---
title: "Validate fNAV profile against grid connection capacity (Phase 5)"
method: POST
path: "/api/grid-connection/fnav/validate"
tags: ["Netzfahrplan / fNAV"]
---

# Validate fNAV profile against grid connection capacity (Phase 5)

`POST /api/grid-connection/fnav/validate`

## Request

- Base URL: `https://api.cernion.de`
- URL: `https://api.cernion.de/api/grid-connection/fnav/validate`
- Auth: none declared

Applies the fNAV capacity model (§14a EnWG) for a proposed grid connection. Runs N-1 compliance check with hybrid threshold (Option C: domain default + tenant/project/scenario override). Reports technical feasibility and enforces governance gate (Option B: final status is requires_governance_decision until legalStatus=approved AND contractStatus=signed). Delegates to grid-operations.netzfahrplanGenerate for the deterministic core.

## Query parameters

- `token` string

## Request body

- object
  - `gridOperatorName` string
  - `voltageLevel` 'NS' | 'MS' | 'HS': Voltage level of the connection point
  - `fnavProfile` object, required
    - `requestedCapacity` number, required: Requested capacity in kW
    - `firmCapacity` number: Guaranteed firm capacity in kW
    - `flexibleCapacity` number: Curtailable §14a flex capacity in kW
    - `curtailmentWindow` number: Max curtailment hours per day (0–24)
    - `operatingConstraint` string
    - `signalPriorityPolicy` string
    - `controlEvidenceRef` string
    - `contractStatus` string
    - `legalStatus` string
  - `n1ThresholdOverride` object: Override N-1 threshold (MVA) at tenant/project/scenario level
    - `tenant` number
    - `project` number
    - `scenario` number
  - `ownerContact` string: Responsible owner — required for governance approval
  - `token` string: Optional Cernion MCP token for this request. Overrides CERNION_TOKEN when provided.

## Response `200`

fNAV validation result with capacity model, N-1 check, and governance status

- object
  - `capacityModel` object: Normalised fNAV capacity model
  - `n1Check` object: N-1 compliance result
  - `feasibility` 'feasible' | 'conditional' | 'copper_needed'
  - `governanceStatus` string
  - `governanceBlockers` string[]
  - `contractGate` object: Explicit contract-gate assessment
  - `governanceArtifact` object, nullable
  - `decisionChain` object[]
  - `proof` object
  - `findings` object[]
  - `metadata` object
  - `source` string

---

[API](https://skmtc.dev/cernion/apis/cernion-energy-tools-api.md) · [All operations](https://skmtc.dev/cernion/apis/cernion-energy-tools-api/llms.txt) · [OpenAPI document](https://skmtc.dev/cernion/apis/cernion-energy-tools-api/revisions/cdb94473b538?raw)