StopLight
AcquiredTechstars '15Austin, US Β· 5 known investors
Stoplight is a collaborative platform for API design that helps teams build and manage APIs at scale. The platform serves developers and engineering teams building scalable API programs.
Also known as Stoplight Β· Stoplight Platform Β· stoplight.io
Founders & leadership
Investors Β· 5
Also in the syndicate Β· 1
Company profile
researched Aug 2026Stoplight is an API technology company offering a software-as-a-service platform and open source tools for designing, documenting and governing APIs. The Stoplight Platform provides a visual editor for creating OpenAPI descriptions and JSON Schemas, automatically generated and editable interactive documentation, hosted mock servers derived from API descriptions, reusable component libraries, shared style guides, and a central repository of API design assets layered on top of Git and other version control systems. The product is positioned around a "design-first" workflow intended to let technical and non-technical stakeholders collaborate on API designs before implementation, and the company describes its API design technology as patented.
Alongside the commercial platform, Stoplight maintains widely used open source projects: Spectral, a JSON/YAML linter for automated style guides with support for OpenAPI 3.1/3.0/2.0, Arazzo 1.0 and AsyncAPI 2.x; Prism, which turns OpenAPI 2/3 and Postman Collection files into mock servers with transformations and validations; and Elements, embeddable React or Web Components for building interactive API documentation from OpenAPI and Markdown. The company's GitHub organization hosts roughly 125 repositories, with Prism, Spectral and Elements each in the thousands of stars.
Stoplight was founded by Marc MacLeod in 2015 and is remote-first, based in Austin, Texas. In August 2023 SmartBear entered a definitive agreement to acquire the company, combining Stoplight's governance, mocking and no-code/visual editing with SmartBear's API design, documentation and portal products; SmartBear said it expected to begin integrating Stoplight features into its core offerings in the first half of 2024 while Stoplight customers retained access to the platform.
Founding story
Stoplight was founded by Marc MacLeod in 2015 with the stated goal of enabling organizations to take a strategic, intentional approach to APIs. Its flagship product, Stoplight Studio, launched in the fall of 2019 as a tool to design, develop and document APIs, followed by the broader Stoplight Platform in June 2020, which added integration of API design with existing workflows and self-service sign-up.
Business model
Subscription SaaS sold in self-service tiers plus an annual-contract enterprise offering. Published plans include a free trial and Basic ($44/month annually billed, $56/month monthly, first 3 users free), Startup ($113/$147 per month, first 8 users free), and Pro Team ($362/$453 per month, first 15 users free) tiers with per-additional-user pricing, and an Enterprise plan with custom pricing, invoicing, custom payment terms and priority support. Higher tiers add private projects, multi-branch support, custom domains and theming, shared style guides, self-hosted Git providers, activity logs, LDAP and SAML SSO, and component libraries.
Recurring per-workspace/per-seat subscription fees across Basic, Startup and Pro Team plans, with negotiated annual contracts for Enterprise customers; open source tools (Spectral, Prism, Elements) are distributed free under Apache-2.0 licensing.
Traction
By February 2021 the company reported more than 600 customers worldwide and a greater than 200% increase in active users in the six months following the June 2020 platform release. Its open source repositories had roughly 5,000 stars (Prism), 3,189 stars (Spectral) and about 2,454 stars (Elements). SmartBear stated that Stoplight's Prism, Spectral and Elements communities joined SmartBear's Swagger, SoapUI and Pact communities for a combined open source developer network in the tens of millions.
Latest developments
SmartBear agreed to acquire Stoplight in August 2023, with feature integration into SmartBear's API design, documentation and portal products planned for the first half of 2024. The Stoplight website and blog now operate under SmartBear Software, and support has moved to the SmartBear Community. In August 2026 SmartBear published an update on Spectral following the compromise of the AsyncAPI organization on 2026-07-14 in a supply chain attack referred to as Miasma.
βΈFull profile β market position, technology, go-to-market, geography, history, risks & controversies
Market position
Positioned as a design-first API platform spanning design, mocking, linting and governance. SmartBear characterized Stoplight as a global API design-first company whose governance, mocking and no-code editing complement SmartBear's design, documentation and portal capabilities; IDC's Melinda-Carol Ballou described Stoplight's governance focus as complementary to SmartBear's portfolio. Stoplight was recognized in multiple 2023 Gartner Hype Cycle reports and repeatedly cited as a leader in API design by G2.
