OpenNest/AGENTS.md

OpenNest agent instructions

Shared instructions; keep CLAUDE.md as the thin @AGENTS.md import. OpenNest is a .NET 8 Windows CNC-nesting application with cross-platform libraries.

Working rules

• Prefer Roslyn Bridge MCP for symbols, references and diagnostics when available; fall back to text search.
• Use var for locals and namespaces matching project directories. Follow .editorconfig; format only changed C# files with dotnet format OpenNest.sln --include <paths>, then repeat with --verify-no-changes. On Linux, prefix both commands with EnableWindowsTargeting=true.
• Keep instructions concise: commands, boundaries and non-obvious safeguards, not class inventories or session history. Update affected instructions and user-facing docs with behavior/build changes; put detailed contracts in docs/. User guides and their screenshots live in the separate ajisaacs/opennest-help repo: update or recapture them when a UI change alters a documented screen, and never rename a HelpTopics ID.
• Never commit design specs, implementation plans, progress notes or temporary benchmark reports. Keep working records under local, ignored .hermes/plans/ or .hermes/progress/; retain reusable verification procedures in docs/.
• Keep vendor manuals/full-text extracts out of source control unless redistribution is authorized. Write project-specific behavior summaries with citations, separating controller rules, machine macros and unconfirmed behavior.

Build and test

# Full solution: Windows
dotnet build OpenNest.sln

# Cross-platform suites: run independently on Linux/macOS/Windows
# Use Release for routine runs; use Debug explicitly for DEBUG-only work counters.
dotnet test OpenNest.Tests/OpenNest.Tests.csproj -c Release
dotnet test OpenNest.Engine.Tests/OpenNest.Engine.Tests.csproj -c Release
dotnet test OpenNest.IO.Tests/OpenNest.IO.Tests.csproj -c Release
dotnet test OpenNest.Server.Tests/OpenNest.Server.Tests.csproj -c Release

# Windows runtime tests
dotnet test OpenNest.WinForms.Tests/OpenNest.WinForms.Tests.csproj

After changing planning, contour preparation or geometry checks, run the problem-nest corpus (Category=ProblemNests, opt-in via OPENNEST_PROBLEM_NESTS_SERVER); no plate may rank below its baseline. Keep desktop-dependent tests in OpenNest.WinForms.Tests, never add a WinForms reference to OpenNest.Tests. Optional CHR fixtures use local OpenNest.Tests/test-config.json and skip when absent. On Linux, build Windows projects with -p:EnableWindowsTargeting=true; this is not Windows runtime verification. The headless console builds independently with dotnet build OpenNest.Console/OpenNest.Console.csproj.

Releases: follow the release procedure and scripts/Publish-Windows.ps1; workflow artifacts are candidates, not published releases. GitHub (ajisaacs/OpenNest) is the primary repository; Gitea is a read-only backup mirror.

Project map and boundaries

• OpenNest.Core: domain (Nest -> Plate -> Part -> Drawing -> CNC.Program), geometry, cutting strategies and diagnostics. Angles are radians; use Tolerance.Epsilon for geometry comparisons. OpenNest.Math shadows System.Math, so qualify the latter.
• OpenNest.Engine: whole-job API in Jobs/, interactive proposals via PlateFillService, fill strategies, best-fit pairs, packing, sequencing and rapid planning. INestingEngine.Solve(NestJob) returns stock IDs/poses; boundary adapters map drawings and materialize results. NestJobRunner validates its candidates before committing demand/stock accounting. Do not assume arbitrary plug-in output or interactive paths received that validation. Job identity is reference-based, not drawing-name-based.
• Built-in whole-job engines live in OpenNest.Engine/NestingEngines/<Name>/, named for the jobs they suit; see nesting engines. A change must beat that engine's current benchmark result with every layout valid. External plug-ins implement INestingEngine with a public parameterless constructor and load from Engines/ beside the host; keep their projects out of this solution.
• OpenNest.IO: ACadSharp import/export and ZIP-based .nest persistence; depends on Core only (an IO.Tests guard enforces it). Best fits persist only when callers pass BestFitCacheStore.Shared as NestReader/NestWriter.BestFitStore. All DXF-to-Drawing conversion goes through CadImporter: Import + BuildDrawing for editable/reporting flows, ImportDrawing for headless callers. Preserve source offsets, entity IDs, suppressed entities and bends. Bend repair is opt-in, requires explicit source units and may not alter cut geometry or unrelated marks.
• OpenNest: WinForms UI (Forms/, Controls/PlateView, Actions/). OpenNest.Data holds cross-platform persistence; new-nest defaults live in %APPDATA%\OpenNest\defaults.json (in Database mode, the server's shared copy once it holds one). Posts live in Posts/OpenNest.Posts.<Name>/ and deploy to the desktop output's Posts/ directory. Desktop nest edits go through BeginChange/RecordChange; see undo and redo.
• OpenNest.Console, OpenNest.Mcp, OpenNest.Api: front ends; OpenNest.Benchmark: whole-job engine comparisons; OpenNest.Gpu: GPU evaluators; OpenNest.Training: ML data collection. Benchmark timing comparisons require --parallel 1; validate layouts and fulfillment, not just elapsed time.

