Nodes

Nodes are the individual steps in a workflow. Each node has a type, configuration, and connections.

Node structure

nodes:
  - name: "fetch_data"      # Unique identifier
    type: "http/request"    # Node type
    config:                 # Type-specific config
      url: "https://api.example.com"
      method: GET
    input:                  # Optional input mapping
      query: "{{ trigger.body.query }}"

Built-in types

Core nodes

Type	Purpose
core/log	Log to stdout
core/condition	Branch based on condition
core/sleep	Delay execution
core/template	Transform data

Data nodes

Type	Purpose
postgres/query	PostgreSQL operations
redis/get	Redis read
redis/set	Redis write

HTTP nodes

Type	Purpose
http/request	Generic HTTP call
http/webhook	Return response

Message nodes

Type	Purpose
slack/post	Send Slack message
discord/post	Send Discord message
kafka/produce	Publish to Kafka

Custom nodes

Build nodes in Rust:

use r8r_sdk::{Node, Context, Result};

#[derive(Node)]
#[node(name = "custom/hello")]
struct HelloNode {
    name: String,
}

impl Node for HelloNode {
    async fn execute(&self, ctx: Context) -> Result<Value> {
        Ok(json!({ "message": format!("Hello, {}!", self.name) }))
    }
}

Register in r8r.toml:

[nodes]
custom = "./nodes"

Input/output

Nodes communicate via JSON:

nodes:
  - name: "fetch"
    type: "http/request"
    # Outputs: { "status": 200, "body": {...} }

  - name: "process"
    type: "core/template"
    input: "{{ fetch.body.items }}"
    # Receives the items array

Error handling

Per-node error control:

nodes:
  - name: "api_call"
    type: "http/request"
    config: { ... }
    on_error:
      action: retry
      max_attempts: 3
      delay: 5s