# Architecture

Text Tools is a static React/Vite application wrapped in the shared Toolbox shell. `text/pipeline.ts` defines an ordered, typed list of transformations. `applyPipeline` starts from the exact source, applies enabled steps one at a time, checks expansion after every step, and returns the last successful output with per-step before/after counts and warnings.

Text encoding/decoding, line-ending conversion, bounded CSV parsing and Unicode-aware case primitives come from `@add-ideas/toolbox-helpers`. File decoding uses an explicit encoding and fatal-or-replacement choice; it does not guess a charset. Inverse JSON/HTML/URL/Base64/hex stages are strict: malformed syntax and non-UTF-8 byte output fail the step rather than being silently repaired. Column selection offers a quoted CSV mode that preserves embedded delimiters/newlines and a separate literal-delimiter-per-line mode. Recipe JSON carries a schema/app identity, accepts at most 100 supported steps, discards supplied IDs and assigns local monotonic IDs.

`text/evidence.ts` inspects original bytes before decoding, including BOM, exact UTF-8 validity/first invalid offset, zero-byte parity and CR/LF/CRLF counts. Artifact export emits the selected output bytes and a deterministic evidence document containing canonical-source and exact-output SHA-256 values, inventories, recipe and step reports. The document records that direct Toolbox handoff is unavailable in this release; the SDK 0.3.0 transfer contract is intentionally not activated until the Portal consumer rollout is coordinated.

Version 0.2 operations are synchronous and bounded, so the app creates no worker and has no persistence or server API. Relative entry and asset URLs keep the build relocatable below a nested portal path.