Glasp
Browser highlighting, notes, and shared knowledge discovery
Glasp's solo core is compact: build a private web highlighting workspace that imports user-supplied URLs or files, extracts metadata, supports notes, and searches the local corpus. A competent builder can reach a useful personal version in one sitting, while the paid product mainly wins on data, import reliability.
Build verification: not recorded. How we judge buildability
What you give up
- team libraries and institutional access
- licensed scholarly metadata
- publisher-specific import reliability
- citation graph scale
Why people still pay
Glasp: Researchers pay for correct metadata, resilient importers, citation coverage, and workflows that survive publisher and browser changes.
Your build guide
The stack, security requirements, and agent rules for a focused replacement.
Before you start
- A supported Node release, a writable local data directory and a separate backup location. Bind to localhost; remote use requires authentication and HTTPS first.
- Implementation components: Node.js, TypeScript and Express with server-rendered HTML and small browser modules. SQLite through better-sqlite3 with migrations, prepared statements and a single background worker.
- Scope boundary: team libraries and institutional access; licensed scholarly metadata
Use these project rules and optional skill references alongside the prompt. Review each skill before adding it to your agent; the AGENTS.md export includes the same guidance.
Optional external skill: web-design-guidelines — Review web interfaces for accessibility, keyboard focus, forms, navigation and interaction quality. Review its instructions and compatibility before use; it does not grant deployment, data-access or publication permission.
Optional external skill: sharp-edges — Review security-sensitive APIs and configuration for dangerous defaults and easy-to-misuse interfaces. Review its instructions and compatibility before use; it does not grant deployment, data-access or publication permission.
Project rule — data model: permitted page captures, text anchors, highlight ranges, notes, tags and source revisions
Project rule — preserve this invariant: A highlight anchor records enough context to detect source changes; imports do not bypass paywalls or private access restrictions.
Project rule — acceptance evidence: Reopen a page whose text changed and mark an unmatched highlight rather than attaching it to the wrong sentence; exported notes retain citations.
Implementation plan
Phase 1
Scope and fixtures. Implement this bounded workflow: Capture selected passages with a small browser extension, store the source URL and matching text context and review them in a private library. Export highlights as Markdown with source links and optional user-supplied transcripts. Record prerequisites, select representative user-owned fixtures and document the unsupported features: team libraries and institutional access; licensed scholarly metadata
Phase 2
Durable model. Model permitted page captures, text anchors, highlight ranges, notes, tags and source revisions Add migrations or a versioned document format, explicit validation, stable IDs and a visible import-error report. Preserve this rule: A highlight anchor records enough context to detect source changes; imports do not bypass paywalls or private access restrictions.
Phase 3
Complete the first useful path. Implement the workflow's input, review and output interface, with clear controls and explicit empty/error states. Use short SQLite transactions and persist job state before starting work. Give retries stable operation IDs; report incomplete or unknown results instead of silently repeating them.
Phase 4
Permissions and integration failure. Reject unexpected origins and unbounded request bodies even on localhost. Keep credentials outside the database export and redact sensitive text from logs. Request integration credentials and permissions only for the enabled feature; show a disconnected state instead of mock results.
Phase 5
Portable handoff. Use a consistent SQLite backup and an attachment manifest. Export portable JSON/CSV, then restore to a new directory without overwriting the original data. Include setup, operating limits, fixture walkthrough and shutdown/restart instructions in the README.
Phase 6
Acceptance scenarios. Reopen a page whose text changed and mark an unmatched highlight rather than attaching it to the wrong sentence; exported notes retain citations. Repeat the workflow after restart and with a denied permission or unavailable dependency; show recoverable failure rather than a success placeholder.
WORKING SLICE Capture selected passages with a small browser extension, store the source URL and matching text context and review them in a private library. Export highlights as Markdown with source links and optional user-supplied transcripts. Build this scoped Glasp-inspired workflow with a documented data model and visible failure states. Architecture - Node.js, TypeScript and Express with server-rendered HTML and small browser modules. - SQLite through better-sqlite3 with migrations, prepared statements and a single background worker. Prerequisites and limits A supported Node release, a writable local data directory and a separate backup location. Bind to localhost; remote use requires authentication and HTTPS first. Outside this release: team libraries and institutional access; licensed scholarly metadata Data model and correctness permitted page captures, text anchors, highlight ranges, notes, tags and source revisions Invariant: A highlight anchor records enough context to detect source changes; imports do not bypass paywalls or private access restrictions. Use short SQLite transactions and persist job state before starting work. Give retries stable operation IDs; report incomplete or unknown results instead of silently repeating them. Security and privacy Reject unexpected origins and unbounded request bodies even on localhost. Keep credentials outside the database export and redact sensitive text from logs. Recovery and export Use a consistent SQLite backup and an attachment manifest. Export portable JSON/CSV, then restore to a new directory without overwriting the original data. Implementation order 1. Phase 1 — Scope and fixtures. Implement this bounded workflow: Capture selected passages with a small browser extension, store the source URL and matching text context and review them in a private library. Export highlights as Markdown with source links and optional user-supplied transcripts. Record prerequisites, select representative user-owned fixtures and document the unsupported features: team libraries and institutional access; licensed scholarly metadata 2. Phase 2 — Durable model. Model permitted page captures, text anchors, highlight ranges, notes, tags and source revisions Add migrations or a versioned document format, explicit validation, stable IDs and a visible import-error report. Preserve this rule: A highlight anchor records enough context to detect source changes; imports do not bypass paywalls or private access restrictions. 