Why not just use print() or logging?

Logging shows fragments. Tether connects the prompt, action, file diff, command output, failed test, and recovery point in one local execution graph.

Can I use this with production code?

Yes. It's a local proxy, so your real code doesn't change. Use it locally for debugging, or keep it running. Tether only stores traces locally and never sends anything anywhere.

How much money does caching actually save?

It depends on your agent. If you're iterating on prompt logic and re-running the same retrieval steps, caching saves you 50-90% of API spend while you debug. Each cached hit costs $0.0000.

Does Tether add latency to my agent?

Negligible. Tether runs locally on your machine. The only overhead is the proxy hop, which is less than 1ms. Real LLM calls are the bottleneck, not Tether.

Can I share traces with my team?

Not yet. Each developer runs their own Tether instance locally. Export as JSON is coming in a later release.

How does Tether intercept LLM calls without SDK changes?

Tether runs a local HTTP proxy on your machine. You point your AI client's base_url at http://localhost:8080/v1 — that's the only change required. Tether forwards requests to the real provider and records everything locally.

Does Tether send my prompts or API keys to the cloud?

No. Tether is fully air-gapped. Your prompts and responses stay on your machine. macOS secrets use Keychain-aware storage, Linux uses the same local proxy model, and traces stay local.

Which LLM providers does Tether support?

Tether supports OpenAI, Anthropic, Ollama, LM Studio, and any provider that accepts an OpenAI-compatible base_url. It also works with LangChain, LangGraph, LlamaIndex, and similar frameworks.

Yes. Tether is free during the alpha period. The core proxy is open source.

Home/Docs/Tether documentation

Docs

Tether documentation

Install Tether on macOS or Linux, capture local agent runs, inspect execution steps, recover failed branches, and understand the architecture behind the desktop clients.

Install Setup steps

Release: Alpha channel
Runtime: macOS + Linux + local proxy
Docs: 19 guides

What Tether does

Tether is a local-first execution debugger for agent builders. It runs a Rust proxy on the developer machine, stores captured execution traces in SQLite, and renders the run inside desktop clients for macOS and Linux.

Capture supported agent CLIs, LangChain, LangGraph, OpenAI/OpenGPT-style, and custom local runs through adapters or proxy ingestion.
Inspect prompt, action, command output, file changes, latency, tokens, cost, cache state, and errors.
Replay supported proxy-captured requests or use local rollback evidence when replay is unavailable.
Keep API keys and trace data on the local machine through platform-local storage paths.

Architecture pages

System overviewThe capture wrapper, desktop clients, Rust proxy, SQLite stores, provider upstreams, and release pipeline in one map.Open guide Execution graphWhy the graph is an agent execution graph, not an LLM request tree.Open guide Rust proxyGateway, cache, trace capture, replay, auth, settings, and OpenAPI boundaries.Open guide macOS appSwift package modules, graph panes, inspector panes, settings, and local source ingestion.Open guide CI/CD and releasesThe quality gates, tag-driven DMG release workflow, and local preflight commands.Open guide