Versions & compatibility

This page records SubEtha’s protocol scope, the package versions verified against the public registries, and the license boundaries that constrain how the pieces may be used. The source-commit verification for this page is dated 2026-08-05. The registry snapshots below were re-checked on 2026-08-07 (UTC); the drift probe automatically re-checks the three VersionBadge facts, while auxiliary registry claims remain manual checks. See How these facts were verified for the source and registry verification boundaries.

Protocol scope

• x402 v2 only. SubEtha’s payment surface is the official x402 v2 protocol; the scheme is subetha-zerc20 and everything SubEtha-specific rides inside the standard extension points. There is no x402 v1 (X-PAYMENT) fallback.
• MPP is deferred. The official path runs x402 only; MPP framing is explicitly deferred in the product at the pinned commit (docs/OVERVIEW.md).
• Additive-only evolution. For x402Version: 2, the scheme name, the payload discrimination rule, and the meaning of settle (= accepted) are frozen; new optional fields may appear in extra, payloads, and responses, and unknown keys must be ignored (see the wire protocol reference).

Published packages

applies to @subetha/x402-scheme 0.1.0 (npm, verified 2026-08-07)applies to @subetha/provider 0.1.0 (npm, verified 2026-08-07)applies to subetha 0.2.0 (PyPI, verified 2026-08-07)

package	registry	latest	license	role
@subetha/x402-scheme	npm	0.1.0 (only published version; latest and next tags)	Apache-2.0	payer-side scheme handler, wire types, fee interpretation — TypeScript API
@subetha/provider	npm	0.1.0 (only published version; latest and next tags)	Apache-2.0	provider-side scheme server, payment handler, facilitator HTTP client — TypeScript API
subetha	PyPI	0.2.0 (published: 0.1.0, 0.2.0)	Apache-2.0 in the repository; PyPI JSON license is null	payer-side reference client — Python API

All three are 0.x, experimental: APIs may change in breaking ways between 0.x minor releases. The Python package’s README at the pinned commit still recommends the pin subetha>=0.1,<0.2, which excludes the 0.2.0 release that is current on PyPI — see the Python API reference for the documented divergence.

The facilitator is source-only

subetha-facilitator is the private workspace daemon package in apps/facilitator (private: true). The separate @subetha/facilitator workspace library under packages/facilitator is also not published to npm (the registry answered 404, verified 2026-08-07), but it is not the daemon entrypoint. Neither artifact has a supported package-manager installation path for running the facilitator; it is built and operated from product source. See docs/FACILITATOR.md. The configuration reference documents its config surface; nothing on this site installs it from a registry.

License boundaries

• SubEtha’s own code is Apache-2.0 — the SubEtha-authored sources under apps/, packages/, and contracts/ (including PermitBurner.sol), and the three published packages above.
• @zerc20/sdk is BUSL-1.1 (Business Source License 1.1), not Apache-2.0. The product repository references it as a local link and does not vendor, copy, or redistribute the SDK source; this documentation repository likewise contains no @zerc20/sdk code. BUSL-1.1’s Additional Use Grant is None, so production or commercial use of the zERC20 dependency requires a commercial license obtained directly from the zERC20 licensor. SubEtha’s Apache-2.0 license grants no rights to the zERC20 toolchain.
• The full statement, including the name/official-status notice, is the product README’s License section. This page is a summary, not legal advice.

Toolchain floor (published packages)

surface	requirement
@subetha/x402-scheme, @subetha/provider	Node.js >= 20, ESM-only; peer dependency @x402/core ^2.17.0
subetha (PyPI)	Python >= 3.11; depends only on httpx, eth-account, eth-utils; repository license Apache-2.0; PyPI registry license metadata is null

How these facts were verified

Versions and tags were read from the public registries (npm view … dist-tags versions license, PyPI JSON API) on 2026-08-07 (UTC), and the license/scope statements from the product repository at verified commit 85fd50ac. CI’s drift probe re-compares each VersionBadge fact on this site against the live registries; auxiliary table facts such as tag completeness, PyPI metadata, and the facilitator 404 remain manual verification items. A stated badge version that stops being latest turns the probe red until the page is re-verified.