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Anchor

plinklabs.org

From €24/mo Free plan Open source WebWindowsAPISelf-hostedBrowser extension
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Spec score 9.5 #1 of 25 in Classroom Management Software

What it is

Anchor is classroom software for schools using managed or bring-your-own-device Windows laptops. A teacher starts a focus session for a class, selects allowed app and website bundles, and watches student states and off-list events on a dashboard. Microsoft 365, Smartschool, and GeoGebra are named selectable bundles, and teachers sign in with existing school Microsoft accounts. Off-list apps are set aside rather than closed; off-list Microsoft Edge pages show a block page with an access-request option. Anchor provides activity monitoring, web filtering, and device controls, but no live screen view or behavior tracking. It observes activity only during an active teacher-started session. During that session, the extension sends off-allowlist visits, unblock requests, integrity signals, and liveness heartbeats to the school backend. Each school runs a single-tenant backend in its own Azure subscription. Anchor is GPL-3.0 licensed, self-hostable, and publicly auditable. It is free, with no licence fee or per-seat charge, though Azure hosting costs may apply.

Spec sheet

What it does
Anchor lets a teacher run a timed classroom focus session whose app and website allowlist is enforced on student devices while off-list activity appears live on a dashboard.Read 15 Oct 2026 · plinklabs.org
Purpose
Anchor lets a teacher run a classroom focus session where student Windows laptops enforce an allowlist of apps and websites, with off-list activity shown live on a dashboard.Read 4 Oct 2026 · plinklabs.org
Audience
The maker describes Anchor as classroom software made by teachers for schools using managed or bring-your-own-device Windows laptops.Read 4 Oct 2026 · plinklabs.org
Platforms
Student enforcement requires Windows 10 version 1809 or later, or Windows 11, together with Microsoft Edge; the teacher dashboard runs in a modern browser.Read 4 Oct 2026 · plinklabs.org
Integrations
The teacher page names Microsoft 365, Smartschool, and GeoGebra as selectable bundles; sign-in uses existing school Microsoft accounts.Read 4 Oct 2026 · plinklabs.org
Support
The maker directs users to GitHub issues for product questions and says there is no support ticket queue.Read 4 Oct 2026 · plinklabs.org
Agent stack
The student client is a WinUI 3 and C# application using Velopack for updates.Read 15 Oct 2026 · github.com
Allowlist bundles
Teachers choose named bundles such as Microsoft 365, Smartschool and GeoGebra instead of entering raw domains.Read 15 Oct 2026 · plinklabs.org
API architecture
The repository describes an ASP.NET Core REST API with Entity Framework Core, SignalR and Microsoft Entra authentication.Read 15 Oct 2026 · github.com
App enforcement
The Windows agent moves off-allowlist applications into the background and displays a gentle overlay without closing the applications.Read 15 Oct 2026 · plinklabs.org
Authentication
The deployment creates single-tenant Microsoft Entra registrations for the API and dashboard, with school accounts used instead of separate Anchor passwords.Read 15 Oct 2026 · plinklabs.org
Class management
Classes can be created manually, imported from CSV or populated from a school directory and reused for later sessions.Read 15 Oct 2026 · plinklabs.org
Dashboard stack
The teacher dashboard is implemented as Flutter Web with MSAL.js and is intended for Azure Static Web Apps.Read 15 Oct 2026 · github.com
Data collection
During an active session the system can send off-list URL details, unblock requests, integrity signals and liveness heartbeats; it does not record keystrokes, screenshots, passwords or allowlisted browsing.Read 15 Oct 2026 · plinklabs.org
Deployment defect
A GitHub issue documented backend deployment failures caused by a missing Azure publish-profile secret in the CI workflow.Read 15 Oct 2026 · github.com
Developer prerequisites
Local development documentation lists .NET 10 SDK, Node.js LTS, Flutter, Azure CLI and a controllable Entra tenant as prerequisites for the relevant components.Read 15 Oct 2026 · github.com
Documented defect
A GitHub issue reported that the foreground watcher failed to deliver Windows foreground callbacks, allowing off-list applications to remain usable during real sessions.Read 15 Oct 2026 · github.com
Extension stack
The browser component is a TypeScript Edge Chromium Manifest V3 extension.Read 15 Oct 2026 · github.com
Hosting
Each school runs a single-tenant backend in its own Azure subscription, and student devices and the dashboard communicate only with that backend.Read 4 Oct 2026 · plinklabs.org
Installation
The student agent is a per-user Setup.exe that needs no administrator rights, starts at Windows sign-in and updates itself; Edge receives the extension through policy.Read 15 Oct 2026 · plinklabs.org
Integrity witness
A native-messaging witness lets the agent and extension report if the other component is disabled during a session.Read 15 Oct 2026 · plinklabs.org
Licence
Anchor is released under the GPL-3.0 licence and is self-hostable.Read 15 Oct 2026 · plinklabs.org
License and auditability
Anchor is GPL-3.0 licensed, self-hostable, and its source code is public and auditable.Read 4 Oct 2026 · plinklabs.org
Limitations
Anchor is deliberately soft enforcement: the maker says a determined student can bypass it, with tampering surfaced as an integrity signal.Read 4 Oct 2026 · plinklabs.org
Live visibility
The teacher dashboard shows student state, joins, blocked pages and access requests as they occur during the lesson.Read 15 Oct 2026 · plinklabs.org
Local development
The backend can run locally with SQLite, the dashboard with Flutter on port 5173, and the extension through npm build and Edge unpacked-extension loading.Read 15 Oct 2026 · github.com
Maintainer size
The design document describes the project as being built by one developer in evenings and weekends.Read 15 Oct 2026 · github.com
Maker location
Plink Labs describes itself as built in Belgium.Read 15 Oct 2026 · plinklabs.org
Notable policy date
The Anchor privacy policy was last updated on 15 June 2026.Read 15 Oct 2026 · plinklabs.org
Platform limits
The maker says there is no student agent for Mac, Chromebook, iPad, or phone, and other browsers are outside the student-device scope.Read 4 Oct 2026 · plinklabs.org
Project maturity
The repository labels the backend, dashboard and agent as scaffolded and says later work remains for agent authentication, SignalR listening, foreground hooks and packaging.Read 15 Oct 2026 · github.com
Rating on G2
4.7 out of 5 from 30 reviews, but the opened G2 profile is for Anchor FM podcast hosting rather than Plink Labs classroom Anchor.Read 15 Oct 2026 · g2.com
Release history
The repository releases page lists agent versions from v0.1.0 through v0.2.0, with v0.2.0 released on 1 July 2026.Read 15 Oct 2026 · github.com
Retention
The school controls retention; the FAQ describes a default that prunes raw session events after 30 days while keeping summaries.Read 15 Oct 2026 · plinklabs.org
Security and privacy
Anchor observes only during an active teacher-started session and does not record on-allowlist work, keystrokes, page contents, screenshots, passwords, or browsing outside sessions.Read 4 Oct 2026 · plinklabs.org
Security transport
Client connections use outbound HTTPS/TLS with WebSocket upgrades to the school's App Service and Microsoft Entra sign-in, without TLS interception or proxy certificates.Read 15 Oct 2026 · plinklabs.org
Self-hosting
Each school runs its own backend in its own Azure subscription, and Plink Labs says it operates no backend and receives no student data.Read 15 Oct 2026 · plinklabs.org
Session control
Teachers sign in with their school Microsoft account, select a class, choose bundles and start or end a session from a browser dashboard.Read 15 Oct 2026 · plinklabs.org
Soft enforcement limitation
The maker explicitly says a motivated student can bypass enforcement, with tampering surfaced as an integrity signal rather than prevented.Read 15 Oct 2026 · plinklabs.org
Student experience
Off-list apps are set aside rather than closed, while off-list Edge pages show a friendly block page with a request-access option.Read 4 Oct 2026 · plinklabs.org
Support model
Support is handled publicly through GitHub issues rather than a private ticket queue or mailing list.Read 15 Oct 2026 · plinklabs.org
Supported student systems
Student enforcement supports Windows 10 version 1809 or later and Windows 11, with Microsoft Edge Chromium required.Read 15 Oct 2026 · plinklabs.org
Unsupported student systems
There is no student agent for macOS, ChromeOS, iPadOS or phones; the teacher dashboard runs in a modern browser.Read 15 Oct 2026 · plinklabs.org
Web enforcement
An Edge extension checks navigation against the session allowlist and displays a friendly block page with an access-request action.Read 15 Oct 2026 · plinklabs.org

