Spectre is an OTP-native runtime for agents whose routing, state, policies, durability, and side effects remain explicit. This page is the shortest path from a new Mix project to a correct mental model of the runtime.

Your first path

Read these four pages in order:

  1. Overview explains what Spectre is, when it fits, and the safety boundary it preserves.
  2. Installation adds the stable package, formatter metadata, and read-only diagnostics.
  3. Getting Started builds an Agent and follows one turn through routing, policy approval, and explicit host execution.
  4. Architecture establishes ownership, trust boundaries, Runs, Instances, and the separation between conversational and operational work.

Do not start with every extension or durable subsystem. A deterministic local turn is enough to learn the public boundary; add persistence and integrations only when the application needs them.

Continue by goal

GoalContinue with
See complete applicationsTwo Realistic Agents
Choose routes and stage side effectsRouting and Actions
Own durable subject stateAgent Instances and Subjects, then Resumable Runs
Run long or recurring proceduresWork, Vigil, and the Operational Runtime
Deploy and verify a releaseProduction Operations and Testing
Integrate another package or host runtimeIntegration Boundaries and Stack
Look up functions and compatibilityPublic API and the Public API Manifest
Upgrade an existing applicationRead the current release notes, then the relevant migration guide

The guide for LLMs and coding agents is a separate, machine-oriented contract. Human readers should follow the path above first.