pacs008 API reference

pacs008 offers a REST API, CLI, and Python library for payment validation, XML generation, and repeatable release workflows. Teams can use the same rules in local tests and live services.

Implementation notes

Start with the smallest path that fits the workflow.

Use one path for local checks, one for service runs, and one for embedded code.

• Use sync generation for quick checks.
• Use async generation for large files.
• Keep the input payload and validation report together.

Installation

Install the package from PyPI. Requires Python 3.10 or later.

python -m pip install pacs008
 

---

REST API

Start the FastAPI server to validate payment data and generate XML.

Start the server

uvicorn pacs008.api.app:app --reload --host 0.0.0.0 --port 8000
 

Endpoints

See Message Types for the full list of supported message pages.

Validation example

Validate payment data before generating XML.

curl -X POST http://localhost:8000/api/validate \
  -H "Content-Type: application/json" \
  -d '{
    "message_type": "pacs.008.001.13",
    "data": [{
      "msg_id": "MSG-2026-001",
      "creation_date_time": "2026-01-15T10:30:00",
      "nb_of_txs": "1",
      "settlement_method": "CLRG",
      "interbank_settlement_date": "2026-01-15",
      "end_to_end_id": "E2E-INV-2026-001",
      "interbank_settlement_amount": "25000.00",
      "interbank_settlement_currency": "EUR",
      "charge_bearer": "SHAR",
      "debtor_name": "Acme Corp GmbH",
      "debtor_agent_bic": "DEUTDEFF",
      "creditor_agent_bic": "COBADEFF",
      "creditor_name": "Widget Industries SA"
    }]
  }'
 

{
  "valid": true,
  "message_type": "pacs.008.001.13",
  "errors": [],
  "warnings": []
}
 

Synchronous generation example

Generate a pacs.008.001.13 XML file from JSON data.

curl -X POST http://localhost:8000/api/generate \
  -H "Content-Type: application/json" \
  -d '{
    "message_type": "pacs.008.001.13",
    "template": "pacs008/templates/pacs.008.001.13/template.xml",
    "schema": "pacs008/templates/pacs.008.001.13/pacs.008.001.13.xsd",
    "data": [{
      "msg_id": "MSG-2026-001",
      "creation_date_time": "2026-01-15T10:30:00",
      "nb_of_txs": "1",
      "settlement_method": "CLRG",
      "interbank_settlement_date": "2026-01-15",
      "end_to_end_id": "E2E-INV-2026-001",
      "tx_id": "TX-001",
      "interbank_settlement_amount": "25000.00",
      "interbank_settlement_currency": "EUR",
      "charge_bearer": "SHAR",
      "debtor_name": "Acme Corp GmbH",
      "debtor_agent_bic": "DEUTDEFF",
      "creditor_agent_bic": "COBADEFF",
      "creditor_name": "Widget Industries SA"
    }]
  }' --output pacs008_output.xml
 

Asynchronous generation

For large files, submit an async job and poll until it finishes.

# Submit the job
JOB=$(curl -s -X POST http://localhost:8000/api/generate/async \
  -H "Content-Type: application/json" \
  -d '{"message_type":"pacs.008.001.13","data":[...]}')

JOB_ID=$(echo $JOB | jq -r '.job_id')

# Poll for completion
curl http://localhost:8000/api/status/$JOB_ID

# Download the result
curl http://localhost:8000/api/download/$JOB_ID --output result.xml
 

{
  "job_id": "8f7f0d4b-7df9-4d1a-8d47-19f4f28b6d38",
  "status": "completed",
  "message_type": "pacs.008.001.13",
  "download_url": "/api/download/8f7f0d4b-7df9-4d1a-8d47-19f4f28b6d38"
}
 

---

CLI

The CLI takes a data file, message version, template, and schema. It validates the input and writes XML to the output directory.

Basic usage

pacs008 -t  \
  -m  \
  -s  \
  -d 
 

Example

pacs008 -t pacs.008.001.13 \
  -m pacs008/templates/pacs.008.001.13/template.xml \
  -s pacs008/templates/pacs.008.001.13/pacs.008.001.13.xsd \
  -d payments.csv
 

Dry-run mode

Use --dry-run to validate input data without generating XML. The exit code shows whether validation passed (0) or failed (1).

pacs008 -t pacs.008.001.13 \
  -m pacs008/templates/pacs.008.001.13/template.xml \
  -s pacs008/templates/pacs.008.001.13/pacs.008.001.13.xsd \
  -d payments.csv \
  --dry-run
 

Add --verbose for detailed output during generation.

---

Python API

Use the library directly in Python scripts or services.

Generate XML from payment records

from pacs008 import generate_xml_string

payments = [{
    "msg_id": "MSG-2026-001",
    "creation_date_time": "2026-01-15T10:30:00",
    "nb_of_txs": "1",
    "settlement_method": "CLRG",
    "interbank_settlement_date": "2026-01-15",
    "end_to_end_id": "E2E-INV-2026-001",
    "tx_id": "TX-001",
    "interbank_settlement_amount": "25000.00",
    "interbank_settlement_currency": "EUR",
    "charge_bearer": "SHAR",
    "debtor_name": "Acme Corp GmbH",
    "debtor_agent_bic": "DEUTDEFF",
    "creditor_agent_bic": "COBADEFF",
    "creditor_name": "Widget Industries SA",
}]

xml = generate_xml_string(
    payments,
    "pacs.008.001.13",
    "pacs008/templates/pacs.008.001.13/template.xml",
    "pacs008/templates/pacs.008.001.13/pacs.008.001.13.xsd",
)
print(xml)
 

SWIFT compliance check

Check and clean data against SWIFT character and field-length rules before generation.

from pacs008.compliance import cleanse_data_with_report

raw = [{"debtor_name": "Müller & Söhne™", "msg_id": "X" * 50}]
clean, report = cleanse_data_with_report(raw)
print(report.summary())
 

---

Docker

Run the API in a container using the bundled Dockerfile.

docker build -t pacs008:latest .
docker run -p 8000:8000 pacs008:latest
 

docker run --rm   -e PACS008_LOG_LEVEL=INFO   -v $PWD/examples:/data   -p 8000:8000 pacs008:latest
 

---

IBAN and BIC validation

Validate financial identifiers independently of XML generation.

from pacs008.validation import validate_iban, validate_bic

is_valid, error = validate_iban("DE89370400440532013000", strict=False)
is_valid, error = validate_bic("DEUTDEFF", strict=False)
 

---

Streaming

Load large datasets in configurable chunks to limit memory usage.

from pacs008.data.loader import load_payment_data_streaming

for chunk in load_payment_data_streaming("large_payments.csv", chunk_size=500):
    print(f"Processing {len(chunk)} records")
 

from pacs008.validation import validate_batch

for chunk in load_payment_data_streaming("large_payments.csv", chunk_size=500):
    report = validate_batch(chunk, "pacs.008.001.13")
    print(report.summary())
 

---

Validation service

Run the full pre-generation validation pipeline programmatically.

from pacs008.validation import ValidationService, ValidationConfig

service = ValidationService()
report = service.validate_all(ValidationConfig(
    xml_message_type="pacs.008.001.13",
    xml_template_file_path="pacs008/templates/pacs.008.001.13/template.xml",
    xsd_schema_file_path="pacs008/templates/pacs.008.001.13/pacs.008.001.13.xsd",
    data_file_path="payments.csv",
))
print(report.is_valid, report.errors)
 

---

Required data fields

Each payment record must include these fields. Version-specific fields are listed below.

Version-specific fields