Why Synthetic Data Is the Real Bottleneck for Computer Use Agents
Everyone talks about compute budgets and model size. But behind every cutting-edge computer use agent is a quiet bottleneck: data. Real-world interaction data is fragmented, expensive, and risky. Synthetic data isn't just a convenience. It's the lever that makes agents actually usable.
The real cost of real data
Capturing desktop trajectories requires live environments, consented users, and careful logging. A 2024 study of agent training datasets found that only 4% of real-world interaction logs met basic quality standards: complete trajectories, clear intent, and safe execution. The rest were noisy, truncated, or unsafe. Cleaning and annotating that data can cost 10x more than the raw collection. And it still carries legal and privacy risk.
Synthetic trajectories close the gaps
Synthetic data solves three problems at once: coverage, safety, and cost. Synthetic trajectories can include rare edge cases, like unexpected error dialogs, popup windows, or multi-step workflows, that rarely appear in real logs. A recent evaluation of agent policies trained on synthetic vs. real data showed that synthetic trajectories reduced failure rates on custom tasks by 27% while cutting per-example labeling cost by 60%. The key is not just generation. It's fidelity to real interaction patterns.
Generation methods that matter
- ●Computer use agents running on real desktops and browsers produce high-fidelity trajectories, including mouse movements, clicks, keystrokes, and browser events.
- ●Programmatic simulation can generate structured workflows but often misses context like UI layout, timing, and error states.
- ●Hybrid approaches blend real behavior captured during agent testing with programmatic generation to improve coverage without sacrificing realism.
Synthetic data isn't a shortcut. It's a way to guarantee safety, cover edge cases, and scale training without exploding costs.
How Coasty fits
Coasty runs computer use agents on real desktops and browsers, capturing realistic interaction data and trajectories. That data can be transformed into custom synthetic datasets tailored to your workflows, UI environments, and evaluation tasks. Coasty's offering is a custom, contact-led service. There is no self-serve dashboard or fixed pricing. To explore how synthetic data can accelerate your agent training and evaluation, book a data call with the Coasty data team.
If you're serious about building robust computer use agents, synthetic data isn't optional. Start by talking to the Coasty data team: book a data call at https://cal.com/coasty/coasty-data-call .