MCP Server & API Pricing
A permanent anonymous free tier for open experimentation, plus a published rate card for production workloads: Developer at $49/month, Business at $99/month, and Enterprise on custom terms. The free tier will always be free. Paid keys are requested by email and typically provisioned within one business day.
One endpoint, four tiers
Every tier hits the same endpoint (https://mcp.digitalcalculator.info/mcp) and shares the same 14 free tools — the 13 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 capacity, identity, and support, never different math.
Anonymous tier — Always Free
The default tier. No signup, no API key, no email address. Just POST to the endpoint and it works.
- 14 MCP tools — mortgage, loan, compound interest, savings, inflation, 401(k), Social Security, paycheck, IRA, Roth conversion, RMD, HSA, emergency fund, plus the
money_flow_mapinteractive 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
- Rate limit — API Gateway global throttle of 100 requests/min across all anonymous callers (burst 50). This is a shared bucket; heavy sustained load from one caller can degrade the experience for others
- 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. It is not going away.
The rate card
Paid tiers are for production integrations where the anonymous tier's shared throttle 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 and a support channel matter more than "no signup." Rate limits on paid keys are enforced by a dedicated per-key token bucket, live in production today — your capacity is yours, independent of the anonymous pool and of every other key.
| Tier | Price | Rate limit | Daily quota |
|---|---|---|---|
| Anonymous | Free — always | Shared global throttle (100 req/min, burst 50) | — |
| Developer | $49/mo | 1,000 requests per 5-minute window, dedicated per key | 10,000 requests |
| Business | $99/mo | 10,000 requests per 5-minute window, dedicated per key | 100,000 requests |
| Enterprise | Custom | Negotiated per agreement | Negotiated per agreement |
Billing is a simple monthly invoice — there is no credit-card form or self-serve billing portal yet (see what paid tiers do not include). Email us to start, change, or stop a subscription.
Developer — $49/month
For a single production integration that needs dependable, dedicated capacity.
- Your own Bearer key — sent over a secure channel, stored server-side only as a SHA-256 hash
- Dedicated rate limit — 1,000 requests per 5-minute window and 10,000 requests/day, 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
Business — $99/month
Everything in Developer, at ten times the capacity, plus white-label report output.
- Highest published limits — 10,000 requests per 5-minute window and 100,000 requests/day, dedicated per key
- Branded PDF reports — the
generate_reporttool 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
Enterprise — Custom
For integrations that outgrow the published tiers or need bespoke terms.
- Negotiated limits — rate windows and daily quotas sized to your workload, beyond the published ceilings
- Multiple keys — separate staging and production keys you can monitor and revoke independently
- Custom terms — procurement paperwork, security questionnaires, and agreement language handled together
Feature comparison
| Feature | Anonymous (Free) | Developer ($49/mo) | Business ($99/mo) | Enterprise (Custom) |
|---|---|---|---|---|
All 13 calculator tools plus money_flow_map |
Yes | Yes | Yes | Yes |
| Byte-parity math (penny-exact vs. site) | Yes | Yes (invariant — never differs) | Yes (invariant — never differs) | Yes (invariant — never differs) |
| Rate limit shape | Shared global throttle (100 req/min, burst 50) | Dedicated per-key: 1,000 req / 5 min | Dedicated per-key: 10,000 req / 5 min | Negotiated |
| Daily quota | — (shared throttle only) | 10,000 requests | 100,000 requests | Negotiated |
| Per-caller identity + usage attribution | No | Yes (per-key call counts) | Yes (per-key call counts) | Yes (per-key call counts) |
| Branded PDF reports (your logo + colors) | No | No | Yes (rolling out) | Yes (rolling out) |
| Support channel | 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 + subscription terms |
LICENSE-API.md + subscription terms |
Custom agreement |
| Onboarding | None — just call the endpoint | Email key request — typically 1 business day (see onboarding) | Email key request — typically 1 business day (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, self-serve signup and billing, 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 request a key so we can weigh them against other work.
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.
Request a key
Ready to start? Email admin@markcolabs.com with the subject "API Key Request" and:
- The tier you want — Developer, Business, or Enterprise
- 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.)
For Developer and Business, we typically provision the key within one business day and deliver it over a secure channel — the full flow is documented at onboarding. For Enterprise, we start with a short scoping conversation. If the anonymous tier is genuinely sufficient for your use case, we will tell you that too.
General questions that aren't key-related still 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 14 tools with input schemas and output shapes
- Versioning contract — SemVer policy, deprecation window, anonymous-parity invariant
- API key onboarding — how a key is requested, provisioned, and delivered
- FAQ — accuracy, YMYL posture, support