BLACKBOX seals every reasoning step, tool call, and output your AI agent makes into a cryptographic hash chain. Any post-hoc alteration breaks the chain — detectably, permanently, and without requiring you to trust us.
hash = sha256(prev_hash + canonical_json(event))Every event commits to all prior events. Alter anything — a single byte of a system prompt, a reasoning step, a token count — and every downstream hash changes. The chain breaks at that point. Verifiable in O(n) with stdlib sha256 only. No BLACKBOX infrastructure required.
POST /v1/events or uses the SDK. The server assigns sequence, computes prev_hash, and seals the event. Append-only — there is no UPDATE or DELETE path for events. Ever.hash = sha256(prev_hash + canonical_json(event_without_hash)). Genesis uses prev_hash = "GENESIS". Each event's hash is a commitment to every event that came before it. One tampered byte — the chain breaks from that point forward.GET /v1/audit/{run_id} returns a public certificate — no auth, share with any auditor or regulator. Chain validity is recomputed on read. No stored result to falsify. The math is the guarantee.import blackbox_sdk as bb
bb.configure(api_url="https://blackbox-gold.vercel.app")
with bb.run(
"agent_001",
model="claude-sonnet-4-6",
system_prompt=SYSTEM_PROMPT,
tools=["web_search", "calculator"],
sampling={"temperature": 0.3},
) as run:
run.reasoning("Planning next step")
run.tool_call("web_search",
inputs={"query": "Q3 revenue"}, result=hits)
run.output(
"The Q3 revenue was $4.2M",
tokens_in=520, tokens_out=180,
cost_usd=0.0042, latency_ms=1340,
)
# ↑ Sealed automatically. Chain is provable.run.reasoning(), run.tool_call(), run.output().bb.instrument() patches openai + anthropic at startup. Zero agent code changes — every LLM call is auto-recorded.Install the SDK, record your first run, and produce a cryptographic audit certificate — in the time it takes to read this page.
pip install blackbox-sdk — zero external dependencies, stdlib urllib only.bb.configure(api_url="..."). No API key needed to start.GET /v1/audit/{run_id} returns a public certificate. Recompute with stdlib sha256 to prove it.sha256 and canonical JSON. Zero BLACKBOX infrastructure. One Python function, 12 lines, stdlib only./v1/audit/{run_id} — no auth, share with any auditor. Chain validity computed fresh on every request. No cached result to falsify.You need a record that proves what happened — and proves it hasn't been altered. Not a log. A chain.