---
title: "Regulatory Report Period-over-Period Variance Explainer"
method: POST
path: "/v1/tools/explain_regrpt_variance"
tags: ["TODO_TAGS_REVIEW", "TODO_AP2_EXPORT_REVIEW"]
---

# Regulatory Report Period-over-Period Variance Explainer

`POST /v1/tools/explain_regrpt_variance`

## Request

- Base URL: `https://ainumbers.co`
- URL: `https://ainumbers.co/v1/tools/explain_regrpt_variance`
- Auth: none declared

Computes period-over-period variance across a regulatory report instance pair -- absolute and relative movement per line item against a policy-supplied materiality threshold (default plus per-line overrides), ranked by contribution (largest absolute movement first) -- and flags which movements require a written explanation, i.e. exceed materiality with no matching explanation on file. Does not judge whether a supplied explanation is adequate; that is a human review-and-approval step downstream (RGEC-K-2's gate: an unexplained material variance routes to review_required). Pairs with art-484-regrpt-editcheck-runner's rule-based edit checks -- this node handles analytical-review variance, not rule pass/fail.

**Tool URL:** https://ainumbers.co/chaingraph/art-485-regrpt-variance-explainer.html

## Request body

- object
  - `explanations` unknown, required
  - `instance_pair` unknown, required
  - `materiality_policy` unknown, required

## Response `200`

Successful tool execution result

- object
  - `compliance_flags` unknown[]
    - unknown
  - `current_as_of` string
  - `note` string
  - `policy_version` string
  - `prior_as_of` string
  - `summary` object
    - `all_material_explained` boolean
    - `material_count` integer
    - `requires_explanation_count` integer
    - `total_abs_movement` integer
    - `total_line_items` integer
  - `variances` object[]
    - `abs_change` integer
    - `contribution` integer
    - `current_value` integer
    - `has_explanation` boolean
    - `is_material` boolean
    - `line_item` string
    - `pct_change` number
    - `prior_value` integer
    - `rank` integer
    - `requires_explanation` boolean
    - `threshold_abs` integer
    - `threshold_pct` number

---

[API](https://skmtc.dev/ainumbers/apis/ainumbers-co-fintech-intelligence-suite.md) · [All operations](https://skmtc.dev/ainumbers/apis/ainumbers-co-fintech-intelligence-suite/llms.txt) · [OpenAPI document](https://skmtc.dev/ainumbers/apis/ainumbers-co-fintech-intelligence-suite/revisions/b462e4f5bb28?raw)