CVP verified calculation capability
Size PCB copper traces or check ampacity with the IPC-2221 I = k·ΔT^0.44·A^0.725 relation for external and internal layers; optional u_* compose expanded uncertainty on width or I via Uncertainty Engine.
Electrical · Pcb Capability ID electrical.pcb.trace_width version 1.1.1 CVP VERIFIED CURRENT Engineering
Current vs area
I = k × ΔT^0.44 × A^0.725w = A / t (t ≈ 1.378 mil × oz)Modes: width · current
Canonical symbols for this capability. Agent schemas remain the contract.
| Symbol | Quantity | Unit | Role |
|---|---|---|---|
I | Trace current | — | input / output |
width_mil | Trace width | — | input / output |
dT | Temperature rise | — | input / output |
copper_oz | Copper weight | — | input / output |
layer | k=0 | — | input / output |
u_I | Optional standard uncertainty of I | — | input |
u_width_mil | Optional standard uncertainty of width_mil | — | input |
u_dT | Optional standard uncertainty of dT | — | input |
u_copper_oz | Optional standard uncertainty of copper_oz | — | input |
uncertainty_k | Coverage factor for expanded U on primary result; default 2 when any u_* is set | — | input |
confidence | Optional coverage probability instead of uncertainty_k | — | input |
width | — | mm | output |
area_mil2 | — | — | output |
thickness_mil | — | — | output |
k | — | — | output |
uncertainty | Present when any u_* is provided; composed via engineering | — | output |
Declared scope for this capability. Do not use it outside this domain.
Assumptions
One numerical check. The calculator page holds worked steps and FAQ.
I=10 A, ΔT=10 °C, 1 oz external → width ≈ 283.2 mil
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.
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 8/8.
curl -sS -X POST 'https://www.calculatorx.com/api/v1/calc/pcb-trace-width' \
-H 'Content-Type: application/json' \
-d '{"inputs":{"mode":"width","I":10,"dT":10,"copper_oz":1,"layer":"external"},"calculation_version":"1.1.1"}'{
"inputs": {
"mode": "width",
"I": 10,
"dT": 10,
"copper_oz": 1,
"layer": "external"
},
"calculation_version": "1.1.1"
}POST /api/v1/calc/pcb-trace-width. This is a POST calculate endpoint — do not GET it.
Full REST contract: REST API docs.
Declared calculation modes for this capability.
widthcurrentHuman-readable sources plus CVP reference evidence classes.
Sources
Reference evidence classes: O1 model · O2 expected_values · O2 numerical_behavior
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.pcb.trace_width"},"_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.pcb.trace_width","inputs":{"mode":"width","I":10,"dT":10,"copper_oz":1,"layer":"external"},"calculation_version":"1.1.1"},"_meta":{"io.modelcontextprotocol/protocolVersion":"2026-07-28","io.modelcontextprotocol/clientInfo":{"name":"calculatorx-docs-example","version":"1.0.0"},"io.modelcontextprotocol/clientCapabilities":{}}}}'Pin calculation_version (1.1.1) when the result must stay reproducible.
Inspect the trust tier and required assurance level before execution. Full protocol notes: MCP docs.