never differs)	Yes (invariant — never differs)
Daily cap (per UTC day)	500 calls per IP	1,000 calls per key	10,000 calls per key	50,000 calls per key	Negotiated
Short-term ceiling	30 calls / 5 min, per IP	60 calls / 5 min, per key	300 calls / 5 min, per key	500 calls / 5 min, per key	Negotiated
Reserved throughput	No — shared 100 req/min gateway throttle	No — shared 100 req/min gateway throttle	No — shared 100 req/min gateway throttle	No — shared 100 req/min gateway throttle	Available, priced per agreement
Per-caller identity + usage attribution	No	Per-key call counts, but the key is anonymous to us	Yes (per-key call counts)	Yes (per-key call counts)	Yes (per-key call counts)
Branded PDF reports (your logo + colors)	No	No	No	Yes (rolling out)	Yes (rolling out)
Support channel	Best-effort general inbox	Best-effort general inbox	Direct maintainer email	Direct maintainer email, priority triage	Priority triage + scoping conversations
Terms governing the endpoint	`LICENSE-API.md`	`LICENSE-API.md`	`LICENSE-API.md` + subscription terms	`LICENSE-API.md` + subscription terms	Custom agreement
Onboarding	None — just call the endpoint	Self-serve — one click on this page, no email, works immediately	Subscribe → key created automatically → shown on the confirmation page (see onboarding)	Subscribe → key created automatically → shown on the confirmation page (see onboarding)	Email → scoping conversation → issued key(s)

What paid tiers do NOT include (yet)

We are honest about the committed benefits above. Formal SLAs, an uptime dashboard, and a self-serve key-rotation UI are on the roadmap but not shipped — if any of those matter for your integration, tell us when you subscribe so we can weigh them against other work.

There is also no account and no login, on any tier. Your key is the identity. That means there is no key list to browse and no password to reset — but it also means a lost key can only be replaced, not re-sent, because we hold nothing but its hash. Paid keys stay retrievable at the confirmation page for 24 hours after checkout; after that, email us and we will revoke the old key and issue a new one.

The free key is narrower still: it is not tied to any address at all, so there is no window and no recovery. Treat the key you copy as the only copy.

The contract

All tiers are covered by the same versioning contract published at /mcp/contract/. That page defines the SemVer policy (what a major, minor, or patch bump means for the tool surface), the deprecation window for anything we change, and the anonymous-parity invariant — the promise that authenticated and anonymous callers receive byte-identical responses to the same inputs. Read that page before integrating so you know exactly what the change surface looks like.

Getting a key

For a free key you do not need us at all — create one yourself in a click, no email address required.

For Developer and Business, the flow is a card subscription: you check out, your key is created automatically the moment the subscription starts, and it is shown to you on the confirmation page — where it stays retrievable for 24 hours in case you close the tab. There is no form to fill in, no approval step, and no waiting. (See the note above for how the first payment is collected while we finalise the merchant account.) The full flow is documented at onboarding.

For Enterprise, start with an email — the allowances, key topology and terms are negotiated, so it begins with a short scoping conversation rather than a checkout. Email admin@markcolabs.com with:

What you're building (one paragraph)
Which tools you'd be calling and roughly how often
Any timing constraint (production launch date, procurement window, etc.)

If the anonymous tier is genuinely sufficient for your use case, we will tell you that too. General questions that aren't key-related go to admin@markcolabs.com.

References

MCP Server overview — what the server is + how to connect
Quickstart — first call in under 5 minutes (anonymous tier)
API Reference — all 9 tools with input schemas and output shapes
Versioning contract — SemVer policy, deprecation window, anonymous-parity invariant
API key onboarding — the full flow from checkout to first authenticated call
Your API key — where a paid key is shown after checkout, and for how long it stays retrievable
FAQ — accuracy, YMYL posture, support