# AGENTS.md

## Project Overview
- **Primary Language**: C# (.NET 8 Console Application)
- **Key Libraries**: RestSharp, Newtonsoft.Json, System.Data.SQLite, Microsoft.Extensions.Configuration
- **Purpose**: Tumblr API data harvester for collecting notes, posts, likes, and replies, storing results in SQLite.

## Architectural Patterns
- CLI entry point in `Program.cs` with workflow orchestration
- `DataAccess.cs`: Database operations, `ApiKeyPool` (API key management), `APIAccess` (Tumblr client)
- `ResponseNotes.cs`: Tumblr API response models
- Round-robin API key rotation with rate-limit tracking
- Automatic console color assignment per API key for output differentiation
- No-argument mode (`Program.TraverseDirectory`) ingests `.txt` blog export files into `Posts` via `DataAccess.AddPost`. Recognized field prefixes live in `TraverseDirectoryFieldPrefixes`; `Body:` and `Downloaded files:` collect every following line up to the next recognized prefix (multi-line values). `RootURL` is populated from a `Reblog root url:` line the same way it's populated from the API-based `--likes` flow — both paths converge on `DataAccess.AddPost`'s `rootURL` parameter, which `UpdatePost` only overwrites when the incoming value is non-empty (existing `RootURL` is preserved otherwise)

## Developer Guidelines

### Code Formatting
- 4-space indentation, no tabs, match existing C# style
- PascalCase for public members, camelCase for locals
- Minimize code comments unless explicitly requested
- Use only existing project libraries; no new dependencies without confirmation
- Match accessibility modifiers (`public` for models, `internal` for helpers)

### Error Handling
- Wrap file/network operations in `try-catch`
- Log non-critical errors (e.g., config write failures) with `[Warning]` prefix
- Preserve console color state: use save/restore pattern for temporary color changes
- API rate limits must use `ApiKeyPool.MarkRateLimited()`/`MarkAvailable()`

### Testing
- No existing test suite; use xUnit if adding tests
- Test critical logic: `ApiKeyPool` init, color parsing, config persistence
- Avoid testing one-off CLI workflows

### Git Commit Messages
- Imperative mood ("Add feature" not "Added feature")
- Prefix with type: `feat:`, `fix:`, `chore:`, `docs:`
- Keep messages under 72 characters
- Never commit sensitive data (API keys/tokens)

### API Key Color Rules
- Unconfigured keys auto-assign colors from a preset palette
- Auto-assigned colors persist to `appsettings.json`
- All output for an active key uses its assigned color
- Temporary color changes (e.g., errors) must restore the key's color afterward