Architecture and operations describe the current YATM v1 development line; research records the evidence and open questions behind further work. Start with installation, the v0.1.x upgrade, Library and Media workflows, or live Locations. Published versions and their change notes belong to GitHub Releases; this tree is not a release archive.

Pre-stable Compatibility

The required compatibility baseline is the supported v0.1.x migration/import path. Until the first stable v1 release, changes to data formats, APIs, entities, schemas, Job bundles and metadata backups between unpublished or pre-stable v1 builds require no compatibility layers or version/revision bumps. The persistence contract owns the current artifact identities and versions independently of software release numbers.

Configured Tape scripts have a separate, long-term compatibility requirement. Upgrades preserve user adapters wherever possible; a necessary incompatible change requires explicit approval and an actionable notice before upgrade, including pre-stable releases. The Tape script contract owns that boundary.

Known incompatible installations are rejected before writes. Their data is retained until the operator chooses backup, migration, conversion or reinstallation; YATM never clears databases or physical files automatically. Disposable development fixtures are regenerated only through an explicit reset. Remove this temporary rule when preparing the first stable v1 release and replace it with the published stable upgrade policy.

Current Architecture

Operations

Release Packages

The release package includes this index and the four operator guides: installation, migration, Library/Media workflows and Locations. Architecture, research and developer validation remain repository documentation; release packaging uses an explicit allowlist rather than copying the whole tree.

Research

Tape capacity and safe completion

Research is published with the repository. Each study states its objective, source versions, confirmed findings, community observations, unresolved questions and criteria for evaluating possible approaches. A study describes the current state of knowledge; it does not establish implemented behavior or authorize experiments and production changes.

Documentation Ownership

Every maintained fact has one owner. Other documents link to that owner instead of restating it.

Location	Owns	Does not own
Root `README.md`	Released product introduction, quick start and documentation entry points	Development status, architecture detail or repeated runbooks
Root `CONTEXT.md`	Domain vocabulary and core domain invariants	Schemas, algorithms, task notes or UI layout
Root `AGENTS.md`	Contributor rules, safety gates, repository layout and required verification	Product or architecture contracts
`docs/architecture/`	Current implemented behavior, module interfaces, invariants and durable constraints	Proposals, implementation plans, acceptance transcripts or superseded behavior
`docs/operations/`	Current setup, migration, use, maintenance and reproducible validation	Domain definitions or another architecture specification
`docs/research/`	Public technical studies, evidence, limitations and evaluation of possible approaches	Product guarantees, implementation backlogs, private incident reports or raw acceptance logs
`.agents/skills/yatm/`	Installed agent operating and safety instructions	Human-facing architecture or change history

Decision Authority

Within overlapping scope, broader accepted constraints bound narrower descriptions: the repository engineering rules, the domain invariants and compatibility policy, the architecture overview, area architecture, operations guides, and finally implementation and tests. A lower level may provide evidence and implementation detail, but its existence cannot justify complexity or override a broader decision. When they conflict, update the lower-level documents, code and tests together.

The repository intentionally has no documentation archive, ADR archive, design backlog or redirect stubs. Git already retains deleted text and rationale. Implementation plans belong in an Issue or pull request; public research follows the scope above. Published change notes belong to GitHub Releases. Raw acceptance logs, checksums, measurements, screenshots and host-specific reports belong in CI artifacts rather than Markdown.

Update Workflow

Establish the intended behavior from the decision authority above, then inspect CONTEXT.md, the owning document and the implementation. A mismatch is something to resolve, not a reason to promote the current implementation into a requirement.
Update the implementation, semantic tests, owning architecture document and affected operating guide together. Describe the final behavior in present tense; remove the replaced text instead of marking it historical, implemented or superseded.
Keep unsettled implementation designs in a PR or Issue. Public studies may evaluate alternatives in docs/research/, with evidence, assumptions and remaining proof clearly identified. After implementation, update the current architecture and link to research for supporting evidence. Update or remove invalidated research conclusions instead of accumulating superseded studies.
Keep implementation detail only when callers or maintainers must know it to use the module correctly. Function names, CSS placement, one measurement, one candidate checksum and step-by-step development history belong in code, tests or verification output.
Keep repository documentation self-contained. Every repository-relative link or file reference must resolve to a tracked file, or to a new file committed in the same change; external references use stable public URLs. Private notes, ignored artifacts and machine-local paths are never sources for repository documentation.
Before delivery, run make check or at minimum node dev/check-documents.mjs and git diff --check. The document check enforces the allowed tree, complete index, valid relative links and the absence of private/history references.

For research, use official specifications and source code together with relevant original community reports and maintainer responses. Record what was observed, what was actually resolved and which explanations remain hypotheses; a forum's resolved label alone is not evidence of a verified fix. Use stable public citations and concise summaries. Keep credentials, local paths, device identifiers, private host details and raw logs out of public studies; include only the technical context needed to assess the evidence. Hardware measurements establish the tested configuration's behavior, while general guarantees require an applicable specification or other evidence with a defined scope.

Use English Markdown, short topic-based kebab-case filenames and repository-relative links. Current architecture filenames are version-independent. Adding a new documentation file requires a distinct current owner that cannot be expressed clearly in an existing file; update this index in the same change.

UI Prototypes

Build UI prototypes with the existing React modules, styling and layout, and capture their rendered pages for review. Store temporary sources and screenshots under ignored frontend/.drafts/, then remove them after the accepted behavior and constraints have been recorded in the owning current architecture document. Generated concept images are not interface specifications.