Alleghany Corporation
Alleghany Corporation is a holding company engaged in property and casualty reinsurance and insurance through its subsidiaries, with additional investments in non-financial businesses held via Alleghany Capital. Founded in 1929 by railroad entrepreneurs Oris and Mantis Van Sweringen, the company transitioned over decades from rail holdings into specialty insurance and reinsurance, and is headquartered at One Rockefeller Plaza in New York City. Its principal insurance subsidiaries are Transatlantic Reinsurance Company (TransRe), a global reinsurer founded in 1977 with roughly 600 employees across 23 offices and more than $40 billion in claims paid to date; RSUI Group, a wholesale excess and surplus (E&S) underwriter spanning Property, Casualty, Professional Liability, Management Liability, and Binding Authority lines; and CapSpecialty, a specialty casualty and surety underwriter. Alleghany Capital holds non-insurance operating companies including toy and collectibles maker Jazwares (Squishmallows, Pokémon, Roblox, Fortnite licensed lines). On March 21, 2022, Berkshire Hathaway announced an $11.6 billion all-cash acquisition of Alleghany at $848.02 per share, which closed in October 2022. Alleghany now operates as a wholly-owned subsidiary of Berkshire Hathaway, contributing approximately $8.8 billion in 2025 gross premiums written and roughly $14 billion in insurance float to the parent. As a holding company whose operating units distribute exclusively through reinsurance intermediaries, wholesale brokers, and independent agents, Alleghany and its subsidiaries do not publish a developer portal, OpenAPI specifications, SDKs, or any other machine-readable API artifacts; the only digital surfaces exposed publicly are gated broker and agent login portals.
Index entry only — little beyond a description and a link, and nothing machine-readable enough for an agent to act on without a human reading the site first.
API Evangelist profiles Alleghany Corporation the way a machine reads it — 1 machine-readable artifact, pulled from the provider's own public surface and indexed so a developer, an analyst, or an AI agent can evaluate it against every other provider on the network.
Every provider in the network is reduced to the same set of machine-readable artifacts — OpenAPI contracts, event specifications, GraphQL schemas, runnable collections, pricing and rate-limit signals, security posture, OAuth scopes, and the agent surfaces (MCP servers and skills) that let software drive the API on its own. We profile them because the interface is the part of a company you can actually inspect: it is a truer signal of what a provider does than any marketing page. From those artifacts we compute the Kin Score — Alleghany Corporation scores 3.0/100 (minimal), with a separate agent-readiness read of 0/100 (human only). The full breakdown is below, followed by every artifact we hold — each card links through to its machine-readable definition on apis.io.
Kin Score
This is the API Evangelist rating — a single, repeatable read computed from the artifacts on this page. Green fill is points earned; the red track is points possible, so every bar shows earned-versus-possible at a glance. Every facet and dimension name is a link: it opens that measurement's page on APIs.io, where the rating runs across the whole catalog — the exact checks that feed it, how every profiled provider distributes on it, and who is at the top of it.
Kin Score
How this is scored →scored 2026-09-10 · rubric v0.20.0
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<!-- Kin Score · API Evangelist -->
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title="Alleghany Corporation on API Evangelist — API profile and Kin Score">
<img src="https://apis.io/badge/alleghany.svg"
alt="Alleghany Corporation Kin Score — API readiness rating by API Evangelist" width="150" height="150" loading="lazy">
</a>[](https://providers.apievangelist.com/providers/alleghany/)<!-- Kin Score · API Evangelist -->
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title="Alleghany Corporation on API Evangelist — API profile and Kin Score">
<img src="https://apis.io/badge/alleghany/card.svg"
alt="Alleghany Corporation Kin Score — API readiness rating by API Evangelist" width="340" height="120" loading="lazy">
</a>More shapes, themes and sizes → · Score as JSON · How badges work
How we profile Alleghany Corporation
Each block below is one kind of artifact we hold for Alleghany Corporation. For each we say what it is and why it earns a place in the profile, then list every one we've indexed — capped at two rows, scroll within the panel for the rest.
Security Posture 1
Authentication, domain security, vulnerability disclosure, and trust-center signals — the evidence that a provider takes security seriously enough to document it. We profile it because you can't govern what you can't see.
Authentication, domain security, vulnerability disclosure, and trust-center signals.
Resources
Every other property we hold for Alleghany Corporation — documentation, portals, status pages, policies, and corporate surface — grouped by the job it does, following the integrator's arc from getting started to running in production.
Get Started 1
Portal, sign-up, and the first successful call
Build 1
SDKs, sample code, and the tooling you integrate with
Access & Security 1
Authentication, authorization, and security posture
Operate 2
Status, limits, changes, and where to get help
Company 1
The organization behind the API
Other 5
Properties that don't map to a standard resource type
← All providers · Data indexed from github.com/api-evangelist/alleghany · machine-readable index on apis.io
This is an independent, third-party profile of Alleghany Corporation, published by API Evangelist. We do not operate, host, resell, or support these APIs, and we are not affiliated with or endorsed by the company unless stated above. Everything here is built from publicly available information — the company's own site, developer portal, documentation, public repositories, and the specifications it publishes for public use. Nothing is obtained by breaching a system, defeating an access control, or using credentials.
The Kin Score and Agent Readiness rating are independently calculated assessments of a company's public API artifacts, scored against a published rubric. They are not certifications, endorsements, security assessments, or audits.
Corrections, re-scores, and removal are free — no partnership or purchase required, and you do not need to justify the request. A removed company is recorded as unrated, never scored zero for having asked. Acknowledgement within one business day; removal within two.
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