---
title: "Aggregate traffic-crash context by radius, severity, and mode"
method: POST
path: "/api/locus-traffic-crash-context"
tags: ["traffic", "crashes", "transportation", "aggregate", "safety", "read-only", "paid", "x402", "category:safety"]
---

# Aggregate traffic-crash context by radius, severity, and mode

`POST /api/locus-traffic-crash-context`

## Request

- Base URL: `https://api.locus.report`
- URL: `https://api.locus.report/api/locus-traffic-crash-context`
- Auth: one of:
  - API key in header `PAYMENT-SIGNATURE`
  - API key in header `Authorization`

Returns small-cell-suppressed crash-count aggregates near an address, with explicit severity classes, for agents checking crash context. Returns the same records as locus_traffic_crash_context. Use this when your client can only call paid x402 routes. Use locus_traffic_crash_context instead when you can call Locus free tools (REST tools/call or MCP).

## Request body

- object
  - `address` string: US street address. Localized coverage is derived from the crash-source registry: Chicago all-reported; Virginia reportable-threshold; North Carolina partial subsets (K+A and nonmotorist); Pikes Peak region reportable-threshold; nationwide FARS fatal-only companion. Provide this or latitude+longitude.
  - `latitude` number: Decimal latitude; provide with longitude. The response never returns the exact query point.
  - `longitude` number: Decimal longitude; provide with latitude. The response never returns the exact query point.
  - `radiiMeters` integer[], required: One to three bounded radii in meters; each must be 200-1,000. Defaults to 200, 500, and 1,000.
  - `lookbackYears` integer, required: Recent calendar lookback in years; defaults to 3 and is capped at 10. A source's actual available years still control.

## Response `200`

Atomic read result. A substantive result is paid; an empty/out-of-coverage result carries charged:false (x402 settlement suppressed).

- object

## Other responses

- `400`: Invalid request body.
- `402`: Payment Required. For x402 v2, repeat the identical request with a valid PAYMENT-SIGNATURE header (legacy X-PAYMENT is accepted for compatibility), or use Authorization: Payment for MPP Tempo when advertised in x-payment-info.offers.

---

[API](https://skmtc.dev/locus/apis/locus-api.md) · [All operations](https://skmtc.dev/locus/apis/locus-api/llms.txt) · [OpenAPI document](https://skmtc.dev/locus/apis/locus-api/revisions/ba7786b74adb?raw)