PathBridge¶

PathBridge helps you translate validator-reported locations (XPath/JSONPath/JSON Pointer) back to your application model paths and build structured validation errors.

Why PathBridge¶

Validators report failures against document locations. Your application usually needs errors attached to facade or DTO fields. PathBridge bridges that gap:

• Compile destination-to-facade mapping rules once.
• Translate runtime validator locations quickly.
• Emit nested error dictionaries compatible with Marshmallow-style structures.
• Prefer automation over manual rules: make_shape (shaper) and build_rules (tracer) can generate mappings from your destination classes and converter.

Install¶

pip install pathbridge

Quick Start¶

from pathbridge import compile_rules, translate_location, to_marshmallow

rules = {
    "Return[1]/Contact[1]/Phone[1]": "person/phones[0]",
    "Return[1]/Contact[1]/Phone[2]": "person/phones[1]",
}

compiled = compile_rules(rules)
location = "/Return[1]/Contact[1]/Phone[2]"

print(translate_location(location, compiled))
# person/phones[1]

errors = to_marshmallow([(location, "Invalid phone")], compiled)
# {"person": {"phones": {1: ["Invalid phone"]}}}

Next Steps¶

• Read Getting Started for path-matching behavior and usage details.
• Use Extras to generate rules by tracing your converter automatically.
• Use the CLI to generate importable Python modules with compiled rules.
• Explore Real-life Examples for HMRC MTR, OpenAPI, and ISO 20022 integrations.