What is E2B's primary brand color?

E2B's brand voltage is highlighter-orange `#ff8800` — wired in CSS as `--color--brand`. It appears 77 times in the captured page, used almost exclusively as a horizontal marker-bar fill painted behind keywords in headlines ('DEEP RESEARCH AGENTS', 'AI AGENTS', 'A FEW LINES'). The treatment reads as a literal yellow-highlighter swipe across a printed page — a single chromatic moment repeated across the editorial bands. There is no second brand color in the system; the model-vendor accents (cobalt OpenAI orangered, gemini violet, anthropic coral, meta cobalt, mistral amber) are reserved exclusively for vendor logos and integration callouts, not brand chrome.

What typeface does E2B use, and what should I use as a substitute?

E2B runs IBM Plex Mono everywhere — display, heading, body, button, nav link, section divider, all in uppercase with tight tracking. The page declares three explicit weight families: `--mono-400`, `--mono-500`, `--mono-700`. Hero h1 sits at 64px IBM Plex Mono 700 with -0.32px tracking; section h2 at 60px / 700 with -0.8px tracking; labels at 12px / 400 with normal tracking, uppercase. A small IBM Plex Sans tier handles testimonial body copy at 14-16px. IBM Plex Mono is open-source (SIL OFL) so no substitute is needed; if you need a tighter alternative, JetBrains Mono or Berkeley Mono carry similar proportions.

Why does E2B paint a yellow bar behind keywords in headlines?

The yellow highlighter-bar is the system's signature chromatic move. Inside the hero h1 'AI SANDBOXES FOR DEEP RESEARCH AGENTS,' the phrase 'DEEP RESEARCH AGENTS' sits with an orange-yellow rectangle painted behind it as if a real highlighter marker had swiped across the page. The treatment repeats below the fold inside the h2 'BUILT FOR AI AGENTS, LLM TRAINING, AND MCPS' (where 'AI AGENTS' carries the same marker bar) and inside the 'IN YOUR CODE WITH A FEW LINES' h3 (where 'A FEW LINES' carries it). The convention reads as a printed-pamphlet handprint and reinforces the all-mono uppercase voice — a yellow marker across a typewritten page.

Why does E2B use rectangular buttons with zero corner radius?

The primary CTA 'START FOR FREE' is a true rectangle — ink-black fill, white IBM Plex Mono 500 uppercase text, zero corner radius. The choice is deliberate and consistent across the system: every button, every chip, every tab uses 0px corners except for the small handful of icon avatars that use a 64px container radius. The treatment reinforces the printed-pamphlet aesthetic; rounded corners would soften the chrome and read as a generic SaaS marketing page. Compare to Cloudflare's full-pill CTAs or Daytona's 57px pseudo-pill — E2B sits at the opposite end of the radius spectrum.

Can I use this DESIGN.md to build my own React agent-platform marketing site?

Yes — the file is designed to be fed into Claude, Cursor, or any AI tool that reads structured design tokens. The agent will reproduce E2B's specific moves: all-mono uppercase voice, yellow highlighter-bar accent painted behind keywords, zero-radius rectangular CTAs instead of pills, ASCII-style framed product cards with terminal-corner brackets, and the model-vendor accent palette scoped to vendor callouts only. The tokens resolve cleanly. The all-mono commitment is the move to borrow with care — it only works if your audience is comfortable with monospace as a primary reading voice; for general-audience products it would feel like a constrained typewriter pastiche.

E2B Design System

E2B's marketing system runs IBM Plex Mono everywhere — uppercase headlines, mono nav links, zero-radius rectangular CTAs, yellow highlighter accents.

About E2B DESIGN.md

Curated by Dov AzencotUpdated May 18, 2026Source e2b.dev

AI & LLM Platforms
Developer Tools & IDEs

E2B's marketing site does the move most agent-infrastructure brands won't commit to: it renders the entire page in IBM Plex Mono with uppercase headlines, uppercase labels, uppercase CTAs, and zero-radius rectangular buttons. The hero h1 "AI SANDBOXES FOR DEEP RESEARCH AGENTS" sits at 64px IBM Plex Mono 700 in ink-black, with the words "DEEP RESEARCH AGENTS" painted in a yellow highlighter-marker bar — like someone swiped a real marker across the printout. The primary CTA "START FOR FREE" is a black rectangle (zero corner radius) with white mono text. Where Daytona pairs Inter display with Berkeley Mono labels and Vercel commits to Geist Sans on matte black, E2B commits to all-mono on near-white with the yellow highlighter as the single chromatic move.

The DESIGN.md file packages the system into a machine-readable spec for React and AI tools. Inside: 18 color tokens — ink-black canvas-text, off-white canvas, the highlighter-yellow brand voltage, four gray text tiers, a constellation of model-vendor accent colors (cobalt OpenAI orangered, gemini violet, anthropic coral, meta cobalt, mistral amber) wired into CSS as `--color--accent-*` properties, plus a single mode-inverted near-black for the dark code-snippet panel. 17 typography tokens span IBM Plex Mono at three explicit weight families (400, 500, 700) across display, heading, body, label, button, and divider tiers — plus a small IBM Plex Sans tier for testimonial body copy. 4 radius tokens centered on 0px (the rectangular CTA) with one 64px outer-corner radius for hero containers.

Feed this file to Claude or Cursor and it reproduces E2B's specific moves: all-mono uppercase voice, yellow highlighter-bar accent painted behind keywords, zero-radius rectangular CTAs instead of pills, ASCII-style framed product cards, and the model-vendor accent palette wired as `--color--accent-openai`, `--color--accent-gemini`, `--color--accent-anthropic`, `--color--accent-meta`, `--color--accent-mistral`. The one move worth borrowing only if your audience is technical: the highlighter-bar treatment behind keywords. Most teams should reserve color highlights for inline `<mark>` tags inside body copy; E2B pushes the convention up into the hero h1 itself and the restraint of using only one highlighter color is what keeps it from feeling decorative.

What makes it distinct

All-mono brand voiceIBM Plex Mono carries every display, every nav link, every body paragraph, every button label and every section divider in uppercase with tight -0.32px tracking
Yellow highlighter-bar accent`#ff8800` orange-yellow paints behind keywords in headlines like a literal marker swipe, the single chromatic move on the page
Zero-radius rectangular CTAsthe primary 'START FOR FREE' button uses a 0px corner radius with ink-black fill and white mono text, no pill or pseudo-pill softening
ASCII-framed product cardssix cards below the fold sit in hairline boxes with terminal-style corner brackets and uppercase mono labels
Terminal-pamphlet rhythmthe page reads more like a printed-output zine than a SaaS marketing site; the only sans-serif on the page is the IBM Plex Sans body inside testimonial cards

Live at e2b.dev

A snapshot of the brand in production. Hover the frame to scroll the page; click to visit.

e2b.dev

Explore E2B

Pick what you want to see — mockups, colors, typography, layout, or the full component list.

Brand & Accent

Sparing, CTA-only voltage.

Surface

Page and card backgrounds.

Text

Headlines, body, captions, muted.

Borders & Hairlines

Dividers, outlines, structural rules.

Other

Specialty colors.

E2B design system FAQ

Common questions about E2B's tokens, components, and how to use this DESIGN.md in your project.

Specs, directories, and component libraries that pair with this design system.

Browse all design systems

The full directory of DESIGN.md files on shadcn.io, with live mockups for each.

E2B — official site

E2B's public marketing site — the source of truth for the live tokens captured in this file.

The DESIGN.md specification

Google Labs' open spec for machine-readable design system files — the format this page is built on.