The KWAM SDK
A pip-installable, self-contained API that erasure-codes bytes into signed, content-addressed fragments and rebuilds them fail-closed. Any k of n fragments rebuild the exact original — or recovery raises. KWAM.CH itself is built on it: every Python asset is protected by RS(8,4) and SHA-256 verified at build.
protect turns bytes into signed fragments; recover rebuilds them or refuses. Deterministic codecs produce every byte; SHA-256 gates each one.
# Erasure-code any bytes into 12 signed, content-addressed fragments.
from kwam import protect, recover
obj = protect(data, k=8, m=4) # n = k + m = 12 fragments
obj.obj_cid # 'sha256:<hex>' — the whole-object content id
obj.frag_cids # 12 per-fragment content ids, index-bound
obj.scheme # 'reed_solomon(8,4)'
obj.millibit # 1500
obj.manifest # JSON — round-trips, rides in signed metadataFail-closed by default recover verifies each fragment against its index-bound frag_cid, requires ≥ k verified fragments, then re-hashes the whole object. The index-binding defeats relabel-and-invert attacks. It never returns the wrong bytes silently; it raises.
Hand recover the surviving fragments and the manifest. If enough verify, you get the original bytes back, re-hashed. If not, it raises rather than guess.
# Survivors can be any k of the n fragments — order need not matter.
from kwam import recover
original = recover(surviving_fragments, manifest)
assert original == data # exact bytes, re-hashed against obj_cid# Fail-closed: too few survivors, or a tampered fragment, and it refuses.
from kwam import recover, ResilienceError
try:
data = recover(too_few_or_tampered, manifest)
except ResilienceError as err:
# Below k verified survivors — the data is gone, and KWAM says so.
log.error("recovery shortfall: %s", err)
raise # never a silent wrong-bytes returnWhen the data is gone, we say so Below k verified survivors, the original cannot be rebuilt. KWAM reports that shortfall; it never fabricates the missing bytes. Durability is six nines (99.9999%), a design target; the defensible guarantee is no silently-corrupted bits. Knowing a byte is lost is not the same as recovering it, and we never pretend otherwise.
Small surface, deterministic behaviour. The bytes come from the codec; the gates come from SHA-256.
| Symbol | Signature / shape | Behaviour |
|---|---|---|
| protect | protect(data, k=8, m=4) -> ProtectedObject | Erasure-codes data into n = 12 signed, content-addressed fragments. |
| ProtectedObject | .obj_cid · .frag_cids · .scheme · .millibit · .manifest | scheme = reed_solomon(8,4), millibit = 1500, manifest is round-tripping JSON. |
| recover | recover(fragments, manifest) -> bytes | Any k of n verified fragments rebuild the exact original; fail-closed and SHA-gated, raises ResilienceError on shortfall or tamper. |
| durability_target | durability_target(...) -> dict | Returns the durability math tagged 'kind':'DESIGN_TARGET', never a promise. |
| ContentId | ContentId(...) | Wraps the prefixed sha256:<hex> string. |
| KwamBit | .from_recovery() · recover_bit() · .verify() | A SHA-gated immutable wrapper, built only via recovery; verify() raises BitIntegrityError if the bit does not match. |
Run on the pure-stdlib floor, or add numpy for speed. The contract is identical; only the throughput differs.
Pure standard library, no compiled dependencies. Always available, including in CI.
pip install kwamAdds numpy for a faster codec path. Same fragments, same SHA gates, same fail-closed recovery.
pip install kwam[numpy]In production The manifest rides in cosign-signed metadata, so the recovery path can trust the scheme and the fragment ids it is handed. The codec produces the bytes; the signature and SHA gates decide whether to trust them.
Every Python asset behind this site is erasure-coded by the same protect / recover you would call.
The SDK is proprietary and licensed directly. Tell us about your workload and we'll scope access.
KWAM is our intellectual property, grounded in Swiss law.
KWAM — its source code, the KWAM language, the JHMM reconstruction orchestrator, the deterministic codec runtime, and all associated AI components — is a proprietary computer program and the sole and exclusive intellectual property of KWAM.CH. As a computer program it is a protected work under the Swiss Federal Act on Copyright and Related Rights (Copyright Act, CopA), and the exclusive rights of use vest in KWAM as employer; it is further protected as a trade secret under the Swiss Federal Act Against Unfair Competition (UCA). KWAM is offered by private licence only. All rights reserved.
CopA (SR 231.1) Art. 2 para. 3 & Art. 17 · UCA (SR 241) Art. 6 · Governed by the laws of Switzerland · Place of jurisdiction: Zürich