RainDragon Forecast
Claude Code plugin · Chrome extension
How long will Claude take? Forecast tells you.
When you send a prompt, Forecast shows how long turns like it usually take you, as a range from your own past turns. A small clock runs while Claude works, and you get a storm warning when Claude has a major outage.
Illustration. The shaded range is where half of your similar past turns finished. The line is the turn in progress. If it goes past the range, the status line says "running long".
☊☋ are old astronomers' symbols for the Dragon's Head and Tail. Every Forecast line starts with them.
What you see
Two places, one idea
Claude Code
Shown when you send a prompt. On newer Claude Code versions, the status line also runs a live clock and clears when the turn ends.
claude.ai, ChatGPT and Gemini
Forecast 20s–1m · 300–800 words · 0:12A small bar just above the message box: how long the reply usually takes, how long it usually is, and a running clock.
How it works
A range, never a single number
Nobody can say exactly how long a turn will take: the same request can take 20 seconds one time and 2 minutes the next. So Forecast never guesses one number. It looks at your past turns that were like this one and shows the range the middle half of them fell in. "Forecast 40s–3m · half of your similar turns (57)" means half of your 57 similar turns took between 40 seconds and 3 minutes. If you prefer, switch to a wider range that holds about 8 in 10.
"Similar" means the same prompt size, conversation size and effort level, widening to broader groups until there are at least 8 turns to go on. Only your most recent 300 good turns are used.
It tells you when it doesn't know yet
| Your good turns | What it shows |
|---|---|
| 0–9 | "RainDragon Forecast is learning your pace. Ranges start after 10 turns." (once per session) |
| 10–29 | a wider range (8 in 10 of your similar turns), marked "still learning" |
| 30+ | the normal range (half of your similar turns), and one "Forecast has your pace" message |
- Bad turns don't stretch itFailed turns, turns you stop, and turns during a major Claude incident are left out.
- Storm warnings for big outages onlyIt checks status.claude.com and warns only for a major incident on Claude Code, the Claude API or claude.ai. In our measurements, turns ran 1.81x longer during major incidents and no longer during minor ones, so minor ones are not flagged.
- Check it yourself
/forecast:stats(or the extension's options page) shows how often your turns really finished inside the range, your typical turn and your longest.
The browser extension has less to go on than the plugin: it reads the page, not exact turn boundaries, and doesn't see the effort level.
Install
Get Forecast
Pick the one that matches how you use Claude. You can have both.
Chrome extension
Takes about two minutes. Forecast isn't in the Chrome Web Store yet, so you add it by hand. Here's how.
-
Download Forecast. You get a .zip file. Double-click it to unzip it, and remember where the folder is (usually Downloads).Download for Chrome
-
Open Chrome's extensions page. Click the address bar at the top of Chrome, type
chrome://extensionsand press Enter. -
Turn on Developer mode. The switch is in the top right corner of that page. It only lets you add extensions by hand. Chrome may remind you now and then that it's on. That's normal.
-
Click "Load unpacked" and choose the folder called
raindragon-forecast-extensionfrom step 1. If you see a folder with the same name inside it, choose the inner one: it is the one withmanifest.jsonin it. -
Done. Open claude.ai, chatgpt.com or gemini.google.com and start typing. The Forecast bar appears just above the message box.
For the first 10 replies it says it is learning your pace. That's expected: it learns from you. To remove Forecast, open chrome://extensions and click Remove under RainDragon Forecast.
Claude Code plugin
Needs Python 3, which most Mac and Linux computers already have.
Copy these two lines into your terminal:
That's it. Your next prompt starts the learning. Later, type /forecast:stats in Claude Code to see how well it's doing.
Had RainDragon ETA? Run claude plugin uninstall raindragon-eta@raindragon first. Your history comes with you automatically.
To remove Forecast: claude plugin uninstall forecast@raindragon.
For developers
Settings and diagnostics
Plugin settings: /plugin configure forecast@raindragon (on/off, range width, show actual time, status checks, mark). export RAINDRAGON_FORECAST_OFF=1 also turns it off. For a bug report, /forecast:doctor prints the version, settings and counts (no prompts, file names or session ids).
Check the download
Each release has a SHA256SUMS file. In the folder with the zips:
Every line must say OK. The zips are reproducible: python3 release.py on the tagged commit builds the same bytes.
Remove every file
After uninstalling the plugin, delete ~/.claude/plugins/data/forecast* and ~/.raindragon-forecast. Removing the extension in Chrome deletes its history with it.
Codex CLI and Gemini CLI
The same hook runs in the Codex CLI and Gemini CLI, each with its own separate history. These are newer and not yet checked live; see INSTALL_CLI.md and PROVIDERS.md.
Privacy
Your work stays on your computer
- For each turn it keeps how long it took, size buckets (short, medium, long), the effort level, and whether it failed or ran during an incident. Never your prompts, replies, file names or project paths.
- The one thing that leaves your computer is a request to the public status page, at most every two minutes. You can turn it off.
- Nothing is sent to RainDragon. No telemetry, analytics or crash reporting.
- If we ever add a way to share timing data, it will be off by default, opt-in, and show you exactly what would be sent before anything is.