Contributing to OpenTools: 4 Pure-TypeScript First Tasks with Zero Framework Overhead

Most web repositories require hours of environment setup: configuring cloud accounts, seeding local databases, mocking microservices, and untangling complex state management layers. OpenTools takes a radically different architectural stance: every tool engine is a pure TypeScript function over bytes. - No network calls: Tools run in browser tabs with connect-src 'none'. - No databases or servers: Inputs are Uint8Array buffers or strings; outputs are transformed buffers or strings. - Zero mocking required: Tests feed real file fixtures into pure functions and inspect the results. - Instant feedback: Run npm test, change one function, and watch your tests pass. Here is the codebase reality by the numbers: - lib/tools/subtitles/core.ts — 561 lines, 59 unit tests. - lib/tools/archive/zip-reader.ts — 413 lines, 21 unit tests. - lib/tools/audio/mp3-frames.ts — 354 lines, 14 unit tests. Below are four genuinely open, bite-sized tasks ready for contributors.

### 1. ZIP64 Archive Reader Support - Where it starts: lib/tools/archive/zip-reader.ts:214 - Current behavior: Throws an explicit error: "This is a ZIP64 archive — over 4 GB or over 65,535 files. This page reads standard ZIP archives only." - The task: Parse the ZIP64 End of Central Directory locator and record, and read extra field 0x0001 for 64-bit offsets and uncompressed lengths. - Why it is a great starter: Pure binary parsing from the public PKWARE specification. The refusal error is already written and tested; making it return valid entries turns the refusal into capability. --- ### 2. TTML / DFXP Subtitle Format Parser - Where it starts: lib/tools/subtitles/core.ts:11 - Current behavior: SubtitleFormat supports 'srt' | 'vtt' | 'sbv' | 'lrc' | 'ass'. - The task: Add TTML (Timed Text Markup Language / DFXP XML) to the format union. Parse XML timing cues and text into standard Cue objects. - Why it is approachable: TTML is XML, making it straightforward to parse in TypeScript. Adding it automatically lights up all 14 subtitle workbench operations (sync, retiming, conversion) for TTML files simultaneously. --- ### 3. SCC Closed Caption Decoder - Where it starts: lib/tools/subtitles/core.ts:11 - The task: Implement an SCC (Scenarist Closed Caption) parser. - Difficulty: Stretch item. SCC uses hex-encoded CEA-608 words and requires drop-frame timecode arithmetic. A rewarding challenge for developers interested in broadcast video standards. --- ### 4. iPhone Safari Dropzone File Handoff - Where it starts: docs/DROPZONE_FILE_HANDOFF.md - Current behavior: Dropping a file on the homepage carries it to the destination tool on Chromium (Chrome/Edge/Android), but WebKit (Safari/iOS) fails to hydrate the target input. - The task: Solve the WebKit file transfer issue documented in docs/DROPZONE_FILE_HANDOFF.md. - Why it is outstanding: The failing tests are already written and committed, marked test.skip on WebKit in e2e/dropzone-handoff.spec.ts. A contributor does not have to guess what success means: you unskip the tests and make them green. All dead ends and hypotheses are already documented.

Getting up and running takes two commands: ``bash git clone https://github.com/mgbuilderos/opentools.git cd opentools npm install npm test ` Our rule is simple: **the tests are the specification.** If you pick an item, implement the parser, add unit tests for valid and malformed files, and npm run qc` passes 8/8 gates, your contribution is technically sound. Explore our repository CONTRIBUTING.md guide and issue templates to claim an item!