Using Slipstream.

What Slipstream does

An AI coding agent re-sends a lot of the same context on every turn: files it already read, stack traces it already saw, logs, lock files, history. The model bills you for all of it, every request.

Slipstream sits in the middle as a local proxy. When your agent sends a request, it passes through Slipstream first, which removes the redundant parts before forwarding it to the model provider. The agent gets the same answer; the request is 60–95% smaller. The compression engine is headroom, an open-source (Apache 2.0) project; Slipstream is the desktop app that runs it with zero setup and shows you, in dollars, exactly what it saved.

• Runs entirely on your machine — no account, no cloud, no servers.
• Your agent keeps its own API keys and its own connection to the provider.
• Works with Claude Code, Codex, Cursor, Aider and GitHub Copilot, plus any other OpenAI-compatible tool.
• Free for 30 days, then a few dollars a month on the honor system.

1 · Install

Slipstream is a regular desktop app — download, open, done. Pick the build for your system. macOS 13+ and most current Linux distributions are supported. A signed Windows build is on the way.

On the download page you'll find macOS (Apple silicon) and macOS (Intel) .dmg files and a Linux .AppImage. Not sure which Mac you have? Apple menu → About This Mac: "Apple M1/M2/M3…" means Apple silicon, "Intel" means the Intel build.

macOS

1. Open the .dmg and drag Slipstream to Applications

   The standard install — drop the app icon onto the Applications folder shortcut.

2. Launch it from Applications

   Use Launchpad or Spotlight. The app lives in your menu bar, not the Dock.

Linux

1. Make the AppImage executable

   Either right-click → Properties → "Allow executing file as program," or in a terminal: chmod +x Slipstream_*.AppImage

2. Run it

   Double-click the AppImage, or run it from the terminal. It appears in your system tray.

2 · First launch

The very first time you open Slipstream, it sets up a private runtime for the compression engine. You'll see four short steps:

1. Downloading Python

   A self-contained Python — not your system one, and it never touches an existing install.

2. Creating a private environment

   An isolated folder that belongs only to Slipstream.

3. Installing headroom

   A pinned, known-good version of the compression engine.

4. Verifying everything works

   A quick self-check, then the app opens.

This takes about a minute on a cold machine and only happens once. It needs a network connection that first time, to fetch the runtime. After that, Slipstream runs offline — the only network traffic is your agent's own calls to its model provider.

3 · The menu-bar app

Slipstream lives in your menu bar (macOS) or system tray (Linux). Click the icon for a compact panel — the thing you'll glance at day to day:

• Status dot & switch — a colored dot shows whether the proxy is running, and the switch turns it on or off.
• Saved this month — the big number, in dollars, with a sparkline of the trend.
• Tokens saved — total tokens removed and how much smaller your requests got, as a percentage.
• Agent toggles — quick on/off switches for each connected agent, without opening the full window.
• Open Dashboard — opens the full window. Quit stops the proxy and closes the app.

If you're on the free trial, a small line near the top counts down the days left. When the trial ends it prompts you to subscribe.

4 · Starting the proxy

The proxy is the part that does the work. Nothing is compressed until it's running. Turn it on from the menu-bar switch, or from Start proxy on the dashboard. By default it listens at:

http://localhost:8787/v1

That's the address your tools point at. Most agents are wired up for you (next section); this URL is for anything you connect by hand. You can change the port in Settings → Proxy → Port if 8787 is taken.

To have it ready whenever you are, turn on Start proxy when Slipstream opens and Launch Slipstream at login in Settings. Then it's always there, quietly, and savings begin the moment you start coding.

5 · Connecting your agents

Open the full window and go to Agents. Slipstream detects the supported coding agents you have installed and lists them. Connecting one is called wrapping: Slipstream edits that agent's own config so its traffic flows through the proxy automatically.

• Agents with a switch — flip it on. That's the whole step.
• Agents with a "Snippet" button — these wrap per session. Click Snippet, copy the line, and use it where that tool reads its config or when you launch it.
• Anything else — any OpenAI-compatible tool works by pointing its base URL at the proxy (the http://localhost:8787/v1 address above).

Claude Code

Flip the toggle, then restart Claude Code. Wrapping Claude Code also installs a small startup hook that wakes the proxy when a session begins — so a freshly started session never points at a dead port, even if Slipstream wasn't open yet.

Codex, Cursor, Aider, GitHub Copilot

Same idea: flip the toggle in the Agents list (or copy the Snippet if that agent shows one instead), then restart the tool. Each row shows its current state — "Routing through Slipstream" once it's wrapped, "Not wrapped" when it isn't.

Any other OpenAI-compatible tool

Set the tool's API base URL (sometimes called "OpenAI base URL," "endpoint," or "OPENAI_BASE_URL") to the proxy address. Keep using your own provider API key as normal — Slipstream passes it straight through.

OPENAI_BASE_URL=http://localhost:8787/v1

6 · Reading the dashboard

The Overview is the home of the full window. Once your wrapped agents start making requests, the numbers fill in. Use the range switcher in the top-right — Today, 7d, 30d, All — to change the window everything is measured over.

The four headline numbers

Each card carries a small sparkline and a delta versus the previous period (for example, "↑ 18% vs previous"), so you can see whether savings are trending up.

