Public sandbox · live · stateless

Seal a fact.
Right now.

Type any sentence. We produce a real Sealed Evidence Record and anchor it to the public Sigstore Rekor transparency log. Click the verify link to confirm it independently — no install, no account, no Verdict tenant required.

This page uses the same canonical-record + Sigstore code path as the productionverdict_create_evidence_recordMCP tool. The signing key tier is the only difference.

Surface tier disclosure

Public sandbox: ephemeralECDSA P-256 / SHA-256keypair generated per Vercel serverless instance. Production tenants: Ed25519 bound to FIPS 140-2 Level 3 HSMs. The Sealed Evidence Record format and Sigstore Rekor anchoring are identical across both tiers — only the signer changes. Full disclosure at /security and /dpa.

191 / 2048 bytesECDSA P-256 / SHA-256 · ephemeral · public sandbox tier
Now do it from your code

The same call, from Claude.

The browser button above is a thin wrapper around the same MCP tool Claude calls. Install the connector and the next time Claude produces a legal output, it can seal it the same way.

# Remote endpoint (live Sigstore Rekor anchoring on every record)
claude mcp add verdict --transport http --url https://verdict.systems/api/mcp

# Local stdio (offline-capable; no transparency-log anchoring)
claude mcp add verdict-local -- npx -y @verdict-systems/mcp

Full install guide for Claude Code, Claude Cowork, and claude.ai →