What goes in an audit log?
- Actor — who took the action: a teammate, an API key, a scheduled job, or an AI agent working through an API or an MCP server.
- Action — what they did: sent a campaign, changed a consent record, edited a segment rule, paused an ad audience.
- Target — the resource affected, with a stable identifier: which journey, which template, which profile.
- Timestamp — when it happened, to the second, in a fixed timezone; UTC keeps entries comparable.
- Context — the why, where you have it: the before-and-after values, the reason given, the request that triggered it.
How does an audit log work?
Every meaningful action writes one row and moves on — the log is never updated in place. That append-only design is what makes the history trustworthy: you can replay exactly what happened, in order. But append-only in the application is not the same as tamper-evident. If someone with database access can rewrite rows, the log proves less than it looks like it does. Making it tamper-evident — write-once storage, hash-chaining, or shipping entries to a separate system — is a further step, and engineering standards such as NIST's guide to log management treat protecting log integrity as its own requirement.
How do you audit an AI agent's decisions?
When an AI agent changes things in your tools, through an MCP server or a built-in assistant, the audit log is how you keep human-in-the-loop oversight after the fact. Each action (a segment created, a journey drafted, a change approved) should be recorded with the agent or key that made it, the person who approved it where there was an approval, and the inputs it used. fromHello records MCP tool calls in the workspace audit log: the tool, who called it, when, and whether it succeeded. That gives you a trail you can read and question, instead of a black box.
Why it matters for a two-person team
The GDPR's accountability principle says you must be able to demonstrate compliance, not just claim it — and regulators such as the UK's ICO point to records of what you did as the evidence. An audit log is that evidence, produced as a side effect of normal use rather than assembled in a hurry before a review. If you self-host, it lives in your own database; the practical setup is covered in GDPR and self-hosting, while this entry only defines the log.