# Acts workflow engine
[](https://github.com/yaojianpin/acts/actions?workflow=rust)
[](https://github.com/yaojianpin/acts/actions?workflow=test)
Acts is a fast, lightweight, extensiable workflow engine that executes workflows defined in YAML format.
Unlike traditional workflow engines (such as BPMN). Acts uses a message-driven architecture to execute and distribute messages.
Acts uses Step, Branch, Act to build the workflow. Step and Branch are the workflow stucture to run in sequence or to step into different branch by condition. Act is responsible for the action execution.
## Key Features
### Fast
Write in Rust, No virtual machine.
1. bechmark with memory store
```txt,no_run
load/from_yml time: [46.130 µs 46.411 µs 46.666 µs]
thrpt: [21.429 Kelem/s 21.547 Kelem/s 21.678 Kelem/s]
deploy/model time: [192.09 µs 197.48 µs 204.39 µs]
thrpt: [4.8927 Kelem/s 5.0639 Kelem/s 5.2059 Kelem/s]
start/proc time: [684.94 µs 794.32 µs 955.33 µs]
thrpt: [1.0468 Kelem/s 1.2589 Kelem/s 1.4600 Kelem/s]
act/act time: [20.216 µs 21.544 µs 23.957 µs]
thrpt: [41.741 Kelem/s 46.417 Kelem/s 49.467 Kelem/s]
store_mixed/proc_crud/1000
time: [44.543 µs 45.109 µs 46.292 µs]
thrpt: [21.602 Kelem/s 22.169 Kelem/s 22.450 Kelem/s]
```
### Lightweight
The lib size is about 4.6mb now.
### Extensiable
- store collection extension
support creating external store, please refer to the code under `crates/acts-store/src/postgres`.
- pakcage extension
support creating custom package, please refer to the code under `example/custom_pakcage`.
## Installation
The easiest way to get the latest version of `acts` is to install it via `cargo`
```bash
cargo add acts
```
## Documents
[`Chinese`](https://yaojianpin.github.io/acts/zh/)
[`English`](https://yaojianpin.github.io/acts/en/)
## Quickstart
1. Create and start the workflow engine by `engine.new()`.
2. Load a yaml model to create a `workflow`.
3. Deploy the model in step 2 by `engine.executor(&principal).model()`.
4. Config events by `engine.channel()`.
5. Start the workflow by `engine.executor(&principal).proc()`.
```rust,no_run
use acts::{Engine, Principal, Vars, Workflow};
#[tokio::main]
async fn main() {
let engine = Engine::builder().start().await.unwrap();
// create yaml workflow model
let model = r#"
id: my_model
name: my model
steps:
- name: step 1
uses: acts.transform.set
params:
a: 10
- name: step 2
uses: acts.transform.code
params: |
return { data: a + 10 };
"#;
let workflow = Workflow::from_yml(model).unwrap();
// The executor acts for a caller: this one is the engine's own, which is
// what an embedder that drives the engine itself passes. `Principal` is
// also what the ACL in an `[acl]` config section decides.
let executor = engine.executor(&Principal::unrestricted());
executor
.model()
.deploy(&workflow, None)
.await
.expect("fail to deploy workflow");
let mut vars = Vars::new();
// set the input value
vars.set("a", 0);
// set the pid or auto generate by engine
vars.set("pid", "w1");
// start workflow by model id
executor
.proc()
.start(&workflow.id, vars)
.await
.expect("fail to start workflow");
// create channel to receive messages
let chan = engine.channel();
chan.on_start(|e| async move {
println!("start: {}", e.start_time);
});
chan.on_message(|e| async move {
println!("message: {:?}", e);
});
chan.on_complete(|e| async move {
println!("outputs: {:?} end_time: {}", e.outputs, e.end_time);
});
chan.on_error(|e| async move {
println!("error on proc id: {} model id: {}", e.pid, e.mid);
});
}
```
## Examples
Please see [`examples`](https://github.com/yaojianpin/acts/tree/main/examples)
## Model Usage
The model is a yaml format file. where there are different type of node, including [`Workflow`], [`Branch`], [`Step`].
```yml
name: model name
# workflow default inputs vars
vars:
- name: value
value: 0
# schema for inputs and outputs
inputs:
- name: value
title: Value
desc: Set value when starting workflow
type: number
# triggers to start the workflow
on:
- id: event1
kind: manual
# workflow steps
steps:
- name: step 1
# init with interrupt request to client
# and make sure complete the action with 'list' var
uses: acts.core.irq
- name: step 2
# workflow branches to run by condition
branches:
- name: branch 1
if: value > 100
steps:
- name: step 3
uses: acts.core.msg
- name: branch 2
if: value <= 100
steps:
- name: step 4
uses: acts.core.parallel
params:
in: ${{ list }}
acts:
- uses: acts.core.irq
- name: final step
```
### Vars
In the [`Workflow`], you can set the `vars` to init the workflow vars.
```yml
name: model name
vars:
- name: a
value: 100
steps:
- name: step1
uses: acts.transform.code
params: |
// get the a variable
let v = a + 100;
// do somthing else
```
The vars can also be set by starting the workflow.
