How to view the change history of a Fast Line Pro agent and roll back a version?

The agent editor has a History button. It lists every save of the agent settings: who, when and from where made it. For each version you can see what changed, compare it with the current agent, view and copy the instructions and variables, and restore the version if needed.

When you need it

• The agent prompt changed and you need to know who changed it and when.
• The agent answers worse after a change and you need the previous instructions or model back.
• You need a piece of an old prompt without rolling the agent back.

Important to know

• The history is recorded since the platform update. Earlier changes do not appear in it.
• Versions are kept for 180 days, then removed automatically.
• The history works when the settings change log (Settings Audit Trail) is enabled on the instance. When it is off, there is no History button.
• Restored: instructions, variables, model (with its parameters), connected knowledge bases together with their search settings (number of results, threshold, reranking) and image/file upload.
• Not restored: agent tools (built-in, MCP, scenario MCP Tool sections) and service settings not shown in the editor. They stay as they are now. Tool changes are visible in the history and in View.
• The source of a version is for reference:
  • UI — a save from the Constructor panel. External integrations that send requests with the X-CSRF-TOKEN header are labelled the same way.
  • API — a request with a token in the Authorization: Bearer header. Instance Agent working without delegation (with a regular login token) is recorded as API too.
  • Instance Agent — a change Instance Agent made on behalf of a user.
  • MCP — a request with an MCP key.
  • System — a change without a user: applying a Marketplace package, the AI QA checklist sync, a scenario binding. Such records have no author: “System · AI QA checklist” does not mean the person who saved the checklist.
• Edits made bypassing the panel (directly in the agent backend) are not recorded. They appear as part of the next publication and look like a change by whoever published it.
• A version is written right after the publication, in the background. If the platform restarts at that very moment, the record may be lost.
• A rollback publishes the agent immediately: it starts answering with the restored version, including in ongoing conversations.

Before you start

• To see the history — the Fast Line Pro view right (Fast Line → view).
• To restore versions — also the save right (Fast Line → save).
• The agent is opened in the new Fast Line Pro interface: Menu → Fast Line Pro → Agents → agent.

How to view the history

1. Open the agent: Fast Line Pro → Agents → the agent.
2. Click History next to the agent name.
3. The Agent settings tab lists the versions, newest first. Each row shows the date and time, the author and the source. A rollback has the line “Rollback to version from …”.
4. Click Show more to load earlier versions (20 at a time).

The oldest record may have the item State before the first recorded change — the agent settings as they were before the first save after the platform update.

What you can do with a version

The value *** is hidden (for example, an access key). It is not compared and does not count as a change.

If the previous state of a version was not recorded (for example, the first save of a new agent), What changed shows “The previous state was not recorded” and the version itself.

How to restore a version

1. In the version row, click Restore this version.
2. In the confirmation window, review the difference with the current agent and the warnings:
   • how many changes were made after this version and by whom — they will be overwritten;
   • Tools are not rolled back — when the version had a different set of tools;
   • the agent is managed by an AI QA checklist or modified by Instance Agent — they may overwrite the rollback;
   • a knowledge base of the version was deleted or is unavailable — it will not be connected;
   • the model of the version is no longer available — the current one is kept;
   • unsaved changes in the editor will be lost.
3. Click Restore.

After the rollback you see “Version restored and published”, the editor reloads the agent, and the history gets a new row “Rollback to version from …”. A rollback can be rolled back too.

Knowledge base change history

The same History window has a second tab — Knowledge base. It shows who added, edited, enabled or disabled, or deleted documents and chunks of the knowledge bases currently connected to the agent, when and from where.

Each row shows:

• date and time, author and source — the same labels as for agent versions (UI, API, Instance Agent, MCP, System);
• the action: “Document added”, “Document renamed”, “Document enabled”, “Document disabled”, “Document deleted”, “Chunk added”, “Chunk edited”, “Chunk enabled”, “Chunk disabled”, “Chunk deleted”, “Chunks uploaded: N new, M updated”, “File import: N applied”;
• the knowledge base and the document. Chunks written via API or MCP (for example, by Instance Agent) go to a service document — the row calls it Chunks from API/MCP, its technical name is shown in the hover hint;
• up to 5 chunk or document IDs and “and N more”, plus the count.

Important to know:

• Chunk text is not stored and is not shown. A chunk or document cannot be restored from the history — you only see who changed what.
• Only knowledge bases currently connected to the agent are shown. If you disconnect a knowledge base, its rows disappear from the tab but stay in the settings change log (types Fastline Pro knowledge base documents and Fastline Pro knowledge base chunks).
• A chunk import from a file is recorded as one row “File import: N applied” — without an author, with the System source.
• Not recorded: applying a Marketplace package and edits made bypassing the panel.
• If enabling chunks ended with an error (for example, a chunk was not indexed), that change may be missing from the history.
• The knowledge base history is also recorded since the platform update and kept for 180 days.

Where else to look

All changes of one knowledge base are also shown on the page of the knowledge base itself: Knowledge bases → the knowledge base you need → the History button above the document list. The Knowledge base change history window shows the same rows as the agent tab, but for the whole knowledge base — including when it is not connected to any agent or was disconnected. There is no filter by document here.

How to check that it works

• Change a line in the instructions and click Publish → History shows a new top row with your name and the UI source.
• What changed for that row shows only the changed instruction line, the other sections are “No changes”.
• The settings change log has a Fast Line Pro agent settings record with the link “See the agent history for details”.
• Edit a chunk of a connected knowledge base → History → Knowledge base: the top row is “Chunk edited” with your name, the UI source, the chunk ID and “1 chunk”.

Common situations

Related materials

• Configure the agent prompt
• Connect and configure agent tools
• Connect a knowledge base to the agent
• View the settings change log