Marshmallow
Marshmallow is a London-headquartered UK insurtech founded in 2017 by twins Alexander and Oliver Kent-Braham with engineer David Goate, built around a single underserved segment: people who have recently moved to the United Kingdom. Traditional UK motor underwriters ignore overseas driving history and price newcomers punitively, so Marshmallow built its own pricing, fraud and underwriting models that consume global rather than only national driving data. It is one of the small number of UK insurtechs that owns the whole value chain rather than renting a carrier's paper: Marshmallow Financial Services Limited distributes and is authorised and regulated by the Financial Conduct Authority (FRN 797672), Marshmallow Credit Services Limited holds a separate FCA authorisation (FRN 1024606) for its car-finance product, and Marshmallow Insurance Limited is an authorised insurance undertaking regulated by the Gibraltar Financial Services Commission that underwrites motor risk and files an annual Solvency and Financial Condition Report. Lines of business are private motor and telematics motor, van, home (buildings, contents and personal possessions) and car finance, sold direct-to-consumer through an app and web quote flow with offices in London and Budapest. The company reached unicorn valuation in 2021 and was ranked Europe's second fastest-growing company by the Financial Times in 2023. Its API posture is honest and narrow: Marshmallow publishes NO public, self-serve developer portal and NO downloadable OpenAPI. There is no developer., developers. or api-docs surface; api.marshmallow.com and docs.marshmallow.com exist but return 403 to anonymous callers, and account.marshmallow.com / app.marshmallow.com are consumer login walls. The only anonymously reachable machine-readable artifact is an OpenID Connect discovery document at auth.marshmallow.com, which advertises authorization-code with PKCE, client-credentials, refresh-token and token-exchange grants, mTLS client authentication and certificate-bound tokens, and publishes only the openid scope — real OAuth infrastructure serving Marshmallow's own apps and partners, with no public client registration. Marshmallow is therefore a technology-first insurer whose APIs are entirely internal and partner-gated, and no ACORD, AL3, ACORD XML or NGDS reference appears anywhere on its public properties.
More than an index entry, but the surface is still mostly links rather than artifacts — the cohort most likely to move a full band from modest, well-targeted work.
API Evangelist profiles Marshmallow the way a machine reads it — 3 machine-readable artifacts, 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 — Marshmallow scores 22.1/100 (emerging), with a separate agent-readiness read of 11/100 (agent aware). 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 2026-09-08 · rubric v0.20.0
Put this on your own site. The badge is drawn live from Marshmallow's current Kin Score — paste it once and it updates itself every time the score is recomputed. It follows your visitor's light or dark setting, and it links back here so anyone who sees it can read the full breakdown.
<!-- Kin Score · API Evangelist -->
<a href="https://providers.apievangelist.com/providers/marshmallow/"
title="Marshmallow on API Evangelist — API profile and Kin Score">
<img src="https://apis.io/badge/marshmallow.svg"
alt="Marshmallow Kin Score — API readiness rating by API Evangelist" width="150" height="150" loading="lazy">
</a>[](https://providers.apievangelist.com/providers/marshmallow/)<!-- Kin Score · API Evangelist -->
<a href="https://providers.apievangelist.com/providers/marshmallow/"
title="Marshmallow on API Evangelist — API profile and Kin Score">
<img src="https://apis.io/badge/marshmallow/card.svg"
alt="Marshmallow 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 Marshmallow
Each block below is one kind of artifact we hold for Marshmallow. 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 2
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.
Scopes 1
OAuth scopes are the vocabulary of least-privilege access. Profiling them shows exactly what an integration — or an agent acting on a user's behalf — is allowed to do.
OAuth scopes governing access to this provider's APIs.
Resources
Every other property we hold for Marshmallow — 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
Agent Surfaces 2
MCP servers, agent skills, and machine-readable catalogs
Design & Contract 2
Pagination, idempotency, versioning, errors, and events
Build 2
SDKs, sample code, and the tooling you integrate with
Access & Security 4
Authentication, authorization, and security posture
Operate 1
Status, limits, changes, and where to get help
Commercial 2
Pricing, plans, and the legal terms of use
Company 4
The organization behind the API
Other 4
Properties that don't map to a standard resource type
← All providers · Data indexed from github.com/api-evangelist/marshmallow · machine-readable index on apis.io
This is an independent, third-party profile of Marshmallow, 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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