Context meter

In plain words

A little ring that fills up as a chat with an AI gets longer, like a fuel gauge.

ui.context_meter(used, limit) shows how full an AI model’s context window is: a small ring and 48k / 200k. It is gray below 80%, yellow from 80% and red from 95%, and its tooltip gives the exact counts. ui.format_tokens(count) writes a count the short way: 950, 4.5k, 48k, 1.25M.

ui.context_meter · Category: AI agents · Full reference →

Preview

Code

pz.row([
    ui.context_meter(48_000, 200_000),
    ui.context_meter(170_000, 200_000),
    ui.context_meter(196_000, 200_000),
], spacing=24, align="center")

New

This component was added recently. Tell us how it works for you in the issue tracker.

When to use

• In the toolbar or the input box of an agent’s chat, so the user sees when a conversation gets long.

Usage

import pyzed as pz
from pyzed import ui

pz.row([
    ui.context_meter(48_000, 200_000),
    ui.context_meter(170_000, 200_000),
    ui.context_meter(196_000, 200_000),
], spacing=24, align="center")

Variants

About these captures

Each capture is recorded by pyzed itself, off-screen at 2x, in One Dark or One Light to match this site’s theme, and cropped to the component so it shows at its real size. The pointer hovers, presses or types into it; a component that does not react to the pointer cycles through a few themes. With reduced motion you see the first frame. Open Code under a capture to see the snippet that draws it; free names such as on_save stand for your own callbacks.

Level

Drawn as the pointer shows it: tooltips only open on hover.

Below 80%

Code

ui.context_meter(48_000, 200_000)

From 80%

Code

ui.context_meter(170_000, 200_000)

From 95%

Code

ui.context_meter(196_000, 200_000)

Tooltip

Code

ui.context_meter(48_000, 200_000)

Short counts

ui.format_tokens returns the text the meter shows, for your own labels.

format_tokens(950)

Code

ui.label(ui.format_tokens(950), mono=True)

format_tokens(4_500)

Code

ui.label(ui.format_tokens(4_500), mono=True)

format_tokens(48_000)

Code

ui.label(ui.format_tokens(48_000), mono=True)

format_tokens(1_250_000)

Code

ui.label(ui.format_tokens(1_250_000), mono=True)

Events

Context meter has no events of its own: it shows what you give it. Like every widget it also has the 18 common events (click, double_click, right_click, mouse_enter, drag, key_down, resize…), attached with .on(...): see Events and Events of every component.

Properties and API

ui.context_meter

context_meter(used, limit, *, theme=None)

How full a model’s context window is, like Zed’s token counter: a small ring and 48k / 200k, yellow past 80% and red past 95%.

Property	Default	Description
used	required	Tokens in use.
limit	required	The model’s window.
theme	None	Theme.

Full reference →

ui.format_tokens

format_tokens(count)

A short token count: 950, 4.5k, 48k, 1.25M.

Property	Default	Description
count	required	Tokens.

Full reference →

Related

DonutA donut chart with a label in the middle.

ProgressA thin progress bar in a semantic color.

Tool callOne step of an AI agent: what it did, its result, and Allow or Reject.