myinvois

Unofficial Python SDK for the Malaysian MyInvois (LHDN) e-Invoice system.

Status: Beta. The full pipeline — build → sign → submit → track — is implemented and covered by tests, including golden-file tests that pin the serialized and signed output byte-for-byte. Not yet verified end-to-end against a live LHDN environment — see Scope and limitations. See AGENTS.md for architecture and detailed notes.

Features

• Typed client — sync MyInvoisClient and async AsyncMyInvoisClient, OAuth2 client_credentials with proactive token refresh, intermediary (onbehalfof) support, and a typed error hierarchy mapped to HTTP status.
• All the read endpoints — document types, document raw/details/recent/search, notifications, TIN validation/search/QR lookup.
• All eight document types — invoice, credit/debit/refund notes and their self-billed variants, each a named class that fixes its own type code.
• UBL 2.1 document models — Pydantic v2, Decimal money, LHDN code enums.
• Serializers — canonical UBL JSON and XML envelopes, both pinned byte-for-byte by golden-file tests.
• XAdES signing — XmlSigner / JsonSigner, output likewise pinned byte-for-byte.
• Submit + lifecycle — submit documents, poll submission status, cancel and reject.
• Bundled code tables — 3,637 rows of LHDN enumerated lists shipped as data.

Install

uv add myinvois      # or, with pip: pip install myinvois

Requires Python 3.11+.

Quickstart

from myinvois import MyInvoisClient, Environment

client = MyInvoisClient(
    client_id="YOUR_CLIENT_ID",
    client_secret="YOUR_CLIENT_SECRET",
    environment=Environment.SANDBOX,
)
client.login()                      # OAuth2 client_credentials
print(client.access_token)

# Read-only examples
types = client.document_types.list()
details = client.documents.get_details(uuid="...")
recent = client.documents.get_recent_documents(page_size=50)
results = client.documents.search_documents(
    submission_date_from="2024-01-01T00:00:00Z",
    submission_date_to="2024-01-31T00:00:00Z",
)

# Validate a Tax Identification Number before issuing an invoice
ok = client.taxpayer.validate_tin(tin="C2584563222", id_type="BRN", id_value="202001234567")

# Intermediary / ERP systems submitting on behalf of a taxpayer:
client.login(on_behalf_of="C1234567890")

MyInvoisClient is a context manager, so with MyInvoisClient(...) as client: closes the underlying httpx client for you.

Async

AsyncMyInvoisClient mirrors the sync client one-for-one — same constructor, same properties, same services. Only the I/O methods are coroutines.

import asyncio
from myinvois import AsyncMyInvoisClient, Environment

async def main() -> None:
    async with AsyncMyInvoisClient(
        client_id="...", client_secret="...", environment=Environment.SANDBOX
    ) as client:
        await client.login()
        recent = await client.documents.get_recent_documents(page_size=50)
        print(recent)

asyncio.run(main())

Build an invoice

UBL documents are Pydantic v2 models with snake_case attributes and exact UBL element names as serialization aliases. All money is Decimal.

from datetime import UTC, datetime
from decimal import Decimal

from myinvois.codes import Currency, DocumentTypeCode, MalaysianState
from myinvois.ubl import (
    AccountingParty, Address, AddressLine, CommodityClassification, Contact,
    Country, Invoice, InvoiceLine, Item, ItemPriceExtension, LegalEntity,
    LegalMonetaryTotal, Party, PartyIdentification, Price, TaxCategory,
    TaxScheme, TaxSubTotal, TaxTotal,
)

address = Address(
    city_name="Kuala Lumpur",
    postal_zone="50480",
    country_subentity_code=MalaysianState.WP_KUALA_LUMPUR,
    address_lines=[AddressLine(line="Lot 66, Bangunan Merdeka")],
    country=Country(identification_code="MYS"),
)

