# TokenGauge > TokenGauge is an independent, evidence-backed LLM API cost workbench for comparing dated provider rates, reconciling aggregate usage, and testing cost interventions without hiding quality failures. TokenGauge is open-source software maintained by Fablgen Agent. It is not affiliated with or endorsed by OpenAI or any listed model provider. Published prices are dated estimates linked to provider sources; provider invoices remain authoritative. Savings are not guaranteed. The public site includes free, no-login browser-local tools. Paid one-time plans unlock the complete evidence library, research atlas, encrypted bring-your-own-key connections, and larger experiment history or export windows. No plan includes provider API credits. The pricing page is authoritative for current plan and launch-offer details. ## Free tools - [AI API bill audit](https://tokengauge.enby.fish/audit): Reconcile aggregate input, cache-read, and output tokens against a dated rate card; entered values stay in the browser. - [Workflow cost ledger](https://tokengauge.enby.fish/ledger): Attribute aggregate usage to projects and features, import or export canonical CSV, and compare cost per accepted answer locally. - [Provider pricing directory](https://tokengauge.enby.fish/pricing): Browse dated model, region, context-tier, cache, and output rates with links to official provider sources. - [Provider comparison workbench](https://tokengauge.enby.fish/compare): Compare user-supplied workload, quality, retry, latency, and client-compatibility observations without invented provider benchmarks. - [Pricing change ledger](https://tokengauge.enby.fish/pricing/changes): Review effective dates, expiries, historical rows, and source-revalidation boundaries. ## Machine-readable data contract - [Pricing Feed v1](https://tokengauge.enby.fish/pricing.json): Public GET/HEAD JSON with the dated USD-per-million-token snapshot, provider/model/card IDs, cache and context dimensions, effective intervals, and row-level source links. - [Pricing Feed v1 schema](https://tokengauge.enby.fish/schemas/pricing-v1.schema.json): The stable JSON Schema. `effectiveFrom` is inclusive; `effectiveUntil` is exclusive. - [Tagged v0.5.0 fixture](https://raw.githubusercontent.com/fablgen-agent/tokengauge/v0.5.0/public/fixtures/pricing-v1.json): Pin this release snapshot and verify its published checksum for reproducible historical tests. - [Tagged v0.5.0 schema](https://raw.githubusercontent.com/fablgen-agent/tokengauge/v0.5.0/public/schemas/pricing-v1.schema.json): Pin the tagged contract definition with the fixture. - [v0.5.0 SHA-256 manifest](https://github.com/fablgen-agent/tokengauge/releases/download/v0.5.0/SHA256SUMS): Verify the downloaded release fixture and schema against this published manifest. - [Dependency-free consumer example](https://github.com/fablgen-agent/tokengauge/blob/v0.5.0/examples/pricing-feed-consumer.mjs): Validates the schema and semantic invariants, resolves one exact card, and fails closed for unknown, expired, out-of-band, or unpublished rates. Rows can be current, future, or historical and must be selected by their effective interval. Omitted bounds mean no known bound, not a permanent-rate guarantee. Schedule-labelled cards require caller-side selection using the provider's documented day, time, and timezone. Missing cards and `null` rates are unknown, never zero. The feed covers only its explicit token-price fields; provider invoices remain authoritative and unmodelled media, tool, storage, tax, credit, or account-specific charges require separate handling. ## Product and methodology - [Product overview](https://tokengauge.enby.fish/): Current scope, controlled demonstration, plan boundaries, and one-time access options. - [Evidence library](https://tokengauge.enby.fish/library): Evidence cards labelled as official facts, derived math, or test protocols; access varies by plan. - [Controlled A/B lab](https://tokengauge.enby.fish/lab): Run supported paired recipes with a connected ChatGPT plan or encrypted provider key; prompts and outputs are not stored. - [Cost attribution guide](https://tokengauge.enby.fish/guides/llm-cost-per-customer-feature): Separate provider billing from application attribution, retries, and accepted-answer economics. - [Autonomous agent token-budget guide](https://tokengauge.enby.fish/guides/autonomous-agent-token-budget): Check growing full-history requests before provider dispatch, cap output allowance, and stop without one final over-budget model call. - [Source repository](https://github.com/fablgen-agent/tokengauge): MIT-licensed application source, validation workflow, deployment notes, and public issue tracker. ## Commercial boundaries - [Plans and pricing](https://tokengauge.enby.fish/#pricing): One-time TokenGauge access; provider usage and billing remain separate. - [Cost attribution implementation](https://tokengauge.enby.fish/services/attribution): Fixed-scope implementation for one authorized Node.js/TypeScript or Python workflow. - [Application budget guard](https://tokengauge.enby.fish/services/budget-guard): Fixed-scope pre-call exposure reservation and post-call reconciliation for an authorized codebase. ## Trust and legal - [Privacy notice](https://tokengauge.enby.fish/privacy): Account, experiment, provider-key, payment, deletion, and backup data boundaries. - [Terms](https://tokengauge.enby.fish/terms): Product, billing, provider-usage, acceptable-use, and service-scope terms. ## Optional - [Research atlas preview](https://tokengauge.enby.fish/atlas): A sampled view of atomic candidates and compound configurations; rows are not claims of distinct proven methods. - [Experiment dashboard](https://tokengauge.enby.fish/dashboard): Reports paired-test token deltas rather than production savings or invoice totals.