An AI assistant that nags you on purpose

What it does

Vellum Assistant is a cross-platform personal AI that runs persistently and talks to you through macOS, iOS, web, Slack, Telegram, or Twilio. It stores structured memory—identity, preferences, projects, events—with local embeddings by default, then uses that memory to initiate conversations without being prompted. A trust engine resolves every actor as guardian, trusted, or unknown, and defaults to no access.

The interesting bit

The personality layer is genuinely odd: the assistant observes how you write during onboarding and generates its own SOUL.md and reflection journal. An hourly self-check loop lets it re-read notes, spot deadlines, and message you—unless you’re already mid-conversation. It’s the rare open-source project that treats proactivity as a feature, not a bug.

Key highlights

• Eight memory types with per-type staleness windows, source attribution, and deduplication; hybrid dense + sparse retrieval
• Model-agnostic: Claude, OpenAI, Gemini, or Ollama; embeddings default to local ONNX with cloud fallback
• Sandboxed skills via manifest-driven plugins (SKILL.md + TOOLS.json) that inject tools at runtime
• Fail-closed security: credentials isolated in a separate process, never exposed to the model; every tool sandboxed
• Self-hostable local mode or managed cloud sign-in; the company behind it sells a separate commercial platform

Caveats

• The CLI exists but the README calls it secondary: “the desktop app is our primary focus”
• 638 stars suggests early traction; some ambitious features (proactive reasoning, self-authored personality) are hard to verify without extended use
• iOS and web clients are mentioned in the description but the README emphasizes macOS; exact platform parity is unclear

Verdict

Worth a look if you want an assistant that actually owns its own state rather than waiting for prompts. Skip it if you need a mature, battle-tested automation layer—this is experimental infrastructure with strong opinions about identity and memory.