A2A Project (Google-initiated)

license

Apache-2.0(OSI)

source

public(spec + reference SDKs in 6 languages)

governance

Linux Foundation (vendor-neutral, Google-contributed)

core-gated

ungated(the Linux Foundation project sells nothing - one Apache-2.0 LICENSE at the root, no ee/ or enterprise/ path, and all six reference SDKs published as public a2aproject repos on public package registries)

Reference spec and SDKs are Apache-2.0 under neutral LF governance; for a protocol this is the openness ceiling. Nothing is gated, established by a direct read of the repo: the finding rests on there being nothing to gate with rather than on a pricing page saying so. The root tree is LICENSE, GOVERNANCE.md, MAINTAINERS.md, specification/, docs/ and adrs/ with no ee/, enterprise/ or commercial/ path, and the README's closing section reads "The A2A Protocol is an open source project under the Linux Foundation, contributed by Google. It is licensed under the Apache License 2.0 and is open to contributions from the community." All six reference SDKs are separate public a2aproject repos installable from public registries - a2a-sdk on PyPI, github.com/a2aproject/a2a-go, @a2a-js/sdk on npm, Maven, NuGet and a2a-lf on crates.io. There is no vendor product beside the protocol, so there is no paid tier, no license key and no closed package.

• https://github.com/a2aproject/A2A recorded 2026-06-04

  Apache-2.0 license, LF-hosted open protocol, spec v1.0.1 + 6-language SDKs, ~24k stars

• https://api.github.com/repos/a2aproject/A2A recorded 2026-08-12

  Repo metadata: license spdx_id Apache-2.0, default branch main, 25,300 stars, not archived.

• https://api.github.com/repos/a2aproject/A2A/contents recorded 2026-08-12

  Root tree. LICENSE, CODE_OF_CONDUCT.md, CONTRIBUTING.md, GOVERNANCE.md, MAINTAINERS.md, SECURITY.md, adrs, docs, scripts, specification. No ee/, enterprise/, commercial/ or proprietary/ path, and no second LICENSE anywhere at the root.

• https://raw.githubusercontent.com/a2aproject/A2A/main/README.md recorded 2026-08-12

  Closing section: "The A2A Protocol is an open source project under the Linux Foundation, contributed by Google. It is licensed under the Apache License 2.0 and is open to contributions from the community." The SDK list links six separate public repos - a2a-python (pip install a2a-sdk), a2a-go, a2a-js (npm), a2a-java (maven), a2a-dotnet (NuGet) and a2a-rs (cargo add a2a-lf). No paid tier, hosted service or enterprise edition is mentioned.