3. Phase 3 — Complete the first useful path. Implement the workflow's input, review and output interface, with clear controls and explicit empty/error states. Use short SQLite transactions and persist job state before starting work. Give retries stable operation IDs; report incomplete or unknown results instead of silently repeating them. 4. Phase 4 — Permissions and integration failure. Reject unexpected origins and unbounded request bodies even on localhost. Keep credentials outside the database export and redact sensitive text from logs. Request integration credentials and permissions only for the enabled feature; show a disconnected state instead of mock results. 5. Phase 5 — Portable handoff. Use a consistent SQLite backup and an attachment manifest. Export portable JSON/CSV, then restore to a new directory without overwriting the original data. Include setup, operating limits, fixture walkthrough and shutdown/restart instructions in the README. 6. Phase 6 — Acceptance scenarios. Reopen a page whose text changed and mark an unmatched highlight rather than attaching it to the wrong sentence; exported notes retain citations. Repeat the workflow after restart and with a denied permission or unavailable dependency; show recoverable failure rather than a success placeholder. Acceptance Reopen a page whose text changed and mark an unmatched highlight rather than attaching it to the wrong sentence; exported notes retain citations. Use real source data or clearly labeled fixtures. Explain unsupported input and provider failures; do not fabricate analytics, delivery receipts, accuracy claims or security guarantees. Optional agent guidance Optional external skill: [web-design-guidelines](https://github.com/vercel-labs/agent-skills/blob/main/skills/web-design-guidelines/SKILL.md) — Review web interfaces for accessibility, keyboard focus, forms, navigation and interaction quality. Review its instructions and compatibility before use; it does not grant deployment, data-access or publication permission. Optional external skill: [sharp-edges](https://github.com/trailofbits/skills/blob/main/plugins/sharp-edges/skills/sharp-edges/SKILL.md) — Review security-sensitive APIs and configuration for dangerous defaults and easy-to-misuse interfaces. Review its instructions and compatibility before use; it does not grant deployment, data-access or publication permission. Project rule — data model: permitted page captures, text anchors, highlight ranges, notes, tags and source revisions Project rule — preserve this invariant: A highlight anchor records enough context to detect source changes; imports do not bypass paywalls or private access restrictions. Project rule — acceptance evidence: Reopen a page whose text changed and mark an unmatched highlight rather than attaching it to the wrong sentence; exported notes retain citations.
$ open in your agent (prompt prefilled, you press enter), copy the prompt or copy or download AGENTS.md
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Glasp pricing
| plan | monthly | annual (per mo) | what you get |
|---|---|---|---|
| free | $0/user | $0/user | Unlimited public highlights; 3 basic YouTube summaries/day; 1 tracked channel with 3 videos; 30 PDFs; 20 PDF chats/month; 20 AI-chat credits/month; 30 audio minutes/month. |
| pro | $15/user | $12.50/user | 1,000 advanced YouTube summaries/month; 5 tracked channels with 30 videos/channel; 100 PDFs; 500 PDF chats/month; 500 AI-chat credits/month; 300 audio minutes/month.Annual total is $150. The $15 month-to-month rate is derived exactly from the live page's crossed-out $180 regular annual total. |
| unlimited | $36/user | $30/user | 5,000 advanced YouTube summaries/30 days; 25 channels with 500 videos/channel; unlimited PDFs; 5,000 PDF chats/month; 2,000 AI-chat credits/month; 1,500 audio minutes/month.Annual total is $360. The $36 month-to-month rate is derived exactly from the live page's crossed-out $432 regular annual total. |
free tierunlimited public highlights; 3 basic YouTube summaries/day; 1 tracked channel/3 videos; 30 PDFs; 20 PDF chats/month; 20 AI credits/month; 30 audio minutes/month
billingmonthly + annual; annual Pro is $150 and Unlimited is $360
hidden coststaxes may be added; paid purchases are generally non-refundable; private/advanced AI usage is metered by separate monthly caps
pricing sources checked 2026-08-13 · pricing source ↗
Questions about Glasp
Can you build your own Glasp with AI?
The verdict is yes for the scoped workflow. Glasp's solo core is compact: build a private web highlighting workspace that imports user-supplied URLs or files, extracts metadata, supports notes, and searches the local corpus. A competent builder can reach a useful personal version in one sitting, while the paid product mainly wins on data, import reliability.
What does the Glasp build prompt cover?
The prompt starts with this scope: Capture selected passages with a small browser extension, store the source URL and matching text context and review them in a private library. Export highlights as Markdown with source links and optional user-supplied transcripts. Full-product capabilities excluded from the comparison include: team libraries and institutional access; licensed scholarly metadata; publisher-specific import reliability. Follow the implementation plan and its prerequisites before expanding the build.
How do I use the prompt, AGENTS.md and agent skills?
Start with the Glasp prerequisites and stack, then copy the prompt into your coding agent. Save the project rules as AGENTS.md in the project root. Linked skills are optional packages or source instructions for specific tasks; review their current contents and install only those matching the chosen stack. A skill does not supply API credentials or verify the finished app.
How long will this Glasp project take?
The catalogue estimate is one sitting for the limited scope. Setup, integration approvals, debugging, deployment and ongoing maintenance can add time. This is an estimate, not a delivery guarantee.
What would I give up by replacing Glasp?
team libraries and institutional access; licensed scholarly metadata; publisher-specific import reliability; citation graph scale. Glasp: Researchers pay for correct metadata, resilient importers, citation coverage, and workflows that survive publisher and browser changes.
What can I use instead of building Glasp?
Hypothesis: Highlights and margin notes on the live web; discovery is somebody else's problem. Check each option's license, hosting needs and feature limits.