Prove your agent stayed inside the rules.

In one signed bundle.

The regulator asks "did you send customer PII to OpenAI in July?" and you have to answer with more than trust. Etch produces a hybrid-signed JSON evidence bundle that verifies offline against your operator's pinned public keys. No screenshots. No log grep. No "trust us."

Read the compliance mapping → Start a pilot

The one-command answer to a regulator's question

curl -sSL -X POST \
  https://etch.systems/evidence/YOUR_PROJECT \
  -H "Content-Type: application/json" \
  -d '{"kind":"no_tool_call",
       "tool_name":"openai:chat/completions",
       "period_start":"2026-07-01T00:00:00Z",
       "period_end":"2026-08-01T00:00:00Z"}' \
  > openai-usage-evidence.json

etch-verify --evidence openai-usage-evidence.json \
            --public-keys ./trusted-keys.pem
# Expected: verdict=confirmed  epochs verified  signature envelope verified

Three claim shapes today, all signed the same way:

no_tool_call

"We never called OpenAI's chat/completions API in Q3." Verified against the audit chain, signed, returned in JSON.

no_events_matching

"No event's tool_input carried the string customer_ssn during the reporting window." LIKE-style substring; four allowlisted fields.

tool_call_count

"The agent called Bash exactly 42 times." Exact-count assertions for audits that need "how many" not just "whether."

Signed monthly statements

Every project ships a signed audit statement for any past month in three formats derived from one canonical payload:

HTML for the browser and Print-to-PDF
Signed JSON for automated verifiers and diff-against-last-month
PDF for the compliance folder your regulator drops files into

Every statement carries the Merkle roots of the first and last epochs in the period, so an auditor can prove the statement covers every signed batch in the window. The key_generation_id field lets a downstream verifier detect an unexpected mid-period key rotation before the fingerprint change bubbles up.

Framework mapping

The compliance-mapping doc cites specific clauses in four named frameworks and the exact Etch feature that satisfies each:

EU AI Act (Regulation 2024/1689) — Articles 12, 15, 26-27, 72, 79
SEC 17a-4 — the 2022 audit-trail-alternative path
NIST AI RMF 1.0 — Govern / Map / Measure / Manage
FIPS 186-5 (Ed25519), FIPS 205 (SLH-DSA-SHA2-128f, post-quantum), FIPS 180-4 (SHA-256)

Includes a "what compliance officers should ask us" Q&A section answering every question we have been asked to date.

Substrate trust, not sales trust

Hybrid post-quantum signatures

Every epoch envelope carries both a classical Ed25519 signature (FIPS 186-5) and a post-quantum SLH-DSA-SHA2-128f signature (FIPS 205). A verifier rejects the envelope unless BOTH verify. A compromise of either algorithm alone does not break integrity.

13-attack adversarial suite

Every plausible tamper an insider with disk access could attempt — bit flip, row rewrite, entry delete, forged signature, rollback, split view, key substitution — is a code- testable property with an anchoring test. Read the analysis.

Offline verifier

etch-verify runs on any machine with the pinned public keys. No network access to Etch required after the auditor downloads the bundle. Compliance conversations that would otherwise require the operator's continued cooperation now do not.

Ready to try it against a live claim?

Sign up, pick a starting project, POST an evidence claim in JSON, verify the signed response offline. If you want a walkthrough with the founder, reply to your signup confirmation email — typically a 20-minute call.