// Copyright (C) 2026 Industrial Algebra
// SPDX-License-Identifier: AGPL-3.0-only
//! Backends: concrete implementations of [`crate::agent::Agent`].
//!
//! - [`echo::EchoAgent`] is the deterministic, dependency-free reference
//! backend used to drive the engine in tests.
//! - The HTTP backend ([`http`] module, behind the `backend-http` feature)
//! calls an OpenAI-compatible chat-completions endpoint and is the first
//! real LLM backend.
//! - The multi-provider roster ([`roster`] module, behind the `backend-http`
//! feature) assigns authed providers to critic personas at random.
//! - The credentials config ([`credentials`] module, behind the `backend-http`
//! feature) reads provider keys and model overrides from a TOML file so
//! Proserpina can reach providers whose keys aren't in the environment.
pub use EchoAgent;