Bascule

Identity-aware SSH proxy for modern infrastructure.

Bascule authenticates operators via SSH keys or AI agent tokens, then connects them to a local shell, remote host, or ephemeral container. No agents to install. No control plane. One binary.

Quick Start

cargo build --release -p bascule-server
./target/release/bascule --config config/bascule.example.toml
# In another terminal:
ssh -p 2222 localhost

See docs/quickstart.md for Docker, Helm, and container mode.

Features

Session Backends

Mode	Config	Description
Local PTY	(default)	Spawn a local shell process
Remote Proxy	[proxy]	Forward to a remote SSH host
Container	[container]	Ephemeral container per session (Docker/Podman/nerdctl)
Kubernetes	[k8s]	Shared jumphost with shell sidecar (config ready, runtime coming)

Authentication

• SSH Keys — standard OpenSSH authorized_keys files
• Accept All — development only, accepts any key
• Entra Agent ID — Microsoft AI agent identity (--features agent-id)
• SPIFFE/SPIRE — workload identity (config ready, runtime coming)

Security

• Session limiting (semaphore-based max_sessions)
• Container hardening (--cap-drop ALL, --security-opt no-new-privileges)
• Container config validation (injection prevention)
• Read-only rootfs option
• NetworkPolicy for Kubernetes deployments

Observability

• Structured JSON logging (BASCULE_LOG_FORMAT=json)
• Tracing spans on auth, session lifecycle, exec requests

Client: bascule-shell

Identity-aware login shell with TPM attestation:

./target/release/bascule-shell --info

╔═══════════════════════════════════════════════════════╗
║  Bascule Shell v0.1.0                                 ║
║  Principal:  tking                                     ║
║  Method:     ssh-key                                   ║
║  TPM:        available (6 PCRs verified)               ║
║  Platform:   sha256:e9b95f002f54222d...                ║
╚═══════════════════════════════════════════════════════╝

See docs/bascule-shell.md.

Comparison

	Bascule	Teleport	Boundary
License	Apache 2.0	AGPL / Commercial	MPL / Commercial
Agents required	No	Yes	Yes
Control plane	No	Required	Required
Container sessions	Yes	No	No
AI Agent Identity	Yes (Entra Agent ID)	No	No
Binary size	~7MB	~150MB	~100MB

See docs/comparison.md.

Deployment

• Standalone: cargo build --release -p bascule-server
• Docker: docker build -t bascule .
• Kubernetes: helm install bascule charts/bascule/ — see docs/kubernetes.md

Extending Bascule

Implement SessionHandler to add custom policy:

use bascule_core::hooks::{SessionHandler, SessionInfo};

struct AuditHandler;

#[async_trait]
impl SessionHandler for AuditHandler {
    async fn on_session_start(&self, s: &SessionInfo) -> anyhow::Result<()> {
        println!("{} connected from {}", s.principal, s.source_ip);
        Ok(())
    }
}

See docs/architecture.md.

Roadmap

Not yet implemented:

• OIDC authentication (Keycloak, Entra, Okta)
• K8s API exec backend runtime
• SPIFFE/SPIRE auth runtime
• OpenTelemetry OTLP exporter
• Prometheus metrics endpoint
• Session recording
• Per-session Pod isolation

Documentation

• Quick Start
• Configuration
• Authentication
• Architecture
• Observability
• Kubernetes
• bascule-shell
• Comparison
• Container Images
• Contributing

License

Apache 2.0