AI Usage & Cost Explorer | Synthetic Demo

AI Usage & Cost Explorer | Synthetic Demo

Try the live demo with no installation: https://tribloc-ai-costs.pages.dev/

Hosted version The public version computes in each visitor's browser. Its ledger stays in that tab and resets on reload; usage records are not sent to a server. All six public preset scenarios passed. The optional local Node server remains available separately.

Project overview An independent, locally runnable demonstration of AI usage-cost estimation and a replay-aware ledger. All model names, usage records, project labels and prices are fictional. No provider API is called and no actual spending is measured.

The problem A cost total is only useful when its inputs, prices and calculation can be inspected. This demo makes the estimate traceable and shows how duplicate or conflicting submissions are handled before they can distort the local ledger.

My role I defined the architecture, scope, synthetic scenarios and acceptance criteria. Implementation was assisted by AI. This is an independent public portfolio demonstration, not a client engagement or a production cost-saving claim.

What was implemented A JavaScript application with an optional local Node.js server calculates estimates for four disjoint token buckets: uncached input, output, cache reads and cache writes. Exact integer arithmetic preserves decimal amounts. Each accepted record includes its fictional rate snapshot, breakdown and input fingerprint. Identical request-ID replays return the original record without increasing totals; changed content under that ID is refused. The browser supports six preset scenarios, custom rates and usage, ledger JSON inspection and reset.

Validation and evidence 49 automated tests passed on 17 October 2026, covering calculation precision, input validation, replay/conflict handling, aggregation, record isolation and local HTTP boundaries. Twelve browser checks passed, including custom rates, model switching, invalid inputs and reset. Source code, reports, a recorded example and local setup instructions are available in the public GitHub repository.

Scope and limitations Synthetic usage and fictional prices only. Estimates are not vendor bills, measured model usage or real spending. No LLM calls, credentials, customer systems or internal project code are included. The hosted ledger stays in one browser tab. The optional local Node server uses separate shared in-memory state. This is not a production billing system, production hosted service, tamper-proof audit store or security-audit result.

Source and local setup: https://github.com/truSwen/ai-usage-cost-explorer