apache-2.0 open source

Stop routing sensitive data through third-party gateways.

Outband is a 12MB sidecar that generates SOC 2 evidence from every LLM API call — inside your VPC, with sub-millisecond overhead. No Redis. No external databases. No control plane.

terminal
# One env var. That's it. $ export OPENAI_API_BASE=http://localhost:8080/v1 # Start the sidecar $ outband --target https://api.openai.com telemetry output: file (JSONL) audit pipeline enabled: pool=50MB, workers=8 proxying localhost:8080 -> api.openai.com # Your app runs unchanged. Outband audits everything.
p99 overhead <1ms

SaaS gateways add latency, expand your attack surface, and give you alterable logs.

SaaS Gateway
Your App Internet Gateway SaaS Internet LLM API
  • 50–100ms added latency per request
  • Unredacted prompts transit third-party infrastructure
  • Requires Redis, blob storage, load balancers for self-hosted
  • Logs stored in external database — alterable, deletable
Outband Sidecar
Your App Outband LLM API
  • <1ms overhead — localhost, no network hop
  • All data stays inside your VPC
  • 12MB binary — no Redis, no external databases
  • SHA-256 hash chains — cryptographically immutable evidence

Three structural advantages gateways cannot replicate

No network hop

The sidecar runs on localhost. Your request never leaves the machine before hitting the upstream API. No DNS resolution, no TLS handshake to a gateway, no routing through a third party's load balancer. The hot path is a single io.Read wrapper.

0
p99 proxy overhead *

Zero phone home

No telemetry sent to us. No external database. No license server for the free tier. The only outbound connection is to your configured LLM API. If our company disappears tomorrow, your sidecar keeps running.

0
sent to Outband infrastructure

Proof, not logs

Gateways give you database rows. Outband gives you SHA-256 hash chains with timestamp binding, mapped to SOC 2 CC6.1, CC6.6, CC9.2 and ISO 42001. An auditor can verify the chain independently. Nobody — including you — can alter the evidence after the fact.

0
per request — original + redacted

* Benchmarked on Apple M2, Go 1.26.1, local httptest.Server isolating proxy overhead from network variance. Full benchmark data.

docker compose up — try it in 2 minutes

A DevOps engineer can deploy and understand the entire system in an afternoon.

0
Static Go binary
0
External dependencies at runtime
0
Environment variable to configure
0
Lines of Kubernetes YAML

A DevOps engineer can read the entire source, deploy it, and hand the first evidence summary to compliance — all before lunch.

What it actually takes to run each approach

Outband AI Gateway (SaaS) AI Gateway (Self-hosted) DIY Logging
Network egress required No Yes — all traffic Depends on config No
External databases None Vendor-managed Redis + blob storage You build it
Binary / deployment size 12MB static binary N/A (hosted) Helm chart + dependencies Varies
Latency overhead <1ms (localhost) 50–100ms (network hop) 10–30ms (in-VPC) ~0 (in-process)
Cryptographic audit trail SHA-256 hash chains Database rows Database rows None
SOC 2 evidence mapping CC6.1, CC6.6, CC9.2 Varies Varies Manual
Data sovereignty Your VPC only Third-party infra Your VPC Your VPC

You're routing LLM traffic through this. Here's why that's safe.

The sidecar runs in your trust boundary, not ours. We built it to be auditable.

Same trust boundary

The sidecar has access to the same data your application already handles. It does not expand your attack surface. Full threat model.

Fully auditable source

Apache 2.0. CI runs go test -race on every commit. No obfuscation, no binary blobs. Read the source.

Fail-open design

If the audit pipeline is under load, the proxy continues forwarding. Drops are counted in every evidence summary. Security policy.

Responsible disclosure

Security issues: security@outband.io. 48-hour acknowledgment. 7-day assessment. Coordinated disclosure.

Open core, custom enterprise

The open source tier is the full audit pipeline, not a trial. Enterprise pricing scales to your environment.

Open Source
Free
Apache 2.0 — forever
  • Request-side PII auditing
  • JSONL telemetry (file or stdout)
  • JSON evidence summaries
  • Webhook delivery
  • Prometheus metrics
  • Kubernetes-native stdout mode
  • Community support via GitHub
View on GitHub

Future features labeled honestly. The free tier is not a trial.

Continuous Compliance Evidence for Generative AI

An architectural approach to SOC 2 and ISO 42001 in LLM-powered applications. Covers the sidecar architecture, evidence schema, control mapping, and deployment model.

Read Whitepaper

Contact

Talk to us

Questions about enterprise features, deployment, or compliance requirements? We respond within 24 hours.

contact@outband.io
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