Hi everyone,

I recently made Spectre public.

Spectre is an OTP-native Elixir runtime for building AI agents while keeping routing, state, policies and side effects explicit.

I started working on it because I wanted to use agents inside real Elixir applications without moving all the application logic into prompts or hiding it behind a large framework.

The basic idea is simple:

• the model can help classify requests and propose actions;

• deterministic application policies decide whether protected actions are allowed;

• approvals update the agent state but do not automatically execute anything;

• the host application remains responsible for side effects.

For example, an agent may propose sending a message, changing data or deleting an account. Spectre can represent that action, request confirmation when required and return the result to the application. The application still decides how and when the action is executed.

Spectre uses a small DSL to describe the stable shape of an agent, including routes, policies, actions and interruptions. Normal Elixir modules continue to own the business logic, storage, permissions and integrations.

A small example:

defmodule MyApp.SupportAgent do
  use Spectre.Agent

  actions MyApp.SupportActions do
    protect(:delete_account, with: :delete_account_confirmation)
  end

  policy :delete_account_confirmation do
    request(:confirm_delete_account)
    accept(:confirmed_delete, regex: ~r/^yes, delete it$/i)
    reject(:cancel_delete, regex: ~r/^(no|cancel)$/i)
    attempts(3, then: :cancel_pending)
  end

  flow :support do
    on :PRICING, regex: ~r/\b(price|pricing|cost)\b/i do
      reply(:pricing)
    end

    on :DELETE_ACCOUNT, regex: ~r/\bdelete my account\b/i do
      action(:delete_account)
    end
  end
end

The project is designed around OTP processes and explicit state transitions rather than autonomous execution hidden inside the framework.

I am also developing optional companion libraries for areas such as tool planning, browser interaction, memory and mission planning. They are separate projects because not every agent needs all of these capabilities, and I prefer being able to add only the parts required by an application.

• spectre_kinetic for mapping instructions to validated function-call candidates.
• spectre_lens for browser interaction and agent-readable web pages.
• spectre_mnemonic for working and durable agent memory.
• spectre_directive for missions and plans that can change when new information is discovered.

Spectre is currently in public preview. I am already using it in a few applications, but some APIs may still evolve as I continue testing the design in real projects.

Feedback about the API, architecture and documentation is very welcome.

Source code: