> ## Documentation Index > Fetch the complete documentation index at: https://docs.trueparser.com/llms.txt > Use this file to discover all available pages before exploring further. # Plans and Limits > How TrueParser measures Document Units, request limits, and usage visibility. Every TrueParser application is governed by plan-based limits. These limits are enforced automatically at runtime and determine how much parsing work your application can perform. ## Overview TrueParser tracks three separate kinds of usage: * API request limits * Document Unit quotas * byte usage In product and plan language, TrueParser refers to one countable unit of parsing consumption as a **Document Unit**. ## What Is a Document Unit? A **Document Unit** is the common product term for one countable unit of parsing work. Depending on parser family, one Document Unit may correspond to: * a page * an email/message item * a SQL statement * a byte-based processing measure for size-accounted families This lets TrueParser present one consistent commercial model across very different parsing engines. ## Request-Rate Limits TrueParser also enforces request-rate limits for API traffic. Current public request-rate behavior: * request limits are app-scoped * the current API uses a requests-per-minute limit * request-rate limits are separate from Document Unit quotas If your application exceeds the allowed request rate, the API returns `429 Too Many Requests`. ## Document Units by Family The current Document Unit mapping is: | Family | One Document Unit means | | -------- | ------------------------------------ | | PDF | One page | | MsOffice | One page | | OpenDoc | One page | | MailKit | One top-level email/message item | | SQL | One statement | | GIS | 1 usage unit per 100 KiB, rounded up | | CAD | 1 usage unit per 100 KiB, rounded up | | Parquet | 1 usage unit per 100 KiB, rounded up | Document Unit is the product term used across plans, pricing, quota enforcement, and customer-facing usage discussions. The exact technical counting rule depends on the parser family listed above. Some families are counted by page or item, while CAD, GIS, and Parquet are counted in 100 KiB usage units rounded up from the uploaded payload size. That means a 50 KiB file still counts as 1 usage unit. ## Quota Windows Document Unit quotas are enforced across multiple windows: * per document * hourly * daily * weekly * monthly If a parsing job would exceed the allowed quota window, TrueParser rejects or fails that operation under the current plan rules. ## Byte Usage TrueParser also tracks accepted upload size in bytes. Byte tracking is useful for: * visibility * telemetry * operational monitoring Byte usage is separate from Document Units. A large upload does not automatically mean a large Document Unit count, and vice versa. The platform also enforces a maximum upload size per document under your plan. For size-accounted families such as CAD, GIS, and Parquet, the platform counts usage in 100 KiB units rounded up from the uploaded payload size rather than page-based counting. Any non-empty upload below 100 KiB still counts as 1 usage unit. ## Usage Visibility You can inspect current usage through the Usage API. The current API exposes usage as separate request, quota, and byte windows rather than one aggregated usage object. At a high level, the Usage API provides visibility into: * request-rate usage * Document Unit quota windows * byte usage windows ## Quota Errors When your application exceeds a limit, the current API can surface errors such as: * `rate_limit_exceeded` * `quota_exceeded` * `document_quota_exceeded` At a high level: * `rate_limit_exceeded` means your application exceeded an API traffic limit * `quota_exceeded` means your application exceeded a rolling Document Unit window * `document_quota_exceeded` means a single document exceeded the allowed per-document quota