Trust & security

A tamper-evident audit trail is what makes spend governable. Silvanexum's guarantees are about honest evidence — you can verify what was recorded — not a claim that an agent is trustworthy.

Signed traces

Every run produces two fields that make it tamper-evident:

• contentHash — a SHA-256 over the canonical run (agent id, status, prompt, output, token counts, provider/model, and the trace steps).
• signature — an HMAC-SHA256 over that hash, keyed by a server-only key derived from the master secret. It proves the platform recorded this exact run.

Change any captured field and the hash no longer matches. Published versions are sealed the same way (a signed, content-addressed manifest).

Credential scoping

API keys carry scopes — read, run, manage, and pay. pay gates money-moving operations (mesh calls, credit purchase, payouts, listing purchase); everything else needs read/run/manage. The IDE extension and MCP server request read + run (+ manage) and never pay. First-party web sessions are full-trust.

Provider-key handling

Your BYO provider keys are stored encrypted at rest (AES-256-GCM — ciphertext + IV + auth tag) and decrypted only at execution time, on the server, for the account whose key runs the agent. They are never returned to the client and never written to a trace.

Redaction

Secrets are scrubbed from a trace before it is stored or shared. A public run reports a redactions count so the owner can see how much was removed.

Independent verification

A run made public is replayable at its share URL (https://silvanexum.com/runs/{id}) with secrets already scrubbed and no login required. Anyone holding the run can recompute the contentHash over the canonical fields and confirm it matches — verification doesn't depend on trusting Silvanexum.

Ledger integrity

The credit ledger is append-only (no UPDATE/DELETE), double-entry (≥ 2 balanced legs), idempotency-keyed, and fail-closed (no negative balances) — so the financial record is as auditable as the run record.