Route timestamps through your own TSA (BYOT)

Sigill's managed pool — multiple independent commercial TSAs with automatic failover — is the right default for almost everyone. But some organisations don't get to choose: a regulator mandates a national authority, a contract names a specific provider, or an internal TSA already anchors the company's evidence chain. Bring-your-own-TSA makes that a routing decision instead of a platform migration.

Register and verify

Add the endpoint under Settings → Timestamp Authorities, with whatever authentication your authority requires on outbound requests. Before it can be used, Sigill verifies the endpoint technically: it must speak RFC 3161 correctly and return well-formed tokens. Unverified entries can be saved but never used for stamping — a misconfigured endpoint fails at registration time, not in your production pipeline at 2am.

One honest boundary, stated the way our docs state it: Sigill verifies technical RFC 3161 compatibility — not your commercial right to use the endpoint. The relationship with the authority is yours.

Use it

Point tsaSlug at your reference — everything else about the request is unchanged:

curl -s -X POST https://api.sigill.ai/tsa/stamp-hash \
  -H "Authorization: Bearer $SIGILL_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"hashHex":"'$HASH'","tsaSlug":"byot:corp-tsa","label":"quarterly-report"}'

The hash-only privacy model, the .tsr artifact, dashboard history, and independent verification all work identically — the token simply carries your authority's signature instead of one from the managed pool. BYOT references are tenant-private: your endpoints are yours alone, invisible to other tenants.

What BYOT deliberately doesn't change

• Qualified timestamps still route through eIDAS-qualified providers validated against the EU trust list — qualification is a property of the authority, not of routing (details).
• tsaSlug: "auto" remains the managed pool with rotation and failover — a single customer endpoint has no failover partner, which is the trade you're explicitly choosing.
• Verification of a BYOT-issued token needs your authority's CA bundle, like any RFC 3161 token — worth archiving alongside the tokens if the authority is internal.

Where this lands in practice

Mandated national or sector authorities; enterprises with an internal TSA that must anchor all corporate evidence; and migrations — organisations that adopted Sigill for the workflow but need continuity with an existing timestamping relationship. The BYOT launch post walks through a full registration and verification.