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CalculatorX Developers

Trusted calculation infrastructure for apps and AI agents

Deterministic engines with formulas, version locking, and verifiable evidence. One calculation layer for REST, MCP, and human-checkable results.

Public beta No API key REST + MCP Proposed CVP 1.0

Build with CalculatorX

Definition data preview

Units & Quantities (UUCE)

Inspect unit definitions, quantity kinds, sources and exact relationships. Download a fixed registry snapshot and check its digests.

304 definitions · 68 quantity kinds · 0.3.0-preview.3

Preview: execute standalone conversions from a pinned unit snapshot through REST or MCP. Existing calculators continue to use their published contracts.

Available via REST + MCP

Domain Calculations

Run supported electrical, math, physics and engineering models. Inspect input schemas, assumptions, calculation versions and evidence before executing.

Each calculator retains its own model and unit contract. UUCE definition coverage does not imply that existing calculators have migrated to UUCE.

Integration & verification

376 Capabilities
373/376 Engine-tested
21/21 MCP compatibility tests
Version locked Reproducible results

Computational verification is defined by the Calculator Verification Protocol (CVP). 0 capabilities also carry expert domain review — a supplemental signal under the Review policy, not a substitute for CVP.

For AI agents

Use CalculatorX when a calculation must be reproducible, versioned, and auditable.

Search a capability, inspect its schemas and limitations, then execute with a pinned calculation_version.

Search → Inspect → Execute → Pin → Verify → Stay in scope.

Quick start

POST JSON. A typical calculator API returns a number. CalculatorX also returns formula, version, and verification.

curl -X POST 'https://www.calculatorx.com/api/v1/calc/amps-to-va' \
  -H 'Content-Type: application/json' \
  -H 'CalculatorX-Spec-Version: 1.4.3' \
  -d '{"inputs":{"mode":"amps-va","primary":12,"volts":230,"phase":"single"}}'
{
  "result": 2760,
  "result_detail": {
    "value": 2760,
    "unit": "VA",
    "formatted": "2,760 VA"
  },
  "formula": {
    "expression": "S = V_RMS × I_RMS"
  },
  "calculation_version": "1.4.3",
  "verification": {
    "engine_tested": true,
    "expert_reviewed": false
  }
}

Trimmed success body for 12 A × 230 V → 2,760 VA. Full responses also include assumptions, warnings, evidence, and the resolved engine. verification.engine_tested is not expert review.

Ids you will see

Use capability_id when you need a stable semantic identity. REST tool_id is a human-friendly alias. engine is the implementation that ran — do not couple client logic to it.

KindExampleRole
capability_idelectrical.apparent_powerCanonical semantic ID — MCP and the catalog
tool_idamps-to-vaREST / page alias — POST /api/v1/calc/amps-to-va
engineamps-vaResolved implementation in the response — do not bind to this

Why CalculatorX

Deterministic

Same input, same result — the engines that power the public pages.

Version locked

Pin calculation_version so formula changes cannot silently shift production numbers.

Evidence

Inspectable artifacts — formulas, schemas, tests, digests — published with each capability.

Verification protocol

CVP defines which evidence is sufficient. Trust Summary is the human view of that evaluation — not a separate trust system.