Google and Speakeasy open-source the Gemini API SDK generator

Google has open-sourced the tool it uses to turn its API specifications into client libraries, and the reason is a supplier that vanished. In a post on the Google Developers Blog on 17 September, engineers Amir Hardon and Philipp Schmid said Speakeasy's full OpenAPI code generation suite is now available under the AGPLv3 licence, after the two companies worked together on the new Google GenAI SDKs for the Interactions, Agents and Webhooks APIs.

A shutdown in May forced the decision

Google says it was preparing for Google I/O and the general availability of the Interactions API in May 2026 when the proprietary provider it used for SDK generation was acquired and abruptly announced that it was closing. The company calls that episode evidence that closed-source generators create unacceptable platform risk, and argues that if the industry relies on OpenAPI to define its interfaces, the tooling that compiles those interfaces into client libraries, command-line tools and agent tools should be open infrastructure.

What is actually being released

The suite does three jobs. Multi-language generators produce client libraries for Python, TypeScript, Go, Java, C#, PHP and Ruby, each with static typing, server-sent event streaming, retries and pagination. An agent-native CLI generator compiles standalone command-line binaries, so a coding agent can call an API straight from a terminal session instead of writing disposable scripts. A documentation MCP server generator turns OpenAPI specifications and markdown documentation into a Model Context Protocol server, which lets an agent query live, verified schemas rather than guessing at methods that no longer exist.

The licence applies to the generator, not the output

AGPLv3 is the deliberate part of the release. Google says developers can run the generator in a development or continuous integration pipeline and keep full ownership of the generated code and SDKs under whatever licence they choose, such as MIT or Apache 2.0, while any modification to the generator compiler itself stays open. Google also says the migration involved aligning type definitions across every target language, preserving strict error hierarchies and streaming behaviour, and folding the generator into its internal build system. The pipeline now covers six targets with roughly one engineer maintaining it, where handcrafted generators previously consumed several.

Our opinion

This is a supply-chain story wearing a tooling announcement's clothes, and the interesting detail is not the language list. A single acquisition in May was enough to freeze the SDK pipeline for the APIs Google had spent months selling to developers, which is a remarkable amount of exposure for a company that treats its API surface as a product. Choosing AGPLv3 is the sharpest part of the response: Google gets to keep its own SDKs under whatever permissive licence suits it, while anyone who improves the generator itself has to publish those improvements. That is an unusually direct answer to a vendor risk problem, and it quietly makes the generator's future everybody else's problem to maintain as well. The unresolved question is who actually owns the tool now. Speakeasy's commercial business sits alongside a generator that anyone can fork, and the announcement does not explain how the two are meant to coexist. For the rest of the industry the lesson is blunter than the blog post admits: if your build pipeline depends on one closed-source supplier, you have already outsourced your release schedule to someone else's balance sheet.