c2pa-python

library0.32.6pypypi✓ verified 88d ago

Python bindings for the C2PA Content Authenticity Initiative (CAI) library (v0.32.6, pre-1.0, monthly releases). Provides signing and verification of C2PA manifests for media provenance.

serialization auth-security

pip install c2pa-python

github ↗package ↗homepage ↗

INSTALL

IMPORT

SIG · C2PA-PYTHON

c2pa-python

serializationpythonv0.32.6

harness data pending

Install & Compatibility

Where this runs

No compatibility data collected yet for this library.

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

Reader

✓ from c2pa import Reader

core class for reading C2PA manifests

SignerInfo

✓ from c2pa import SignerInfo

used to configure signing (keys and certs)

Builder

✓ from c2pa import Builder

used to create and sign manifests

Verify C2PA manifest from file, then create and sign a new manifest using environment variables for credentials.

import os from c2pa import Reader, Builder, SignerInfo # Verify an image's C2PA manifest reader = Reader.from_file('test_image.jpg') print(reader.json()) # Sign an image signer = SignerInfo.from_settings({ 'alg': 'es256', 'private_key': os.environ.get('C2PA_PRIVATE_KEY', ''), 'sign_cert': os.environ.get('C2PA_SIGN_CERT', '') }) builder = Builder(signer) manifest = {'claim_generator': 'my_app/1.0'} output = builder.sign('input.jpg', 'output.jpg', manifest) print(output)

Debug

Known issues

breakingThe `SignerInfo` API changed in v0.30.0: old `from_certs` removed, use `from_settings` with `private_key` and `sign_cert` keys.

fix

Use `SignerInfo.from_settings({'alg': 'es256', 'private_key': '...', 'sign_cert': '...'})`.

affects: <0.30.0

deprecated`Reader.from_buffer` is deprecated in v0.32.0; use `Reader.from_bytes` instead.

fix

Replace `Reader.from_buffer(data)` with `Reader.from_bytes(data)`.

affects: >=0.32.0

gotchaThe `Builder` requires the full chain of intermediate CA certificates in `sign_cert`; missing intermediates causes a validation error on verification.

fix

Include the full certificate chain in the `sign_cert` value (PEM).

affects: all

Errors

Common errors & fixes

c2pa.ValidationException: InvalidSignature

The signer certificate chain is incomplete or the private key does not match the certificate.

fix

Provide the full cert chain in `sign_cert` and ensure the private key matches the leaf certificate.

ModuleNotFoundError: No module named 'c2pa'

The c2pa-python package is not installed or installed in a different environment.

fix

Run `pip install c2pa-python` and verify Python version >=3.10.

TypeError: from_file() missing required positional argument: 'path'

Using `Reader.from_file` without a path string, or passing a file object.

fix

Use `Reader.from_file('image.jpg')` with a string file path.

Upgrade

Version history

0.32.6latest on PyPI · released May 1, 2026

Audit

Dependencies

No dependency data recorded yet.

Agent activity

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Resources

githubhttps://github.com/contentauth/c2pa-python ↗

packagehttps://pypi.org/project/c2pa-python/ ↗

homepagehttps://contentauthenticity.org ↗