Versions & compatibility

SubEtha is a local, non-production proof of concept. This page records the protocol scope, the package versions verified against the public registries, and the license boundaries that constrain how the pieces may be used. All version facts below were checked against the live registries on 2026-07-27 (UTC) and are re-checked automatically by this site’s drift probe.

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 2026-07-27)applies to @subetha/provider 0.1.0 (npm, verified 2026-07-27)applies to subetha 0.2.0 (PyPI, verified 2026-07-27)

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	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 private and workspace-internal: it is not published to npm (the registry answers 404 for it — verified 2026-07-27), its package.json at the pinned commit is marked "private": true, and there is no supported package-manager install path for it. It is operated only from the product repository source, built inside that workspace (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

How these facts were verified

Versions and tags were read from the public registries (npm view … dist-tags versions license, PyPI JSON API) on 2026-07-27 (UTC), and the license/scope statements from the product repository at pinned commit 638fa1e. CI’s drift probe re-compares every VersionBadge fact on this site against the live registries; a stated version that stops being latest turns the probe red until the page is re-verified.