An agent that drives a paid tool in the browser, with thirteen safety rules
Internal tooling
Some tools have no API, so Prospicience built an agent that operates one the way a person does, inside a real logged-in browser session. Thirteen non-negotiable rules govern every action: one tab, submit exactly once, never retry blind, never regenerate without approval, and nothing downloaded or assembled until a person signs off.
- non-negotiable rules
- 13
- browser tabs allowed
- 1
- submissions per job
- exactly 1
- regeneration without approval
- never
- 01
Built an agent that operates a video generation tool through...
- 02
Wrote thirteen non-negotiable rules covering every action it...
- 03
Shipped a written operating procedure and directing templates
- 04
Assembles finished shots into a cut, only after a person...
Submit exactly once, and never treat an unchanged page as a failed submission. That single rule removes the most expensive failure in browser automation: paying twice for one job. Every retry waits and inspects first, and no new work or regeneration starts without explicit approval.
The challenge
Driving a paid generation tool through the browser risks double submissions, blind retries and accidental regenerations, and each of those spends real money in someone else's account.
Why it mattered
Browser tools often look idle while they work, and an agent that reads a quiet page as a failure clicks again and pays twice. On a credit-billed account, a few blind retries can drain a budget and clutter someone else's workspace before anyone notices.
What we built
- Built an agent that operates a video generation tool through the user's existing logged-in browser session.
- Wrote thirteen non-negotiable rules covering every action it can take, from tab handling to downloads.
- Shipped a written operating procedure and directing templates, so behaviour is defined, not improvised.
- Assembles finished shots into a cut, only after a person approves the final clips.
The result
- Productions run on a tool with no API, with exactly one submission per approved job.
- Every extra spend, whether a retry, a regeneration or a variant, needs an explicit yes first.
- Feedback is applied only to the named clip, so approved shots stay untouched.
- The test production came out as two assembled versions of a short film, built from approved clips only.
Built for trust
Submit exactly once, and never treat an unchanged page as a failed submission. That single rule removes the most expensive failure in browser automation: paying twice for one job. Every retry waits and inspects first, and no new work or regeneration starts without explicit approval.
AI at work
AI operates a paid video tool that has no API, the way a person would: it submits the approved job once, waits while it renders, reviews each clip and reports back. It asks before spending a single extra credit.
What it produces
- One submission per approved job
- Shot by shot review summaries
- A written log of every requested change
- Assembled cuts from approved clips
How it works, day to day
A person approves the prompt. The agent submits it once, waits patiently while the tool renders, then summarises each clip for review. Any change that costs credits waits for a yes, and only the final approved clips are downloaded and assembled into the cut.
Where it saves time, and gets better with use
- The team gets productions from a tool built only for people, without sitting at the screen through every render.
- Feedback is applied only to the named clip, so approved shots stay untouched and nothing is paid for twice.
- Each round's changes are logged by clip, so the next round starts from what is already approved.
By the numbers
- 13
- non-negotiable rules
- 1
- browser tabs allowed
- exactly 1
- submissions per job
- never
- regeneration without approval
- 8
- shots in the assembled test film
The technology
- Works a tool that has no API, the way a person would
- Thirteen rules it is not allowed to break
- Submits once, then waits and looks before doing anything else
- Never starts new paid work without being asked
- Claude (Anthropic)
Technical notes
- Single tab, single canonical workspace, enforced as an invariant rather than a convention
- Submit exactly once, with an unchanged page explicitly defined as not a failure signal
- Mandatory wait and inspect before any retry decision
- Final assembly gated behind explicit user approval
- Operating procedure and directing templates shipped alongside the agent as reference documents
Questions we get asked
- What is the biggest risk in browser automation?
- Double submission. The agent clicks, the interface does not visibly change within a second, and a naive agent clicks again. On a paid tool that is a duplicate charge, which is why our agent is built to submit once and then wait and look.
- Why not just use the tool's API?
- Because this one has none. Where an API exists we use it, since it is faster and more reliable. Browser driving is how we reach capability that is only available through an interface built for people.
- Can the agent spend money without asking?
- No. No new work and no regeneration starts without explicit approval, and final assembly waits for a person. The account owner stays in control of every credit.
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Built in a day