Design-first workflow with a visual OpenAPI/JSON Schema editor usable by non-technical stakeholders, a central Git-backed source of truth for API design assets, enforced style guides and reusable component libraries for consistency, instant mock servers, and a large open source footprint (Spectral, Prism, Elements) feeding the commercial platform.
Technology
OpenAPI- and JSON Schema-centric tooling: a visual/no-code specification editor, automatic interactive documentation generation from OpenAPI plus editable Markdown, style-guide linting, dependency and change tracking, Git-based storage of design assets, and hosted mock servers generated from API descriptions. Open source components are primarily TypeScript. The company states its API design technology is patented.
Go-to-market
Product-led self-service motion β free sign-up, 14-day trials and an interactive desktop demo β combined with an enterprise sales team for annual contracts. Demand generation runs through the Stoplight blog, guides, webinars, a podcast (The API Intersection), and large open source developer communities around Spectral, Prism and Elements. Support is delivered via the SmartBear Community.
Developers, architects and engineering teams building API programs, from individual designers to large enterprises running hundreds or thousands of internal and external APIs, including organizations in financial services, technology, healthcare and transportation. Named customers and referenced users include Calendly, PagerDuty, wefox, Zoom and Humana.
Geography
Remote-first company headquartered in Austin, Texas, serving customers worldwide; acquirer SmartBear is based in Somerville, Massachusetts.
History
After its 2015 founding by Marc MacLeod, Stoplight shipped Stoplight Studio in autumn 2019 and the Stoplight Platform in June 2020. Steve Rodda joined as chief executive officer in July 2020, and the company added its first chief technology officer, Jason Harmon, plus a chief operations officer (Jason Miller) and chief marketing officer (Ann Boyd). Next Coast Ventures and Bill Wood Ventures co-led funding in January 2020 and again in February 2021, when an $11M follow-on Series A brought total funding to $21M. The company was recognized in multiple 2023 Gartner Hype Cycle reports and by G2 across four consecutive quarters, and won Austin Business Journal best-place-to-work awards in 2022 and 2023 and an Austin Chamber A-List Early Stage award in 2021. In August 2023, with Harrison Yeager as CEO, SmartBear agreed to acquire Stoplight.
Risks & controversies
A July 14, 2026 compromise of the AsyncAPI organization, part of a supply chain attack labelled Miasma, prompted SmartBear to publish an update concerning Spectral, the Stoplight-originated linter that supports AsyncAPI.
Compiled by commissioned research from 8 cited public sources β announcements, filings, and press listed under research sources below.
Key figures
latest reportedCompany-reported or press-reported figures, each dated to when it was claimed β not independently audited.
Competitors Β· 7
by search overlap
Companies competing with StopLight for the same Google search keywords, organic and paid, via search-intersection analysis.
Timeline Β· 10
launches, deals, and filingsSmartBear entered a definitive agreement to acquire Stoplight, combining Stoplight's API governance, mocking and no-code editing with SmartBear's API design, documentation and portal capabilities; integration into SmartBear's core offerings was expected in the first half of 2024.
Stoplight announced an $11M follow-on Series A co-led by Next Coast Ventures and Bill Wood Ventures, bringing total funding to date to $21M, to be used for engineering capacity and marketing/customer engagement.
$11M source β
Steve Rodda joined Stoplight as chief executive officer in July 2020; the company also hired its first CTO Jason Harmon, COO Jason Miller and CMO Ann Boyd.
Release of the Stoplight platform, enabling integration of API design with existing workflows and self-service sign-ups.
Stoplight launched its flagship product Stoplight Studio in the fall of 2019 for designing, developing and documenting APIs.
Dated company events from announcements, filings, and press; legal rows summarize public dockets and regulator releases.
βΈResearch sources Β· 8
primary sources listed
- StopLightstoplight.io Β· web
8 public sources were cited for this profile; the first-party ones are listed here.
Frequently asked questions
- What does StopLight do?
- Stoplight is an API design-first SaaS platform for designing, documenting and governing OpenAPI-based APIs; acquired by SmartBear.
- Who founded StopLight?
- StopLight was founded by Marc MacLeod.
- Who are StopLight's investors?
- StopLight's investors include Next Coast Ventures, NextGen Venture Partners, Social Starts, Techstars.
- Where is StopLight headquartered?
- StopLight is headquartered in Austin, US.