Horus

Horus is a small Rust coding-agent framework with one headless gateway and a thin terminal client. One gateway process owns machine credentials, up to 32 concurrent chat agents, artifacts, usage statistics, and scheduled work.

Install

Download one horus-cli archive and checksum from GitHub Releases. It contains both horus and horus-gateway. Rust users can install both commands with Rust 1.89 or newer:

cargo install --locked horus-cli

Users upgrading from the earlier split packages should run cargo install --force --locked horus-cli once so Cargo transfers both commands to the CLI package.

Then run horus from the workspace it should own:

cd /path/to/repository
horus

On first use, the CLI initializes the machine-wide local gateway, pairs itself, saves its token, starts the gateway in the background, and opens /login when no provider is configured. The first configured model becomes the gateway default for new chats. Each CLI invocation creates an independent chat for its current directory; other terminal and app frontends can connect to the same gateway and open separate or shared chats. Workspace, model, reasoning, agent features, approval policy, and prompt are chat-scoped. The gateway owns the available-model catalog and new-chat default; a chat only selects from that catalog. The core horus crate is linked into the binaries and is not a separate runtime prerequisite.

Plaintext is limited to loopback. A remote gateway must listen with a TLS certificate and clients pair with tls://host:port; setting an explicit HORUS_GATEWAY_ENDPOINT disables automatic local management. See the gateway guide, CLI guide for manual and remote setup.

To run the Rust binaries from this checkout:

cargo build -p horus-cli
cargo run -p horus-cli --bin horus

Framework

Horus requires Rust 1.89 or newer.

[dependencies]
horus = "0.2"

The caller owns composition:

use std::path::Path;
use std::sync::Arc;

use horus::Result;
use horus::agent::{Agent, AgentConfig, create_agent};
use horus::backend::checkpoint::{CheckpointStore, sqlite::SqliteCheckpoint};
use horus::backend::model::{Model, ModelRouter, openai::OpenAi};
use horus::backend::sandbox::{ApprovalPolicy, Sandbox, local::LocalSandbox};
use horus::middleware::{Middleware, MiddlewareStack};
use horus::middleware::tools::Tools;

async fn build_agent(
    workspace: &Path,
    api_key: String,
    model_id: &str,
) -> Result<Agent> {
    let model: Arc<dyn Model> = Arc::new(OpenAi::new(
        api_key,
        "https://api.openai.com/v1",
        model_id,
    )?);
    let models = Arc::new(ModelRouter::new("default", model));
    let sandbox = Arc::new(Sandbox::new(
        Arc::new(LocalSandbox::new(workspace)?),
        ApprovalPolicy::On,
    ));
    let checkpoints: Arc<dyn CheckpointStore> =
        Arc::new(SqliteCheckpoint::new(workspace.join("horus.sqlite3"))?);
    let middleware: Vec<Arc<dyn Middleware>> = vec![Arc::new(Tools::coding())];

    create_agent(AgentConfig::new(
        models,
        sandbox,
        checkpoints,
        MiddlewareStack::new(middleware)?,
        "You are a concise coding agent.",
    ))
    .await
}

Frontends submit protocol::Op values and consume events from Agent. Framework capabilities may also contribute frontend-neutral commands, references, widgets, and rendered blocks. A frontend decides how those contributions look; capability implementations do not depend on terminal code. Interrupts target a specific turn, and events carry an optional submission ID so command-driven and unsolicited system events remain distinct.

Modules

Middleware declaration order is execution order. A loop may run with no optional middleware. The sandbox enforces approval policy for every approval-required tool. Static middleware prompt fragments are composed into the system prompt once when an agent is created; runtime hooks do not repeatedly append them to conversation state. Skills and subagents expose prompt builder overrides, while workspace instructions load a bounded root AGENTS.override.md or AGENTS.md when that middleware is installed. Subagents may set default model and reasoning choices at construction, with per-spawn overrides. Compaction defaults to 250,000 tokens. Its middleware uses a provider's native endpoint when advertised; otherwise it creates a rolling summary while retaining recent raw context. Checkpoint backends expose cursor-paginated session catalogs and sequence-bounded transcript pages. AgentConfig::initial_replay_batches controls the recent history rendered on resume; the complete compacted model checkpoint is loaded independently.

The local command sandbox currently uses Seatbelt on macOS and Bubblewrap on Linux. Linux must permit the selected bwrap binary to create user, PID, and network namespaces; AppArmor-restricted hosts need a matching Bubblewrap profile. If the platform sandbox is unavailable, command execution fails closed. The sandbox offers three approval policies: prompt before dangerous tools, allow tools without network, or allow tools with network. Filesystem confinement remains active in every mode. Tools::coding includes foreground execution plus bounded, session-owned background start, poll, and stop operations; background jobs end on completion, explicit stop, or session shutdown.

Contributing

Read AGENTS.md before changing the framework. It defines module ownership, capability extension points, required checks, and the no-compatibility rule for this initial release.

Release tags are intentionally separate:

• horus-vX.Y.Z publishes the framework crate and creates its GitHub Release.
• horus-gateway-vX.Y.Z publishes the gateway crate and attaches server binaries.
• horus-cli-vX.Y.Z publishes the CLI crate and attaches downloadable binaries to a GitHub Release.

Publish horus, then horus-gateway, then horus-cli, waiting for each dependency to appear in the crates.io index. Creating a tag is a release action; ordinary pushes and pull requests only run CI. The release workflow expects a CARGO_REGISTRY_TOKEN repository secret for the initial crates.io publications.

License

Licensed under Apache-2.0. See NOTICE for attribution to OpenAI Codex, Ratatui-derived work, and the Sora color palette.