Package Library

The Gofasta library is a set of independent packages under pkg/. A scaffolded project imports a curated subset as its defaults — the same way any Go backend imports a curated set of community libraries. Each import is a default, not a requirement: delete one and replace it with a different library or a local implementation, and nothing else in the project has to change.

The pages below document each package’s public API, configuration, and the way the scaffold wires it.

Core infrastructure

Package	What it provides
`pkg/config`	Koanf-backed loader: `config.yaml` plus `GOFASTA_`-prefixed env overrides into a typed `AppConfig`, with `SetupDB` for all five drivers.
`pkg/logger`	Structured logging on `log/slog` — JSON or text, configurable level, context fields, trace-ID propagation.
`pkg/errors`	Typed domain errors that map to HTTP status codes, with stable error codes and a GraphQL error presenter.
`pkg/models`	`BaseModelImpl`: UUID primary keys, managed timestamps, soft delete, optimistic locking via `RecordVersion`.
`pkg/types`	Shared DTOs for pagination, sorting, error payloads, and common response envelopes.
`pkg/utils`	Pagination math, string case conversion, GORM sort/filter query builders.

HTTP and API surface

Package	What it provides
HTTP utilities	Request binding and validation, JSON response helpers, pagination support for handlers.
Middleware	CORS, rate limiting, request logging, authentication, panic recovery, request IDs.
`pkg/graphql`	Reusable gqlgen schema fragments for pagination, sorting, errors, and the health probe.
`pkg/health`	`/health`, `/health/live`, and `/health/ready` probes with per-dependency status.

Authentication and security

Package	What it provides
`pkg/auth`	JWT generation, validation, and refresh; claims management; auth middleware; Casbin-backed RBAC.
`pkg/session`	Server-side sessions over gorilla/sessions with cookie and filesystem stores.
`pkg/encryption`	AES-256-GCM authenticated encryption for data at rest.
Validators	Struct-tag validation on go-playground/validator with custom rules registered by the scaffold.

Data and storage

Package	What it provides
`pkg/cache`	One caching interface over an in-memory store or Redis, with per-key TTL.
`pkg/storage`	File storage across local filesystem and S3-compatible backends, including presigned URLs.
`pkg/seeds`	Ordered seeder registry — `Register(name, fn)` and `RunAll()`.

Communication

Package	What it provides
`pkg/mailer`	Outbound email over SMTP, SendGrid, or Brevo, with HTML template rendering and attachments.
`pkg/slack`	Slack messages via incoming webhooks or bot tokens — files, thread replies, block kit.
`pkg/whatsapp`	WhatsApp messaging across UltraMsg, Twilio, and the Meta Cloud API.
Push notifications	Mobile push via Firebase Cloud Messaging behind a pluggable `Sender` interface.
Notifications	Multi-channel dispatch across email, SMS, Slack, and in-app database delivery.
`pkg/websocket`	WebSocket hub with a connection registry, rooms, and broadcasting.

Background processing

Package	What it provides
`pkg/scheduler`	Cron scheduling on robfig/cron with 6-field expressions.
`pkg/queue`	Async tasks on asynq and Redis — concurrency, retries with backoff, scheduled delivery, priorities.
Resilience	Circuit breaking and retry-with-backoff via failsafe-go.

Operations and instrumentation

Package	What it provides
Observability	Prometheus metrics and OpenTelemetry tracing as HTTP middleware.
Feature flags	Flag evaluation through the OpenFeature Go SDK with swappable providers.
`pkg/i18n`	go-i18n translations from per-locale YAML, with `Accept-Language` resolution and pluralization.
Test utilities	testcontainers-backed PostgreSQL test databases with migrations applied.