The browser-native agent harness

peerd runs general-purpose agents inside your own Chrome or Firefox.

It works with the tabs, signed-in sessions, web apps, and browser-contained compute you already have. You choose a supported cloud or local model provider. No Peerd account or hosted browser is required, and current builds send no product telemetry to Peerd.

Local agents can access your whole computer. Remote agents live in someone else's. peerd runs inside your browser.

Install · peerd.ai · Architecture · Security

Why browser-native

Your browser already has your applications, sessions, identity, networking, interface, and useful local compute. It also has boundaries built for hostile pages.

peerd uses those boundaries. Page work goes to separate actors with only the tools for that tab or environment. Credentials, network rules, confirmations, and audit stay with the extension. This defense-in-depth design assumes unsafe content will eventually get past a filter.

What makes peerd different

• Your browser is the workspace. The agent works with the tabs, apps, sessions, and page content already in front of you.
• Page work stays separate. Web, WebVM, Notebook, App, and preview dweb actors each get tools for their own environment.
• Site knowledge is reusable. The web actor can build an adaptive client for a site and use it again on later tasks.
• Compute stays in browser boundaries. peerd can run scripts, sealed JavaScript Notebooks, compiled WASI tools, browser Apps, and Linux WebVMs on Chromium.
• You choose the model. The live provider inventory is defined in registry.js, including BYOK cloud adapters and keyless local options.
• P2P is optional. Preview builds add signed identity, browser-to-browser discovery, dwapps, and agent-to-agent communication over WebRTC; store packages prune it entirely.

Status

peerd is an experimental 0.x beta. Breaking changes are likely. Storage formats and product behavior may change. It can drive browser pages and use API keys, so review the security model before using it with sensitive data.

Chromium is the primary product target. Firefox support is experimental. It runs actors in dedicated workers and uses visible Notebooks for JavaScript compute. Features that need Chrome's offscreen document host are removed from Firefox controls and model tools before use. The Firefox preview package also omits dweb until Firefox has a mesh host.

The code is the source of truth for current behavior. Start with CLAUDE.md, then read the relevant module under extension/.

What it does

• Runs an agent loop in Chrome and an experimental Firefox package.
• Reads and drives browser tabs through per-environment actors.
• Runs Linux WebVMs, JavaScript Notebooks, browser Apps, and, where the runtime host supports them, headless scripts.
• Supports cloud and local model providers. The live list is in extension/peerd-provider/registry.js.
• Stores provider secrets in a local encrypted vault.
• Includes an optional peer-to-peer dweb in preview builds.

Apps and WebVMs currently run on Chrome only. Apps have no ambient network access. Remote resources, fetches, WebRTC, forms, and external document navigation are blocked. External HTTP and HTTPS links require user confirmation.

Security model

peerd uses browser isolation, narrow tool exposure, service-worker policy gates, and explicit egress controls. The main agent delegates environment work to keyless actors. On Chrome and Firefox, non-orchestrator agent loops run in separate dedicated worker heaps. If the browser cannot prove that boundary, the actor request does not run and performs no work on its target.

Network behavior depends on the operation. Model calls, web reads, runtime asset loads, sandbox traffic, and preview dweb traffic use different scoped paths and policies. See SECURITY.md and the threat model for the current boundaries and known limitations.

Install

Chrome from source

1. Clone the repository.
2. Open chrome://extensions.
3. Enable Developer mode.
4. Choose Load unpacked and select the extension/ directory.

Reload the extension from chrome://extensions after source changes.

Firefox from source

Firefox needs a Firefox-specific package. Do not load the checked-in Chrome development manifest. Use a Firefox version at or above the minimum declared in the channel patch under manifests/. That floor tracks the document-bound scripting support used by browser tools.

bun run package -- --channel=preview --browser=firefox --no-sign

Open about:debugging#/runtime/this-firefox, choose Load Temporary Add-on, and select artifacts/peerd-preview-firefox.xpi. Temporary add-ons must be loaded again after Firefox restarts. Browser and channel transforms are defined by the packaging scripts.

Release packages

See GitHub Releases for current artifacts. Store and preview builds differ. Store builds omit the dweb. Preview builds include it and may enable additional automation features. The packaging code is the authority for each browser and channel.

First run

1. Open peerd from the browser toolbar.
2. Create and unlock the local vault. Passphrase unlock is always available. Passkey unlock depends on WebAuthn PRF support in the browser and device.
3. Complete the short profile onboarding.
4. Open Settings, then add a provider key or choose a supported local provider.
5. Select a model and start a chat.

Only vault secrets and protected security records are covered by the vault encryption boundary. Other local extension state follows the storage rules in the security documentation.

Architecture

The extension has five main modules. Each module exposes its public API through its index.js.

The extension chassis lives in background/, offscreen/, sidepanel/, engine-tabs/, permissions/, shared/, and related support directories.

Development

The shipped extension is vanilla JavaScript with ES modules and no bundling or transpilation. Bun is used for tests, generation, packaging, and release checks.

bun install
bun run gen:dev
bun test ./tests
bun scripts/cdp/run-inbrowser-tests.mjs
bun run typecheck
bun run lint
bun run e2e:verify
bun run preflight

There are three test surfaces:

• Bun tests for pure logic.
• In-browser tests for extension and browser integration.
• Live Chrome E2E and visual verification for complete flows.

For UI changes, run bun run e2e:verify, inspect scripts/cdp/artifacts/result.json, and inspect the generated screenshots.

Generated files must not be edited by hand. In particular, extension/manifest.json and extension/shared/channel-config.js come from the manifest and packaging sources. CI checks them for drift.

Read CONTRIBUTING.md before changing code.

Documentation

• CLAUDE.md: project structure, conventions, and current posture
• SECURITY.md: security policy and reporting
• docs/security/THREAT-MODEL.md: trust boundaries and residual risks
• docs/security/LIFECYCLE-CONTRACT.md: interruption behavior and recovery limits
• docs/security/RED-TEAM-RESULTS.md: red-team coverage
• docs/store/: store packaging, permissions, privacy, and reviewer notes
• scripts/cdp/GALLERY.md: E2E and visual states

Design records under docs/design/ are point-in-time proposals. They explain past decisions and planned work. They do not override current code.

Dependencies and license

Runtime dependencies are vendored under extension/vendor/. Their source, version, license, and integrity records live in the adjacent SOURCE.txt files and extension/vendor/vendor.lock.json.

peerd is licensed under the Apache License 2.0. Vendored components retain their own licenses. CheerpX is a proprietary runtime provided by Leaning Technologies and is not covered by peerd's Apache license.