```rust,no_run
use acts::{Engine, Principal, Vars, Workflow};
#[tokio::main]
async fn main() {
let engine = Engine::builder().start().await.unwrap();
let executor = engine.executor(&Principal::unrestricted());
let mut vars = Vars::new();
vars.set("input", 3);
vars.set("pid", "w2");
executor.proc().start("m1", vars).await.unwrap();
}
```
### Options
In the [`Workflow`], you can set the `exposes` to filter the outputs.
```yml
name: model name
exposes:
- name: output_key
steps:
- name: step1
uses: acts.transform.set
params:
output_key: 100
```
### Steps
Use `steps` to add step to the workflow
```yml
name: model name
steps:
- id: step1
name: step 1
- id: step2
name: step 2
```
For more acts example, please see [`examples`](https://github.com/yaojianpin/acts/tree/main/examples)
#### step.catches
Use the `catches` to capture the `step` error.
```yml
name: a catches example
id: catches
steps:
- name: prepare
id: prepare
uses: acts.core.irq
- name: step1
id: step1
uses: acts.core.irq
# catch the step errors
catches:
- name: catch step 1
id: catch1
uses: acts.core.irq
if: $ecode() == "err1"
- name: catch step 2
id: catch2
uses: acts.core.irq
if: $ecode() == "err2"
- name: final
id: final
```
#### step.timeouts
Use the `timeouts` to check the task time.
```yml
name: a timeout example
id: timeout
steps:
- name: prepare
id: prepare
uses: acts.core.irq
- name: step1
id: step1
uses: acts.core.irq
# check timeout rules
timeouts:
# 1d means one day
# triggers act2 when timeout
- uses: acts.core.irq
id: act2
if: $cost_in('1d')
# 2h means two hours
# triggers act3 when timeout
- uses: acts.core.irq
id: act2
if: $cost_in('2h')
- name: final
id: final
```
### Branches
Use `branches` to add branch to the step
```yml
name: model name
steps:
- id: step1
name: step 1
branches:
- id: b1
if: v > 0
steps:
- name: step a
- name: step b
- id: b2
else: true
steps:
- name: step c
- name: step d
- id: step2
name: step 2
```
For more acts example, please see [`examples`](https://github.com/yaojianpin/acts/tree/main/examples)
The active backend is created externally and passed to
`EngineBuilder::set_store` — when unset, an in-memory store is used. The
persistent backends live in the `acts-store` crate:
```bash
cargo add acts-store --features sqlite
```
```rust,ignore
use acts::Engine;
use acts_store::SqliteStore; // or PostgresStore / RedisStore / NatsStore / SledStore
use std::sync::Arc;
#[tokio::main]
async fn main() {
let store = SqliteStore::open("data/acts.db").await.unwrap();
let engine = Engine::builder()
.set_store(Arc::new(store))
.start()
.await
.unwrap();
}
```
Backends enabled by the matching `acts-store` feature:
- `MemoryStore` — built into `acts`, in-memory store, no persistence (default when unset)
- `SqliteStore` — `acts-store` feature `sqlite`
- `PostgresStore` — `acts-store` feature `postgres`
- `RedisStore` — `acts-store` feature `redis`
- `NatsStore` — `acts-store` feature `nats`
- `SledStore` — `acts-store` feature `sled`
Custom stores can be built by implementing `acts::KvStore` and passed to
`set_store` the same way.
## Package
Please see the example `example/pakcage`.
## Acts-Server
Create a acts-server to interact with clients based on grpc.
please see more from [`acts-server`](https://github.com/yaojianpin/acts-server)
## Client channels
- rust https://github.com/yaojianpin/acts-channel
- python https://github.com/yaojianpin/acts-channel-py
- go https://github.com/yaojianpin/acts-channel-go
## Roadmap
acts:
- runtime
- [x] model (Workflow, Branch, Step, Act)
- [x] scheduler (Config, Builder, Node, Process, Task, Queue, Event)
- [x] javascript runner
- [x] cache
- [x] plugin register
- [x] package register
- [x] snapshot register
- [x] message channel
- triggers
- [x] manual
- [x] hook
- [x] chat
- [x] schedule
- store
- [x] memory
- [x] sqlite
- [x] postgres
- [x] nats
- [x] redis
- [x] sled
- packages
- core
- [x] irq
- [x] msg
- [x] block
- [x] action
- [x] parallel
- [x] sequence
- [x] subflow
- transform
- [x] set
- [x] code
- app
- [ ] form (plugins/form)
- [ ] ai (plugins/ai)
- [x] state (packages/acts-package-state)
- [x] http (packages/acts-package-http)
- [x] shell (packages/acts-package-shell) support nushell, bash and powershell
- [x] pubsub (packages/acts-package-nats)
- [ ] database (plugins/database)
- [ ] mail (plugins/mail)
- [x] doc (doc/)
- plugins
- [x] grpc (plugins/acts-plugin-grpc)
- [x] web (plugins/acts-plugin-web)
- [x] nats (plugins/acts-plugin-nats)
- [ ] obs (plugins/acts-plugin-obs)