invoice = Invoice(
    id="INV-0001",
    issue_date_time=datetime(2024, 6, 14, 9, 30, tzinfo=UTC),
    invoice_type_code=DocumentTypeCode.INVOICE,
    document_currency_code=Currency.MYR,
    accounting_supplier_party=AccountingParty(
        additional_account_id="CPT-CCN-W-211111-KL-000002",
        party=Party(
            industry_classification_code=("01111", "Agriculture"),
            party_identifications=[PartyIdentification(id="C2584563222", scheme_id="TIN")],
            postal_address=address,
            legal_entity=LegalEntity(registration_name="AMS Setia Jaya Sdn. Bhd."),
            contact=Contact(telephone="+60123456789", electronic_mail="ams@supplier.com"),
        ),
    ),
    accounting_customer_party=AccountingParty(
        party=Party(
            party_identifications=[PartyIdentification(id="C2584563200", scheme_id="TIN")],
            postal_address=address,
            legal_entity=LegalEntity(registration_name="Hebat Group"),
            contact=Contact(telephone="+60123456789", electronic_mail="name@buyer.com"),
        ),
    ),
    tax_total=TaxTotal(
        tax_amount=Decimal("87.63"),
        tax_sub_totals=[
            TaxSubTotal(
                taxable_amount=Decimal("87.63"),
                tax_amount=Decimal("87.63"),
                tax_category=TaxCategory(id="01", tax_scheme=TaxScheme(id="OTH")),
            )
        ],
    ),
    legal_monetary_total=LegalMonetaryTotal(
        line_extension_amount=Decimal("1436.50"),
        tax_exclusive_amount=Decimal("1436.50"),
        tax_inclusive_amount=Decimal("1524.13"),
        payable_amount=Decimal("1524.13"),
    ),
    invoice_lines=[
        InvoiceLine(
            id="1",
            invoiced_quantity=Decimal("1"),
            line_extension_amount=Decimal("1436.50"),
            item=Item(
                description="Consulting services",
                commodity_classifications=[
                    CommodityClassification(item_classification_code="011", list_id="CLASS")
                ],
            ),
            price=Price(price_amount=Decimal("1436.50")),
            item_price_extension=ItemPriceExtension(amount=Decimal("1436.50")),
            tax_total=TaxTotal(
                tax_amount=Decimal("87.63"),
                tax_sub_totals=[
                    TaxSubTotal(
                        taxable_amount=Decimal("1436.50"),
                        tax_amount=Decimal("87.63"),
                        tax_category=TaxCategory(id="01", tax_scheme=TaxScheme(id="OTH")),
                    )
                ],
            ),
        )
    ],
)

The models enforce LHDN's structural rules at construction time — a missing commodity_classifications, tax_total or item_price_extension on a line raises a Pydantic ValidationError rather than being rejected by the server.

Document types

All eight MyInvois document types are supported. Each has a named class that takes the same fields as Invoice:

from myinvois.ubl import CreditNote

note = CreditNote(id="CN-0001", ...)   # same fields as Invoice
note.invoice_type_code                 # -> DocumentTypeCode.CREDIT_NOTE

Prefer these over setting invoice_type_code by hand. MyInvois carries every document type on the same Invoice envelope, distinguished only by that code — a credit note is byte-identical to an invoice apart from two characters. Invoice defaults the code to 01, so building a credit note with Invoice and forgetting the field produces a well-formed document that claims to be an invoice, with nothing in the payload to reveal the mistake. The named classes supply the right code for you, so omitting the field is safe, and passing a conflicting one raises.

For self-billed documents the buyer issues the document. The classes do not transpose accounting_supplier_party and accounting_customer_party for you — populate them per LHDN's rules; the supplier remains the supplier of the goods or services.

Serialize

from myinvois.ubl.builders import JsonEnvelopeBuilder, XmlEnvelopeBuilder

unsigned_json = JsonEnvelopeBuilder(invoice).build_json()  # str
unsigned_xml = XmlEnvelopeBuilder(invoice).build_xml()     # str, C14N-canonical

Both emit the canonical LHDN wire form (_D/_A/_B/_E namespace keys and array-of-one element wrapping for JSON; C14N-1.0 inclusive, no XML declaration and no inter-element whitespace for XML) enabling deterministic, reproducible signature digest computation. Live validator acceptance remains unverified (see Scope and limitations).

Sign (XAdES)

from datetime import UTC, datetime

from myinvois import CertConfig
from myinvois.ubl.signing import JsonSigner, XmlSigner

cert = CertConfig(
    private_key_path="/path/to/private_key.pem",
    certificate_path="/path/to/certificate.base64",  # raw base64-encoded DER, not PEM
)

signed_json = JsonSigner(cert).sign(unsigned_json, signing_time=datetime.now(UTC))  # str
signed_xml = XmlSigner(cert).sign(unsigned_xml, signing_time=datetime.now(UTC))     # bytes

Signing embeds the ext:UBLExtensions XAdES block and the cac:Signature sibling, and flips InvoiceTypeCode/@listVersionID from 1.0 to 1.1. Use .digests(...) instead of .sign(...) if you only need the individual cryptographic primitives (SignerDigests).