The panels below

• Token savings over time — a bar per day, split into "saved" and "spent," so the shape of your usage is visible at a glance.
• Breakdown — where the dollars came from, split by source (rewriting context vs. provider prefix-cache) and by model.
• Recent activity — the latest agent sessions: which agent, which model, when, and how much each saved. It refreshes on its own.

When it looks empty

If the proxy is running but you haven't sent a request yet, the dashboard says it's listening and waiting — point a wrapped agent at it and the first numbers land here. If the proxy is stopped, you'll see a Start proxy button instead. Cost figures stay at zero until at least one request has gone through.

7 · Compression & settings

Everything is in Settings, and changes apply immediately — the proxy restarts itself when it needs to. No file editing, no JSON.

Compression mode

Two ways to balance raw savings against your provider's caching:

• Max savings — rewrites context aggressively for the biggest token reduction. The default, and usually the right choice.
• Cache friendly — freezes earlier turns so your provider's prefix cache keeps hitting. Pick this if your model bills cached input much cheaper and you want those cache hits preserved.

Command compression (RTK)

A second, optional engine. Where compression mode (above) shrinks the conversation Slipstream sends to the model, RTK shrinks the output of the shell commands your agent runs — git, npm test, grep and 100+ others — before that output ever reaches the model. It's bundled, so there's nothing to install. Read why we added it →

1. Flip “Trim command output (RTK)”

   Under Settings → Command compression. Slipstream wires RTK into Claude Code and puts the bundled rtk on your path. It's off by default.

2. Restart your agent

   The hook loads when a Claude Code session starts, so restart any running sessions for it to take effect. Turning it off and restarting removes it cleanly.

Semantic cache

When on, Slipstream answers repeated or near-identical requests locally instead of paying the model again — effectively free. Handy for agents that re-ask the same thing.

Daily budget

Set a dollar cap and Slipstream pauses upstream spend once you pass it for the day. Leave it empty for no limit. A safety net against a runaway agent loop.

Proxy

• Port — where tools connect. Change it only if something else already uses 8787.
• Start proxy when Slipstream opens — savings begin the moment the app is running.
• Launch Slipstream at login — it waits quietly in the menu bar.

Models & pricing

The Models card holds each model's context window and price (in USD per million tokens, input and output). The context window guides how aggressively context is compressed; the prices drive the dollar estimates on your dashboard. Add a model or adjust one when a provider changes pricing — risky edits ask you to confirm against a diff first, so you can't fat-finger your numbers.

Privacy toggle

Share anonymous usage stats controls whether headroom sends anonymous aggregate figures (tokens saved, app version, OS — never your code or prompts) to its public dashboard. It's on by default upstream; one click turns it off. See Privacy & your data.

8 · Shared memory

Memory lets your agents remember facts, preferences and project context across sessions — and across each other. Something Claude Code learns can be recalled by Cursor later. It's stored locally and off by default.

1. Turn on memory

   Open the Memory tab and click Turn on memory. Nothing is downloaded; it's all local.

2. Let your agents work

   Memories accumulate as agents run. Each entry shows its text, which agent saved it, which project (workspace) it came from, when, and an importance score.

3. Search and prune

   Use the search box to find a memory. If there's more than one memory space, a switcher lets you pick. To remove one, click the trash icon, then Forget? to confirm.

9 · MCP tools

Beyond the proxy, headroom ships an MCP server — a set of tools your agent can call directly: compress, retrieve and stats. Slipstream installs it for you. On the Agents tab, find the MCP tools card and click Install next to a client (such as Claude Desktop or Claude Code).

• Tools become available the next time that agent restarts.
• It works even while the proxy is off — the MCP server is independent.
• Click Remove to uninstall. If a client was set up outside Slipstream, manage it there.

10 · Privacy & your data

Slipstream is a local proxy on your own laptop. Requests go agent → localhost → your model provider. Nothing is routed through our servers, because there are no servers.

• No account, no sign-in, no cloud.
• Your agent keeps its own API keys and its own provider connection.
• Stats and memory live in a local database, yours to delete.
• Anonymous usage stats are surfaced honestly and are one click to disable.
• The compression core is open source, Apache 2.0.

To see exactly where things are kept, open Settings → Storage. Each row — Headroom data, Slipstream data, and the proxy log — has a Reveal button that opens the folder in your file manager.

11 · Your free month & plans

Slipstream is free for 30 days with everything included — no card, no account. The trial starts the moment you install. The menu-bar panel and Settings → License both show how many days are left.

After the trial, pick the plan that matches your AI spend. It's an honor system — every plan unlocks the same full app:

1. Pick a plan

   In Settings → License, choose the tier that fits and complete checkout in your browser.

2. Paste your key

   Your license key (it starts with SLIP-) arrives right after checkout. Paste it into the License field and click Activate.

12 · Updates

Slipstream updates itself. To check on demand, open Settings → About and click Check for updates. If one's available it downloads, verifies, installs, and relaunches the app. The same card shows your current app version and the bundled headroom version.

13 · Troubleshooting

14 · Reference

At a glance

Status colors

Still stuck, or hit something this guide doesn't cover? The compression engine and its issues live on GitHub, and the homepage has a shorter FAQ.