PKM Wiki

Source - YB 2026 - Revisiting the Memex

2 min read

Citation

YB, "Revisiting the Memex: A soul, heartbeat, and cron jobs," Engineering Agency (Substack), February 20, 2026. URL: https://engineeringagency.substack.com/p/revisiting-the-memex

Overview

Reframes Vannevar Bush's 1945 Memex vision for the AI era. Bush imagined a mechanized private file and library — essentially an archival device. YB argues the contemporary memex has become a collaborative partner: not a storage system we consult, but an agentic system we work with. The mechanization is trivial (markdown files + scheduled processes); what makes it work is accumulated personal context.

Main Thesis

The memex has evolved from passive repository to active partner. Bush's original vision of "a mechanized private file and library" treated the device as a recall system. The contemporary memex is a consultant — one that reads from a vault and proposes actions, drafts, and answers. The hardware is commodity (text files, cron jobs, markdown); the differentiator is the compounded personal context that lets the agent perform well.

Architecture Elements Described

  • agent-rules.md — governing instructions (the agentic constitution)
  • Subroutines — specific workflows with defined jobs (e.g., "tend the vault")
  • PR documentation — Knowledge Work PRs-style audit trail of changes
  • Heartbeat / cron jobs — scheduled processes that trigger subroutines

Key Concepts

  • The soul of the agent. Personal context embedded in vault notes is what differentiates one user's agent from another's. Commoditized tooling + personalized context = differentiated output.
  • Agentic memex. The Bush archive becomes an active partner when paired with an LLM that reads it. This is a substantive reframe, not a cosmetic relabel.
  • Simple substrate, rich context. The implementation is small (plain text, cron, markdown). The value comes from what is written, not from the tooling around it.

Practical Recommendations

  • Build agents around existing knowledge systems (Obsidian vaults)
  • Use voice interfaces for rapid agent prototyping and context capture
  • Document agent rules before execution (alignment before action)
  • Implement feedback loops with AI for iterative refinement
  • Create audit trails through PR-style documentation

Why This Matters for PKM

  • Updates the canonical history. The History of Note-Taking article's Memex section should be read alongside this piece as a contemporary reinterpretation.
  • Ties together the YB corpus. The agentic constitution, subroutines, Knowledge Work PRs, and context-compounding all fit under the "agentic memex" umbrella.
  • Reframes the vault. A vault written for the agentic memex is different in emphasis from one written purely for human reading — more explicit context, more structured orientation, more documentation of reasoning.

Concepts Introduced or Amplified

  • Agentic memex — the contemporary, agent-partnered version of Bush's memex
  • Soul of the agent — personal context as differentiator
  • Simple substrate, rich context — architectural principle