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Squid Mesh is an open source workflow automation runtime for Elixir applications.

It is aimed at Phoenix and OTP apps that want to define and run durable workflows in code without rebuilding the runtime layer around retries, replay, inspection, cancellation, and scheduling.

Core Idea

• define workflows declaratively with triggers, payload contracts, steps, transitions, and retries
• run them durably on top of an existing Repo and Oban
• inspect run history with step and attempt details
• replay and cancel runs through a small public API
• activate recurring workflows through cron-backed triggers

Current Features

• manual triggers
• cron triggers
• step retries with exponential backoff
• built-in :wait and :log steps
• run inspection with history
• replay and cancellation
• HTTP tool adapter support

Example Workflow

defmodule Content.Workflows.PostDailyDigest do
  use SquidMesh.Workflow

  workflow do
    trigger :daily_digest do
      cron("0 9 * * 1-5", timezone: "Etc/UTC")

      payload do
        field(:feed_url, :string, default: "https://example.com/feed.xml")
        field(:discord_webhook_url, :string)
        field(:posted_on, :string, default: {:today, :iso8601})
      end
    end

    step(:fetch_feed, Content.Steps.FetchFeed)
    step(:build_digest, Content.Steps.BuildDigest)

    step(:post_to_discord, Content.Steps.PostToDiscord,
      retry: [
        max_attempts: 5,
        backoff: [type: :exponential, min: 1_000, max: 30_000]
      ]
    )

    transition(:fetch_feed, on: :ok, to: :build_digest)
    transition(:build_digest, on: :ok, to: :post_to_discord)
    transition(:post_to_discord, on: :ok, to: :complete)
  end
end

Running from Host App

SquidMesh.start_run(Content.Workflows.PostDailyDigest, %{
  discord_webhook_url: System.fetch_env!("DISCORD_WEBHOOK_URL")
})

Under the Hood

• Oban for durable execution and scheduling

• Jido for custom step actions

• Postgres for persisted run state

Status

This is still an early alpha release.

Current focus:

• API shape

• workflow contract

• runtime model

Links

• Hex: squid_mesh | Hex

• Docs: squid_mesh v0.1.1 — Documentation

• GitHub:

https://github.com/ccarvalho-eng/squid_mesh