Plans and prices

Anchor Free Free; no licence fee or per-seat charge Self-hosted backend · single school per deployment · Azure hosting costs may apply Read 4 Oct 2026 · plinklabs.org
Anchor software Free no licence fee or per-seat charge self-hosted · Windows/Edge student client · school supplies Azure backend Read 15 Oct 2026 · plinklabs.org
Azure hosting estimate €24 a month Azure list prices, Belgium Central, excluding VAT about 1,000 students · Basic B1 App Service · SQL Standard S0 · free-tier Static Web App Read 15 Oct 2026 · plinklabs.org
Azure hosting estimate with larger database €43 a month Azure list prices, Belgium Central, excluding VAT about 1,000 students · Basic B1 App Service · SQL Standard S1 · free-tier Static Web App Read 15 Oct 2026 · plinklabs.org

Every Anchor plan and price →

Strong points and limits

Strong points

  • Free plan with no licence or per-seat charge
  • Live dashboard shows student states and off-list events
  • Microsoft 365, Smartschool, and GeoGebra bundles
  • Self-hostable GPL-3.0 source code
  • Observes activity only during active sessions

Limits

  • No student agent for Mac, Chromebook, iPad, or phone
  • Other browsers are outside student-device scope
  • Determined students can bypass soft enforcement
  • No support ticket queue

Who it suits

Anchor suits schools and teachers running focus sessions on Windows 10 version 1809 or later and Windows 11 devices. It is intended for managed or bring-your-own-device Windows classrooms.

Verdict

Anchor specifies a focused Windows classroom workflow with live session controls, filtering, and clear privacy boundaries. Its device and browser coverage, soft enforcement, and self-managed hosting requirements matter before adoption.

Where Specifiction places it

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