Magnitude
Open-source browser-agent framework focused on AI-driven end-to-end testing — natural-language test cases that translate to Playwright actions. Y Combinator 2025; positions itself as 'Playwright + Claude for QA' rather than general autonomy.
At a glance
- Type
- OSS browser-agent framework for web tests (YC)
- Tier
- T3
- Section
- Computer-use & desktop agents
- Created
- 2025 (GitHub first commit)
- Latest release
- v0.x ongoing on GitHub
- License
- Apache 2.0
- Pricing
- OSS free; cloud / enterprise on roadmap
- Funding
- YC 2025 batch (~$500k standard YC)
Taxonomy
- storage
- file
- retrieval
- injection
- persistence
- session
- update
- agent-controlled
- unit
- document
- governance
- inspectable
- conflict
- human-arbitrate
When to use
Optimised for: Natural-language E2E tests as the unit of work
Anti-fit: Test-automation focus — not for autonomous operator-style tasks
Pros & cons
Pros
YC-backed; clean test-first framing; Apache 2.0 license.
Cons
Narrow scope (QA); small team; no funding disclosure beyond YC.
Claims & capabilities
YC-backed; OSS; visual-first agent loop (screenshots not just DOM)
Technical surface
- API surface
- CLI + Playwright-style API
- Backend storage
- Local Playwright state
- Deployment
- Library / CLI; runs locally
- Embedding model
- not applicable — not a memory product
- Multi-tenancy
- Single-tenant (local CLI)
- MCP
- searched not found
- A2A
- searched not found
- OpenTelemetry
- searched not found
Similar systems
Other computer-use & desktop agents in the catalog, ranked by inbound references.
- UI-TARS T2
ByteDance Seed's open-source GUI-agent foundation model — released Jan 2025; trained end-to-end on screenshot → action pairs. Comes with UI-TARS-Desktop (Electron app) that runs the model against the user's screen. SOTA on OSWorld at release; weights on HuggingFace.
- Browser Use T1
Python library that turns any LLM into a browser agent — extracts DOM into a structured representation the LLM can act on (rather than pure screenshot). Browser Use Inc. raised $17M seed Q1 2025 (Felicis); cloud product at cloud.browser-use.com. Project is one of the most-starred browser-agent OSS repos (~60k stars).
- Bytebot T3
Open-source desktop-agent runtime that runs an LLM-controlled Linux desktop inside Docker — uses xdotool / X11 capture for control. Pitched as the 'self-hosted Operator' alternative; agent sees a real desktop screen, not just a browser.
- Claude for Chrome T1
Anthropic's Chrome extension that lets Claude act inside the user's existing browser (rather than a sandboxed one). Research preview launched August 2025 — limited to Claude Max tier. Distinct from Anthropic Computer Use (which is the API substrate); this is the consumer surface that uses it inside Chrome.
- Highlight AI T2
Always-on desktop AI assistant that watches the user's screen (across all apps) and answers questions / takes actions based on what's currently visible. Mac + Windows. Founded by Mac Bishop (ex-Mixpanel); raised $13M Series A from Aspect / Lightspeed (Oct 2024). Distinguishes itself from Rewind by being action-oriented (not just recall).
- Hyperbrowser T2
Cloud-hosted headless browser API tuned for AI agents — captcha solving, stealth mode, session recordings. Y Combinator S24; pitched as a faster / cheaper Browserbase alternative. Used as substrate by agents that need browser execution but don't want to run their own Chromium fleet.
Related systems
References (2)
- Anthropic Claude (foundation models) depends on at runtime — adjacent-infrastructure cell: Playwright; Anthropic / OpenAI APIs
- OpenAI GPT family (GPT-5 / GPT-4o / o3 / o4) depends on at runtime — adjacent-infrastructure cell: Playwright; Anthropic / OpenAI APIs