README
¶
Packtrail examples
Each example is a self-contained main package with its own flow definitions
and NATS namespace, so they can run against the same server without colliding.
All of them need a reachable NATS Server 2.12+ with JetStream enabled:
nats-server -js
Run the examples from the repo root (two of them load flow YAML from a
relative flows/ directory) and pass --nats if the server is not on
nats://127.0.0.1:4222.
| Example | Namespace | Shows |
|---|---|---|
embedded |
acme |
Engine + built-in nats-task workers in one process: WithFlowsDir, Server.Handle, fanout/fanin, a signal gate, reconcile schedules, Server.Results. |
worker |
packtrail |
A standalone external task service speaking pkg/protocol — no engine import. Run it next to embedded (same --namespace) and the two load-balance the same subjects via the shared queue group. |
custom-invoker |
agents |
The pluggable Invoker seam: WithInvoker("agent", …) drives task nodes by target name, a choice node routes on the triage agent's output (results.triage.category), WithResultCache dedupes redelivered side effects. |
async |
async-demo |
Long-running work off the critical path: WithAsyncInvoker + invoker/asyncqueue run slow fanout branches on a durable work-queue while the execution parks as waiting; flow built as a Go-struct FlowDef. |
approval |
orders |
Human-in-the-loop: a signal node with an on_timeout fallback, Server.Signal to approve, Server.Cancel to abandon, and WithHistory + Server.History for the durable step-by-step trace. |
go run ./examples/embedded # engine + in-process workers, one execution
go run ./examples/worker --namespace acme # optional: external workers for the run above
go run ./examples/custom-invoker # two executions routed by a simulated agent
go run ./examples/async # slow branches on the async work-queue
go run ./examples/approval # one approved order, one cancelled order
To watch any of them in the dashboard, point packtrail-ui at the example's namespace:
go run ./cmd/packtrail-ui --namespace agents --addr :8088
Directories
¶
| Path | Synopsis |
|---|---|
|
Command approval demonstrates human-in-the-loop control: a signal node parks the execution until an external approval arrives (with a timeout fallback), Cancel abandons an execution an operator no longer wants, and WithHistory records a durable step-by-step trace queryable with Server.History.
|
Command approval demonstrates human-in-the-loop control: a signal node parks the execution until an external approval arrives (with a timeout fallback), Cancel abandons an execution an operator no longer wants, and WithHistory records a durable step-by-step trace queryable with Server.History. |
|
Command async demonstrates long-running work off the engine's critical path.
|
Command async demonstrates long-running work off the engine's critical path. |
|
Command custom-invoker demonstrates packtrail's defining feature: the pluggable Invoker seam.
|
Command custom-invoker demonstrates packtrail's defining feature: the pluggable Invoker seam. |
|
Command embedded shows packtrail running as a single microservice: the engine and the task workers live in one process, importing only the public github.com/henomis/packtrail package.
|
Command embedded shows packtrail running as a single microservice: the engine and the task workers live in one process, importing only the public github.com/henomis/packtrail package. |
|
Command worker is a tiny external task service for the research-pipeline flow, demonstrating the pkg/protocol request/reply contract without importing the packtrail engine at all.
|
Command worker is a tiny external task service for the research-pipeline flow, demonstrating the pkg/protocol request/reply contract without importing the packtrail engine at all. |
Click to show internal directories.
Click to hide internal directories.