Feature Coverage

Prefect 3 features covered by this example repository, and gaps still to fill.

Coverage matrix

Feature	Covered	Example flows	Notes
@flow / @task	Yes	Basics 1--20	Core building blocks
Subflows	Yes	Subflows, Flow of Flows, Complex Pipeline	Nested @flow calls
.map() / .submit()	Yes	Dynamic Tasks, Advanced Map Patterns	Fan-out and parallel execution
Retries / retry delays	Yes	Retries and Hooks, Advanced Retries	Lists, jitter, condition functions
Task caching	Yes	Task Caching	INPUTS, TASK_SOURCE, cache_key_fn
Timeouts	Yes	Task Timeouts	timeout_seconds on tasks and flows
State hooks	Yes	State Handlers, Failure Escalation	on_failure, on_completion
allow_failure	Yes	Advanced State Handling	Downstream continues after failure
Parameters	Yes	Parameterized Flows	Typed defaults, runtime overrides
Results / persistence	Yes	Task Results, Result Persistence	persist_result, result_storage_key
Remote result storage	Yes	Remote Result Storage	result_storage=S3Bucket(...) on tasks/flows
Artifacts	Yes	Markdown Artifacts, Table and Link Artifacts, Progress Artifacts	Markdown, tables, links, progress tracking in UI
Tags	Yes	Tags	Decorator and context-manager
Custom run names	Yes	Task Run Names, Flow Run Names	Templates and callables
Structured logging	Yes	Structured Logging	get_run_logger(), log_prints
Events	Yes	Events	emit_event()
Blocks / Secret	Yes	Secret Block, Custom Blocks, DHIS2 flows	Block subclass, SecretStr
Variables	Yes	Variables and Params	Variable.get() / set()
Concurrency limits (local)	Yes	Concurrency Limits	concurrency() context manager
Async tasks/flows	Yes	Async Tasks, Concurrent Async, Async Flow Patterns	asyncio.gather()
flow.serve()	Yes	Flow Serve	In-process scheduling
flow.deploy()	Yes	Work Pools	Work pool + worker
prefect.yaml	Yes	Deployments directory	Declarative deployments
Schedules (cron/interval/rrule)	Yes	Schedules	All three schedule types
prefect.runtime	Yes	Runtime Context	Deployment-aware flows
Transactions	Yes	Transactions	transaction() for atomic groups
Interactive flows	Yes	Interactive Flows	Mock approval (real pause_flow_run() requires server)
Task runners (ThreadPool)	Yes	Task Runners	ThreadPoolTaskRunner
Pydantic models	Yes	Pydantic Models, Pydantic Validation	Type-safe data passing
S3 storage (prefect-aws)	Yes	S3 Parquet Export, DHIS2 GeoParquet Export	S3Bucket, MinIOCredentials
Notification blocks	Yes	Notification Blocks	Built-in blocks (Slack, Teams, Custom Webhook) with notify() interface
Webhooks	Yes	Webhook Block	Webhook block for outbound HTTP; inbound webhooks documented
Basic auth	Yes	Docker Compose stack	PREFECT_SERVER_API_AUTH_STRING / PREFECT_API_AUTH_STRING

Gaps -- features not yet covered

High priority (core Prefect 3 differentiators)

Feature	What it does	Complexity	Why it matters
Automations and triggers	Event-driven flow execution, deployment triggers, state-change reactions	Advanced	Core Prefect 3 differentiator for reactive orchestration
Global concurrency limits	Cross-flow resource throttling via API (vs local concurrency())	Intermediate	Important for shared-resource coordination across deployments
Rate limits	prefect.concurrency API-level rate limiting for tasks and flows	Intermediate	Prevents overwhelming external APIs in production

Medium priority (commonly used integrations)

Feature	What it does	Complexity	Why it matters
prefect-sqlalchemy	Database connections, parameterized SQL queries	Intermediate	Most common integration for data engineering
prefect-dbt	dbt Cloud/Core orchestration from Prefect flows	Advanced	Popular for analytics engineering teams
Docker/K8s work pools	Push-based execution to containers	Advanced	Production infrastructure patterns
GitHub storage deployments	Pull flow code from GitHub repos at runtime	Intermediate	GitOps deployment workflow
DaskTaskRunner / RayTaskRunner	Distributed task execution for CPU-heavy workloads	Advanced	Scaling beyond single-machine parallelism
pause_flow_run() (real)	Server-side flow pause with human-in-the-loop approval	Intermediate	Interactive flows example uses mock; real pause needs server

Lower priority (nice to have)

Feature	What it does	Complexity
Managed execution	Prefect Cloud managed infrastructure	Intermediate
Custom event triggers	Complex event-driven patterns with compound triggers	Advanced
Work pool priority	Priority-based flow run scheduling across pools	Intermediate
Flow run infrastructure overrides	Per-run infrastructure customization	Intermediate
Reverse proxy auth (SSO/OIDC)	oauth2-proxy + nginx/Caddy/Traefik for multi-user auth	Advanced
RBAC	Role-based access control (Prefect Cloud only)	N/A
Incident management	Prefect Cloud incident creation and response	N/A