1 screenshot = 200 words you didn't type
Claude Code, Aider, Codex CLI read your files, run your tests, write your code. But the moment you want to talk about the UI, you're writing a paragraph to describe what a screenshot would show in a glance. And terminals don't accept images.
SlimSnap closes the gap. Capture, annotate, copy as JSON. Paste it where text goes which is everywhere.
Capture
Hit ⌘⇧S, drag to select any area, release. ⌘⇧L captures a whole scrolling page. Native macOS, nothing to install.
Annotate
Arrows, callouts, highlights. Point at the broken thing.
Copy JSON
One click. Paste into Claude Code, Aider, or anywhere text goes.
Vision for tools that can't see images
A screenshot says a thousand pixels. SlimSnap says exactly what's on the screen: every element, its text, its position.
Annotations carry intent
An arrow or callout isn't just red pixels. It exports as structured intent pointing at a specific element, so the agent fixes the thing you marked instead of guessing what you meant.
Pastes into any agent
Claude Code, Aider, Codex CLI, Cursor, Continue.dev. Text goes everywhere images can't: terminals, SSH sessions, CI logs, git commits. If it takes text, it takes SlimSnap.
Deterministic layout
Every element has a bounding box in normalized 0 to 1 coordinates. Your agent stops guessing where things are.
OCR baked in
Built-in OCR reads every label, button, and error message in the shot. Your agent sees the words you see.
Whole pages too
Press ⌘⇧L for scrolling capture: scroll yourself or let Autoscroll drive. Long pages split into readable frames with one JSON over the whole capture, because AI tools can't read one very tall image.
Stays on your Mac
Capture and OCR run locally. No upload, no account, no server in the loop. Your screens never leave the machine.
Open MIT format
The JSON schema is published on GitHub under MIT. Read it, validate against it, or write your own exporter. View the schema
signup.jsonthe whole screen, readable by any agent
{
"schema_version": "2.0",
"captured_at": "2026-07-11T18:17:46Z",
"mode": "single",
"capture": { "width_px": 1440, "height_px": 900 },
"screen": { "title": "Create your account", "app": "Safari" },
"frames": [
{
"index": 0, "kind": "spatial",
"dims": { "width_px": 1440, "height_px": 900 },
"position": { "scroll_y_px": 0 },
"elements": [
{ "id": "e1", "type": "label", "value": "Create your account",
"bbox": [0.34, 0.18, 0.32, 0.06] },
{ "id": "e2", "type": "input", "value": "Email",
"bbox": [0.34, 0.34, 0.32, 0.07] },
{ "id": "e3", "type": "input", "value": "Password",
"bbox": [0.34, 0.46, 0.32, 0.07] },
{ "id": "e4", "type": "button", "value": "Sign up",
"bbox": [0.34, 0.60, 0.32, 0.07], "color": "#3B82F6" }
],
"annotations": [
{ "id": "a1", "type": "arrow", "to": [0.67, 0.62],
"target_ref": "e4", "intent": "highlight" }
]
}
],
"estimated_tokens": 318
}Questions
Why not just paste a screenshot into ChatGPT?
You can, and you should, for one-off questions. But terminal agents (Claude Code, Aider, Codex CLI) don't accept images. SlimSnap solves that. It is also far more reliable when the agent needs to reason about specific elements rather than vibes.
Does it send my screenshots to a server?
No. OCR runs locally on your Mac. Captures never leave your machine.
How does the Claude Code skill find my captures?
SlimSnap writes a tiny config file at ~/.slimsnap/config.json on startup and every settings change. It contains your default save folder and filename pattern, nothing else. The skill reads that config, lists the folder, and loads the latest JSON file into the agent's context. No hardcoded paths. If you change where SlimSnap saves, the skill follows. Full walkthrough: The Claude Code skill that turns a screenshot into a fix.
Do I need the Mac app to use the skill?
No. The skill works on any valid SlimSnap JSON file. The Mac app is the easiest way to produce one, but the schema is open MIT so you can hand-write JSON, generate it from another OCR pipeline, or build your own exporter on Windows or Linux. The skill doesn't care where the JSON came from.
Does the JSON lose information compared to the raw image?
For element-level work it wins. The JSON carries the text, position, color, and bounding box of every element, which is exactly what an agent needs to change a specific thing. What it drops is pixel aesthetics: gradient direction, whitespace feel, brand vibe. So for "fix this specific element" loops, JSON is more reliable. For "what should this look like" exploration, paste the raw image. Nothing stops you sending both.
Can it capture a whole page, not just what's on screen?
Yes. Press ⌘⇧L, select the area, and scroll through the content. Or press Autoscroll and SlimSnap scrolls the page for you: any click stops it. Long captures are split into page-sized frames rather than one tall image, because AI tools downscale very tall screenshots until the text is unreadable. You get each frame as its own image plus one JSON that covers the whole page in order.
Isn't cropping the screenshot tightly enough?
A crop is still pixels the agent has to interpret. SlimSnap hands over the actual text, elements, and coordinates, so the agent reasons about "the second input in the third card" instead of guessing from a picture.
Does it work on dark mode UI?
Yes. OCR and element detection behave the same in dark mode as in light. Very low-contrast themes are the one edge case worth a sanity check, but dark interfaces like terminals, Slack, and Linear are handled the same way.
Not on Mac?
SlimSnap is Mac-only today. Want it on Windows or Linux? Email hi@slimsnap.ai and tell us which. The more requests we get, the sooner we build it.
