several ai agents. one governance layer. every run provable.

bernstein is the open-source governance layer for ai agents: a deterministic python scheduler runs them in parallel, with no model in the coordination loop, so a plan replays to the same task graph. it runs on policy as code: you write the policy, bernstein enforces it, and produces the verifiable record.

ask anything.

one run, four stages.

evidence, not vibes

every step signed, in order, on disk.

run with --audit and bernstein writes an hmac-chained event log under .sdd/audit/, one jsonl file per utc day. each entry references the previous hash. tampering breaks verification. nothing leaves your machine.

someone who did not run it can check it. signature and hash-chain checks read the files alone; the hmac leg needs the key the chain was written with, so hand a reviewer both and bernstein audit verify answers without rerunning anything. not a screenshot, not a SOC2 PDF - a hash chain that recomputes.

configure a signing key and a run also writes an ed25519-signed receipt binding the journal and lineage heads. bernstein verify receipt reads that file alone - no hmac key, no .sdd/. pin the public key for provenance. no key, no receipt.

# reading .sdd/audit/2026-07-24.jsonl · 412 entries · 18m04s span

17:42:01  manager.plan     cb84a1…  13 tasks · est $4.20
17:42:18  scheduler.spawn  3e09f7…  t-001 → backend (sonnet)
17:42:18  scheduler.spawn  81c2dd…  t-002 → backend (sonnet)
17:42:19  scheduler.spawn  b50af8…  t-003 → qa      (opus)
17:55:11  janitor.verify   d014a3…  t-005 docs · pytest 84/84 · ruff 0
17:55:14  manager.merge    ee7c12…  t-005 → main · 4 files · clean
18:02:14  janitor.fail     9aa10b…  t-003 qa · pytest collect err · 3/3 retries
18:02:30  scheduler.route  71b4cc…  t-003 opus → sonnet · awaiting op
18:09:14  scheduler.pause  4d2e09…  conflict · t-001 ↔ t-007 · src/auth/refresh.py

verify chain      ok ✓  412/412 entries · last hash 4d2e09cb…
hmac key          ~/.local/state/bernstein/audit.key