What a tamper-evident audit trail actually means
Why an audit trail matters for AI agents
When an AI agent acts on your behalf — downloading a file, submitting a form, sending a message — you have a right to know exactly what it did and in what order. This is true for practical reasons (did it actually complete the task correctly?) and for accountability reasons (if something went wrong, what happened?). Without a reliable audit record, you are taking the agent's word for it.
The word of an AI system is not a reliable audit record. A reliable record is one that is complete, tamper-evident, and produced independently of the system being audited.
How hash-chaining works
BackBrain's audit ledger uses the same principle as blockchain integrity checks: each entry contains a cryptographic hash of the previous entry. This creates a chain where altering any record requires recomputing all the hashes that follow it — a modification that is computationally detectable.
In practice this means: if a record is deleted, edited, or inserted after the fact, the chain integrity check fails and the tampering is detected. The ledger is stored locally on your device, so no external party can alter it — and BackBrain itself cannot quietly edit past entries without the modification being visible.
Run transcripts: the plain-language record
Alongside the audit ledger, every BackBrain run produces a searchable transcript written in plain language. The transcript records what the agent observed on each screen, what it decided to do and why, what it actually executed, and what the result was — including whether a step was verified successful before moving on.
Transcripts are redacted before storage: sensitive values entered during the run — passwords, OTP codes, account numbers — are replaced with placeholders. The sequence and outcomes are preserved; the secrets are not.
What is and is not recorded
- Recorded: every action taken and its observed outcome, approval prompts shown and responses given, steps verified successful, steps that failed and how they were retried, the AI reasoning summary for each decision.
- Not recorded: passwords, OTP codes, card numbers, account numbers, or the contents of fields marked as sensitive. Credential screens are never captured or logged.
Searching past runs
BackBrain's History panel is a full-text search over all your past run transcripts. You can search by task description, by date range, by the name of a website or app involved, or by the outcome (completed, interrupted, failed). The result shows the matching run with the exact sequence of steps taken.
This is useful for confirming a task completed correctly ("did it actually send the file?"), for understanding what went wrong in a failed run, and for finding the right run to teach from or correct.
Who can see the audit record?
Only you. The audit ledger and transcripts are stored on your device and are not synced to any cloud server. BackBrain cannot read your audit records remotely. If you export a transcript to share with an accountant or for your own records, that export is a copy you control — the original stays local and you decide what to share.
The audit trail records the output of BackBrain's three autonomy tiers in action — every approval prompt shown, every Tier-3 confirmation typed, and every blocked action are permanent entries in the hash-chained ledger.
Get BackBrain to do this for you
BackBrain is in free private beta for Windows and Android. Reserve early access.
Reserve Early Access — hello@backbrain.inFrequently asked questions
Can BackBrain edit or delete its own audit records?
No. The hash-chained ledger is designed so that any modification — including deletion — breaks the chain integrity check and is detectable. BackBrain cannot silently alter past records.
Are my passwords stored in the audit log?
No. The transcript records that a password was entered and that the login succeeded, but not what the password was. Sensitive fields are replaced with placeholders before storage.
How far back do audit records go?
By default, BackBrain retains all run transcripts on your device until you choose to delete them. You control retention and can export, archive, or delete records at any time.