Submit and track

from myinvois.services.submissions import build_submission_payload

payload = build_submission_payload("INV-0001", signed_json)  # format auto-detected
response = client.submissions.submit_documents([payload])
print(response.submission_uid, response.accepted_documents, response.rejected_documents)

# Poll — LHDN validates asynchronously; 3-5s intervals are recommended.
status = client.submissions.get_submission(response.submission_uid)
print(status.overall_status)          # in progress / valid / partially valid / invalid
for doc in status.document_summary:
    print(doc.uuid, doc.status, doc.totals.total_payable_amount)

# QR code URL for a validated document
url = client.generate_document_qr_code_url(id_="INV-0001", long_id="<longId from LHDN>")

Cancel / reject

client.documents.cancel_document(uuid="...", reason="Wrong buyer TIN")   # issuer, 72h window
client.documents.reject_document(uuid="...", reason="Incorrect amount")  # receiver, 72h window

Both return a DocumentStateChangeResponse. LHDN returns logical rejections (e.g. OperationPeriodOver, IncorrectState) with HTTP 200 and a populated .error block — check it. Transport-level failures raise typed MyInvoisError subclasses instead.

Code tables

The library bundles the LHDN enumerated lists (3,637 rows total):

from myinvois.codes import (
    MalaysianState, TaxType, PaymentMethod, DocumentTypeCode, Currency,
    ClassificationCode, Country, MSIC, UnitCode,
)

TaxType.description_for("02")                       # -> "Service Tax"
DocumentTypeCode.SELF_BILLED_INVOICE.is_self_billed # -> True
DocumentTypeCode.coerce("03")                       # -> DEBIT_NOTE
Country.name_for("MYS")                             # -> "MALAYSIA"
MSIC.row_for("01111")["description"]                # -> "Growing of maize"

Scope and limitations

• The wire format is reverse-engineered. LHDN publishes the API and UBL specifications but does not ship an official SDK in any language. The canonical byte-level details here (JSON envelope shape, XML canonicalisation, XAdES digest inputs) were derived from LHDN's documentation and frozen as golden fixtures. Those tests prove the output is deterministic and unchanged, not that LHDN's validator accepts it.

• Signing is verified against fixtures, not against LHDN. The XAdES output is pinned byte-for-byte against golden fixtures, and its element structure matches LHDN's own published signed sample (element paths, not every attribute value). But no document has been signed with a CA-issued certificate and accepted by LHDN's validator, because signing requires a certificate from an approved Malaysian CA. Producing a signature LHDN accepts is therefore unproven. If you are evaluating this library for production use, this is the risk to weigh.

• What has been verified live: authentication and the read-only endpoints, against the preprod sandbox — token issuance, document-type listing and TIN validation all round-trip and parse correctly. Submission has not been exercised. See tests/live/.

• Signing requires a certificate issued by an approved Malaysian CA — LHDN does not issue them. The SDK never reads credentials implicitly; you pass a CertConfig explicitly.

Development

uv sync
uv run pytest
uv run ruff check . && uv run ruff format --check .
uv run mypy src/myinvois

Live tests are marked @pytest.mark.live and skip unless MYINVOIS_CLIENT_ID is set. The project follows TDD, with golden-file tests pinning the UBL and signature output byte-for-byte.

Roadmap

Phases 0–6 are complete: scaffold, client + auth, read services, code tables, UBL models, JSON + XML serializers, XAdES signing, submit + state services, and the async mirror. See AGENTS.md for the full phase-by-phase record.

Remaining before 1.0:

• Trusted-Publishing release to PyPI. (CI is in place: ruff, mypy and the test suite run on Python 3.11–3.13, plus a check that the built wheel and sdist ship the code tables and no signing material.)
• Live submission to the LHDN preprod sandbox. Authentication and the read-only endpoints are already verified there; submitting a signed document needs a certificate from an approved Malaysian CA, so signing remains fixture-verified only.

Disclaimer

myinvois is an independent community project and is not affiliated with, or endorsed by, the Inland Revenue Board of Malaysia (LHDN). "MyInvois" is a trademark of its respective owner.

License

MIT