e2e

One command typed in a project folder, npx e2e@latest init, is how developers begin with e2e, an open source testing framework built for the age of coding agents. The company behind it was founded as TesterArmy, went through Y Combinator, and renamed itself e2e in November 2026 after the framework became what developers knew it for. It has a team of six, with Szymon Rybczak as co-founder and CEO and Oskar Kwaśniewski as co-founder and CTO.

From a closed testing platform to tests kept as code

TesterArmy began as a hosted platform. According to the founders, the more customers they had, the more they ran into the limits of a closed system: tests could not live beside the code in a repository, customers could not choose their own model, and suites could not be run on a developer's machine next to the coding agent. The framework was their answer. Tests are TypeScript files in the repository, the model is the user's choice with their own API keys or subscriptions, and runs happen in a terminal or in continuous integration. The old platform is closed to new sign-ups and stays available to existing accounts until 15 January 2027, and the team says it will help customers move their tests across by rewriting them.

Mixing agent steps with exact assertions

A test in e2e can ask an agent to act in plain language, for example adding items to a cart and paying with a test card, and then check the result with precise locators and deterministic assertions. The same test can target web, iOS and Android. Steps that an agent has already verified are replayed from a cache, so repeat runs are quick and do not call the model again unless the steps change. The framework is released under the Apache-2.0 licence and works with coding agents such as Claude Code, Cursor and Codex.

Seed funding and community growth

On 3 November 2026 the company announced an $8 million seed round, naming Credo Ventures, KAYA, Point Nine, Baobab Ventures and Script Capital among its backers, together with a number of individual investors. It reports that the framework launched on 1 October 2026 and passed 1.5 million npm downloads and 12,000 GitHub stars in its first month, with 60 external contributors. The team is hiring in Warsaw and San Francisco, and plans a hosted e2e cloud for 2027 so teams can run tests on managed infrastructure, models and devices. Paid help is offered for migrating suites, custom builds and rollout in a customer's CI.

Key facts

Formerly: TesterArmy (renamed e2e in November 2026) Founded: 2026, as TesterArmy; framework launched 1 October 2026 People: Szymon Rybczak (co-founder, CEO); Oskar Kwaśniewski (co-founder, CTO) Team: six people, with offices or hiring in Warsaw and San Francisco Products or Services: open source e2e framework for web, iOS and Android; migration, custom build and rollout help; e2e cloud planned for 2027 Licence: Apache-2.0 Funding: $8 million seed round announced 3 November 2026 (Credo Ventures and others) Website: e2e.tester.army