CVP verified calculation capability

Low-pass filter Calculation Capability

Solve first-order RC LPF cutoff fc = 1/(2πRC) from any two of R, C, fc; optional magnitude |H(f)| in linear and dB.

Electrical Capability ID electrical.lpf version 1.0.0 CVP VERIFIED CURRENT Engineering

Model

Cutoff

Cutoff: fc = 1 / (2πRC)
Magnitude: |H| = 1 / √(1+(f/fc)²)

Inputs / Outputs

Canonical symbols for this capability. Agent schemas remain the contract.

Symbol	Quantity	Unit	Role
`R`	Resistance	—	input / output
`C`	Capacitance	—	input / output
`fc`	Cutoff frequency	—	input / output
`f`	Optional evaluation frequency	—	input / output
`tau`	—	—	output
`omega_c`	—	—	output
`H_lin`	—	—	output
`H_dB`	—	—	output

Assumptions / Validity

Declared scope for this capability. Do not use it outside this domain.

Assumptions

Ideal lumped series-R / shunt-C LPF.
When R and C are both given, fc is recomputed from them.

Example

One numerical check. The calculator page holds worked steps and FAQ.

R=10 kΩ, C=1 µF → fc≈15.915 Hz; at fc, H_dB≈−3.01 dB

Open this example in the calculator

Trust

CVP VERIFIED · CVP protocol 1.0.0-proposed · Engineering assurance. Computational verification is defined by CVP. Supplemental domain review (internal) and named expert review are defined by the Review policy and do not by themselves determine CVP conformance.

CVP: CVP VERIFIED · CVP protocol 1.0.0-proposed · Engineering assurance· View Manifest · CVP overview · Specification
Assurance: Engineering
Declared partition coverage: PASS · 4/4 declared partitions (solve-rc, with-f, solve-C, invalid-domain)
Calculation version: 1.0.0
Verification: 10/10 calculation tests · 3/3 legacy golden · 3/3 legacy boundary · 4/4 legacy property
Production surface contract: 5/5
Versions: Calculation 1.0.0 · CVP protocol 1.0.0-proposed
CVP identity: 4/4 property · digest 00b0f7286660
Reference: O1 model · O2 expected_values · O2 numerical_behavior
Interfaces: PASS · UI (SSR) / REST / MCP
ui-ssr is query-result HTML, not a live browser session.
CVP suite: 3/3 golden · 3/3 CVP boundary · 3/3 invalid · 4/4 property · 1/1 cross-interface · 3/3 CVP contract
Supplemental domain review: Internal · Pass · electrical-engineer
Named expert review: Not performed
Version lock: Supported (409 VERSION_MISMATCH)
Artifact consistency: Build verified · 1.0.0 (workspace artifacts agree)
Review-policy tier: Internal engineering review — catalog token expert_verified; supplemental; not CVP status

This calculator CURRENT · Public schema 1.0.0 matches · Semantic contract ✓ · Production attested · Public/cache ✓ · Origin ✓

Call this capability

Human page, REST, and MCP share the same engine and calculation_version. Build verified hashes workspace artifacts only. After deploy, attest:production GETs canonical URLs twice — the public/cached view an Agent actually hits, and origin — including every /capabilities/{id} HTML page. Public Capability HTML version must match catalog before production attestation passes. Live Trust rows above fetch /.well-known/calculatorx-production-attestation.json and the output schema const. Build hashes: release integrity. That proves currently published page / engine / schema / evidence / MCP agree — not that a historical version is independently immutable. Reference Calculation Standard — Production surface contract 5/5.

curl -sS -X POST 'https://www.calculatorx.com/api/v1/calc/lpf' \
  -H 'Content-Type: application/json' \
  -d '{"inputs":{"R":10000,"C":0.000001},"calculation_version":"1.0.0"}'

{
  "inputs": {
    "R": 10000,
    "C": 0.000001
  },
  "calculation_version": "1.0.0"
}

POST /api/v1/calc/lpf. This is a POST calculate endpoint — do not GET it.

Full REST contract: REST API docs.

Tool id: lpf
Engine: lpf
REST: POST /api/v1/calc/lpf
MCP: execute_calculation with capability_id: "electrical.lpf"
Agent input schema: Canonical (MCP / Agent)
Output schema: JSON Schema (latest)
Versioned input schema: Immutable pin (1.0.0)
Versioned output schema: Immutable pin (1.0.0)

References

Human-readable sources plus CVP reference evidence classes.

Sources

Horowitz & Hill — The Art of Electronics — Single-pole RC filters
IEC 60050 — IEV — Cut-off frequency

Reference evidence classes: O1 model · O2 expected_values · O2 numerical_behavior

Try with an agent

Inspect, then execute. Same engine as REST and the human calculator.

curl -sS -X POST 'https://www.calculatorx.com/mcp' \
  -H 'Content-Type: application/json' \
  -H 'MCP-Protocol-Version: 2026-07-28' \
  -H 'Mcp-Method: tools/call' \
  -H 'Mcp-Name: inspect_capability' \
  -d '{"jsonrpc":"2.0","id":1,"method":"tools/call","params":{"name":"inspect_capability","arguments":{"capability_id":"electrical.lpf"},"_meta":{"io.modelcontextprotocol/protocolVersion":"2026-07-28","io.modelcontextprotocol/clientInfo":{"name":"calculatorx-docs-example","version":"1.0.0"},"io.modelcontextprotocol/clientCapabilities":{}}}}'

curl -sS -X POST 'https://www.calculatorx.com/mcp' \
  -H 'Content-Type: application/json' \
  -H 'MCP-Protocol-Version: 2026-07-28' \
  -H 'Mcp-Method: tools/call' \
  -H 'Mcp-Name: execute_calculation' \
  -d '{"jsonrpc":"2.0","id":2,"method":"tools/call","params":{"name":"execute_calculation","arguments":{"capability_id":"electrical.lpf","inputs":{"R":10000,"C":0.000001},"calculation_version":"1.0.0"},"_meta":{"io.modelcontextprotocol/protocolVersion":"2026-07-28","io.modelcontextprotocol/clientInfo":{"name":"calculatorx-docs-example","version":"1.0.0"},"io.modelcontextprotocol/clientCapabilities":{}}}}'

Pin calculation_version (1.0.0) when the result must stay reproducible.

Inspect the trust tier and required assurance level before execution. Full protocol notes: MCP docs.