MonetaKit Contrib

Community-maintained extensions for MonetaKit, hosted by the MonetaKit org: PSP adapters beyond the core set, and country-specific invoicing and tax-filing formats.

Support tiers

Tier	Lives in	Maintained by	Gate
core	monetakit/monetakit (adapters/)	MonetaKit team	—
contrib	this repo	community, org-reviewed	certification battery green + code review
community	author's own repo	author	listed in the docs registry, certification self-reported

Everything in this repo is community-supported: the MonetaKit team reviews and merges, but does not guarantee fixes on any timeline. An adapter that becomes load-bearing and well-maintained can graduate to core; an unmaintained one gets archived rather than silently shipped.

Layout

One directory per PSP, everything about that PSP together — whatever the language (why):

adapters/
├── example/         minimal compiling skeleton (copy to start)
└── paypay/          the full reference implementation
    ├── *.go         Go adapter (implements adapterkit.PaymentProvider)
    ├── capability.json
    ├── vectors/     language-neutral fixtures: gateway, webhooks, certify
    ├── ts/          TS twin — npm workspace @monetakit/paypay
    └── MAINTAINERS
invoicing/           country e-invoice formats (data-first)
tax/                 tax-filing / reporting formats (data-first)

Quality model: declare → enforce → certify

An adapter declares what its PSP supports in capability.json / Capabilities() (currencies and charge bounds, charge modes, catalog, metering…). Core enforces those declarations once for everyone (moneta plan rejects incompatible Planfiles at plan-time). The certification battery (adapterkit/certify in core) then derives a test suite from the declarations:

• Laws — invariants checked automatically: capability vocabulary, declared ⇔ implemented coherence, catalog-less no-ops, webhooks fail closed, undeclared currencies rejected before the network.
• Scenarios — named wire fixtures you supply (CHG-01 success, CHG-03 decline, CHG-04 transport failure, PSH-01 push action, …); the harness owns the assertions.

The catalog lives in core: adapterkit/certify/SCENARIOS.md. "Certify green" is the merge gate for adapters.

How adapters ship

Adapters run in-process with the engine/CLI, so the charge path is Go and implements the adapterkit.PaymentProvider contract. Once certified and merged here, a small PR in core wires the adapter into the moneta provider switch and it ships in the official binary, marked community-supported. A TS twin (adapters/<psp>/ts, published as @monetakit/<psp>) is optional and adds client/edge-side support — it must replay the same vectors/ files as the Go adapter so the two cannot drift.

Developing

go.mod pins core's tagged release (currently v0.0.2, the adapterkit compatibility anchor) — a plain go build fetches it like any module:

git clone git@github.com:MonetaKit/contrib.git
cd contrib
make check    # Go: fmt + vet + build + test
npm install && npm test && npm run typecheck   # TS workspaces (adapters/*/ts)

To develop against unreleased core changes, add a local override (don't commit it): go mod edit -replace github.com/monetakit/monetakit=../monetakit

Versioning & releases

• Go adapters version together with this repo's tag.
• TS packages (adapters/*/ts) are independent npm workspaces under the @monetakit scope. Nothing is published to npm yet — the publish pipeline is tracked in monetakit#6.
• Every PR updates [Unreleased] in CHANGELOG.md.

Contributing

See CONTRIBUTING.md. Short version:

• PSP adapter — start from adapters/example/, model the result on adapters/paypay/; declare honest capabilities; pass the certification battery; ship language-neutral vectors.
• Invoicing / tax format — you don't need to write Go. Contribute the spec as data: field mappings, schemas, and golden test vectors. See invoicing/README.md.

License

MIT, same as core.