Geometry and ownership safeguards

• Marks are not material: use SpecialLayers.IsMaterial when deriving nesting/collision geometry; exclude rapid and scribe moves without removing them from display, cutting time or posts.
• Engine/validator collision paths retain the hand-written Collision kernel; its GPU port is on hold. Material-overlap diagnostics use Clipper2 per pair for connected shared-material islands and interior markers; see material-overlap diagnostics. Polygon consumers use ClipperBridge; directional-distance consumers retain native-arc offsets. Validation uses OffsetForValidation and NestTolerances.SpacingSlack, not conservative display/preparation padding; Auto Nest's layout check, the runner's candidate validation and the pre-post part-spacing review all find spacing candidates with Core's SpacingOutline and confirm them on NativeContours (the outline circumscribes arcs by more than the slack), so they agree; NestLayoutCheck.Clears skips the confirmation and stays stricter for engine certification. Do not loosen tolerances to hide failures.
• FillLinear geometry caches are per public call, keyed by Program reference identity; never share them across calls/threads. PartOverlapChecker is per check; parts/programs must not mutate during its lifetime.
• FillScore ranks count, utilization, compactness; exact ties keep the current layout. Custom comparers remain authoritative. Preserve extents' negative/nonfinite-input fallback, pair preparation and adjusted-column overlap checks. Do not remove bounds recomputations without threshold/rounding characterization.
• ObservableList events own drawing/plate quantity tracking; avoid double accounting. Cutoff parts are excluded from quantity, utilization and overlap checks.
• Cutoffs persist as definitions on Plate.CutOffs; apply through RegenerateCutOffs, never preview parts. Preserve sequence positions. Batch planning must finish before mutation and roll back on failure. Use PlateSequencing.Apply for automatic cutoff dependencies, with nominal spans/reference identity rather than trimmed geometry/names.
• A cutoff starts only at the origin-side edge: stock can be oversize, so the far edge is unknown. Only a head-locked overcut (CutOff.HeadLockOvercut, HeadHeightLock markers) may start its far-edge segment there; posts refuse it without lock codes.
• Fixed emissions (locked programs, drawing-pinned contours) are accepted as given: their violations warn on an UNVERIFIED proposal and never steer the search, while every planner-chosen motion stays strict. Plates without them must keep the PlanningCharacterizationTests digests.
• An empty diagnostic is not a clear result unless IsComplete. Posting must run checks before writing CNC output; warnings require explicit per-attempt consent, never a persisted bypass. Keep inputs stable through analysis/cancellation.
• Preserve symbolic G-code variable definitions/references in file round trips. Keep training bitmaps by default; inference checks predictor availability before scalar-only extraction.

Read the relevant contract before changing its behavior:

• Nest file format
• Directional slides and pair-spacing limits
• Lead-in placement (including the planner's eroded pierce for cutouts too small for their lead-in) and pierce zones: opt-in PierceDiameter clearance, the hole pole fallback and the planner's perimeter scrap fallback
• Breakoffs: tabbed scrap; Break-layer open cuts that are cut but are not material
• Tabbed cutouts: holes cut in pieces around Tab-layer spans that are material but never cut; nesting reads material through NestingMaterial.ForNesting, so nothing nests in them
• Support tabs: the nest's support grid, the center-of-gravity check, and Plan Cutting's tab placement for parts the grid cannot hold level
• Material-overlap diagnostics
• Automatic cutoffs and sequencing
• Pre-post verification
• Machine cutting defaults: the nest's machine supplies leads, kerf and cut-off settings for plates without their own parameters
• Shared settings: in Database mode machines, post settings, clamps and nest defaults come from the server once it holds them; offline uses the last copy read, read-only
• Cut-time estimates: simulator/Calculate Cut Time acceleration planner and placeholder machine limits
• Cincinnati CL and CI Fiber
• Fill verification: opt-in benchmarks, frozen oracles, Debug-only counters and predictor initialization. Zero Release counters do not prove work removal.
• Desktop auto-update: Velopack feed, UpdateFeedUrl setting and Deploy-OpenNest.ps1.
• Undo and Redo: whole-nest history, the recording rule, what a restore rebuilds and what is excluded.
• Desktop help: WebView2 help window, F1 topic IDs and the pinned help release both packaging scripts install.