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Relational consistency engine
Every fingerprint surface — canvas, WebGL, audio, fonts, MediaDevices, WebGPU — derives from a single (profile, seed) pair through a 48-rule DAG. No Frankenstein fingerprints; a Mac UA never lands next to Linux WebGL.
Bun-native · MIT · stock Chromium
Sticky on the outside.
Untouchable on the inside.
mochi.js is a Bun-native, raw-CDP browser automation framework. Pass a seed and a profile; get a relationally-coherent fingerprint that survives a getParameter(0x9245) probe. JIT-friendly inject payload, Chromium-native fetch (real Chrome JA4 by definition), behavioral synth on top of Bezier+Fitts. Leaves no crumbs.
bun ≥ 1.1 macOS · Linux · Windows MIT
five pillars
Built for the strictest probes.
Where Playwright and Puppeteer leave fingerprints, mochi.js leaves nothing measurable. Each pillar covers one class of detection.
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Chromium-native fetch
session.fetch() routes through Chromium itself via CDP — Network.loadNetworkResource for simple GETs, page.evaluate('fetch') for non-GET. JA4/JA3/H2 are real Chrome by definition. No parallel HTTP layer to keep in lockstep, no FFI to install.
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Behavioral synthesis
humanClick / humanType / humanScroll synthesize from biomechanical models — Bezier paths with overshoot+correction, Fitts-law movement times, lognormal digraph delays. Profile-parameterized: hand, tremor, wpm, scrollStyle.
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Probe-Manifest harness
Captured baselines from real devices live in the repo. Every PR diffs the live session's Probe Manifest against the baseline; Zero-Diff is a CI gate. Intentional divergences live next to a written rationale.
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One coherent stack
Replaces the usual hand-stitched pipeline (Patchright + fingerprint-injector + Turnstile clicker + curl-impersonate) with one library that owns it end-to-end. Bun-only. No Node, no Python sidecars, no proprietary bits.
three-line stealth
Same Playwright muscle memory.
None of the crumbs.
import { mochi } from "@mochi.js/core";
// boot a stealth browser in three lines
const session = await mochi.launch({
profile: "linux-chrome-stable",
seed: "user-12345",
});
const page = await session.newPage();
await page.goto("https://target.example/checkout");
console.log("UA:", session.profile.userAgent);
await session.close();