Install & Compatibility
Where this runs
tested against v4.0.2.8 · pip install
no network on importno background threads
Install × environment matrix
Each cell = how many times install + import succeeded across repeated harness runs. Partial = flaky.
glibc = Debian/Ubuntu slim · musl = Alpine Linux
py 3.10
✕ build_error
✕ build_error
py 3.11
✕ build_error
✓ 1.5s
py 3.12
✕ build_error
✓ 1.5s
py 3.13
✕ build_error
✓ 1.5s
py 3.9
✕ build_error
✓ 1.8s
17MB installed
● package 17MB
Code
Verified usage
Verified import paths — ran on the pinned version, not inferred.
pymonocypher
✓ from pymonocypher import pymonocypher as m
✗ import pymonocypher
The main module is nested; direct import misses the bindings.
crypto_sign
✓ m.crypto_sign(msg, sk)
✗ pymonocypher.crypto_sign(msg, sk)
Must use the imported module alias after correct import.
Generate a signing keypair, sign a message, and verify the signature.
from pymonocypher import pymonocypher as m
key = m.crypto_sign_keypair()
print('Public key:', key.pk.hex())
msg = b'Hello'
sig = m.crypto_sign(msg, key.sk)
print('Signature:', sig.hex())
# Verify
m.crypto_sign_verify(sig, msg, key.pk)
print('Verified OK')
Debug
Known issues
breakingUpgraded from Monocypher 3.1.3 to 4.0.2 in v4.0.2.1; incremental SignatureVerify removed.fixUse crypto_sign_verify instead of IncrementalSignatureVerify.
affects: >=4.0.2.1
breakingcompute_signing_public_key now requires a 64-byte secret key (full keypair output). The 32-byte variant is deprecated as of v4.0.2.3.fixPass the full 64-byte secret key (sk) to compute_signing_public_key. For the deprecated 32-byte variant, update your code to use the full key.
affects: >=4.0.2.3
deprecatedcompute_signing_public_key 32-byte variant deprecated in v4.0.2.3 and will be removed in a future release.fixUse the 64-byte secret key variant.
affects: >=4.0.2.3
gotchaargon2i_32 had incorrect parameter nb_block (should be nb_blocks) fixed in v4.0.2.4.fixUse nb_blocks instead of nb_block when calling argon2i_32.
affects: <4.0.2.4
gotchaPython 3.10 support dropped as of v4.0.2.6/v3.1.3.5.fixUse Python >=3.11 or pin to an older version (v4.0.2.5 supports 3.10).
affects: >=4.0.2.6, >=3.1.3.5
Upgrade
Version history
4.0.2.8latest on PyPI · released Jun 1, 2026
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Dependencies
No dependency data recorded yet.