Ledger integrity

What makes the record evidence, not just a log

Most tools keep an activity history that an admin can edit or purge. Arc-Tec keeps one append-only chain per workspace. Nothing in the product can update or delete an entry, and the chain makes any gap or edit detectable.

Each event carries

seq

A gapless sequence number within the workspace. Missing numbers mean missing events.

prevHash

The hash of the event before it. Editing any earlier event changes every hash after it.

hash

SHA-256 over the workspace, sequence, kind, actor, subject, full payload, prevHash, and timestamp, serialized with sorted keys.

payload

The full before and after of what changed. A blueprint edit stores both versions, not a count.

Verifying

1. Open the Ledger tab. The header shows the live verification result: chain intact with the event count, or the first broken sequence number.
2. Export the ledger. Every row carries its seq, prevHash, and hash, so an auditor can recompute the chain outside Arc-Tec.
3. Daily anchors record the chain head. Business plans email the anchor to the workspace owner, giving an independent copy of the hash.

What it does not claim

A hash chain proves the record was not altered after the fact. It does not prove a person told the truth when they wrote an entry. That is why every event names its actor and why approvals require the approver's own account.

Accounts and access

Sign-in is handled by Clerk with Google, GitHub, or email. Every backend function checks workspace membership before reading or writing. Roles carry a rank: only owners and leads invite or remove, nobody removes someone of equal or higher rank except the owner, and every membership change is itself a ledger event.