Rosa Del Mar

Daily Brief

Issue 57 2026-02-26

Capability As Feasibility Knowledge Plus Executable Proof

Issue 57 Edition 2026-02-26 6 min read
General
Sources: 1 • Confidence: High • Updated: 2026-04-13 03:58

Key takeaways

  • The document asserts that building software skill depends heavily on knowing what is possible and having a rough idea of how to accomplish it.
  • The document asserts that collected working examples can be used as inputs for coding agents by prompting the agent to build new things by combining two or more existing examples.
  • Willison publishes notes via blog/TIL posts and maintains over a thousand GitHub repositories, many of them small proof-of-concepts.
  • The document asserts that coding agents make the hoarding approach more powerful by fetching and reusing source code from the internet and local codebases as context for new tasks.
  • tools.simonwillison.net is described as Willison’s largest collection of LLM-assisted single-file HTML tools with embedded JavaScript and CSS that solve specific problems.

Sections

Capability As Feasibility Knowledge Plus Executable Proof

  • The document asserts that building software skill depends heavily on knowing what is possible and having a rough idea of how to accomplish it.
  • The document asserts that documenting a useful trick once with a working code example allows agents to consult it and solve similarly shaped projects in the future without re-deriving the technique.
  • The document asserts that knowing something is theoretically possible is not equivalent to having personally seen it working as running code, and that the latter is preferable.
  • The document asserts that accumulating answers to obscure or broad feasibility questions increases the likelihood of spotting problem-solving opportunities others miss.

Agentic Recombination As A Development Pattern (Examples To Integrated Tools)

  • The document asserts that collected working examples can be used as inputs for coding agents by prompting the agent to build new things by combining two or more existing examples.
  • Willison built a browser-based OCR tool by combining prior snippets using PDF.js to render PDF pages as images and Tesseract.js (WebAssembly) to extract text from those images in JavaScript.
  • A single prompt that included two example codebases produced a working proof-of-concept HTML page that converted dropped PDFs into per-page JPEGs and ran OCR, displaying results beneath each image.
  • The document asserts that iterating a few times with a model can quickly turn an LLM-generated proof-of-concept into a useful tool with lasting personal value.

Knowledge Hoard As Reusable Capital (Repos, Tils, Single-File Tools, Agent Research Outputs)

  • Willison publishes notes via blog/TIL posts and maintains over a thousand GitHub repositories, many of them small proof-of-concepts.
  • tools.simonwillison.net is described as Willison’s largest collection of LLM-assisted single-file HTML tools with embedded JavaScript and CSS that solve specific problems.
  • The simonw/research repository is described as containing larger agent-driven examples where a coding agent researched a problem and returned working code plus a written report.

Operational Bottlenecks In Agent Toolchains (Retrieval Fidelity And Context Packaging)

  • The document asserts that coding agents make the hoarding approach more powerful by fetching and reusing source code from the internet and local codebases as context for new tasks.
  • Willison often instructs agents to clone his public repositories to /tmp and mine them for examples to apply to new projects.
  • When using Claude Code, specifying curl can be necessary because the default WebFetch tool summarizes pages instead of returning raw HTML.

Unknowns

  • How often does the recombination prompting pattern produce correct, maintainable integrations across different problem types beyond the OCR example?
  • What is the measured time/effort saved (or additional time incurred) by maintaining the hoard of repositories, notes, and single-file tools?
  • What are the failure modes when agents fetch and reuse external or local code, including incorrect dependency assumptions, licensing constraints, or security risks?
  • What retrieval and context-delivery practices are sufficient to ensure fidelity (raw source, correct versions, complete dependencies) when using agent toolchains?
  • What organizational process best supports sharing, searching, and maintaining a growing library of executable examples across a team rather than an individual?

Investor overlay

Read-throughs

  • Rising demand for developer tooling that packages runnable examples into agent-ready context, treating proof-of-concepts as reusable capital.
  • Increased value of code retrieval and context-delivery infrastructure that provides raw, version-correct source and dependencies for agent workflows.
  • Growth opportunity for lightweight, single-file, self-contained tools that solve narrow tasks and can be rapidly recombined into integrated utilities by agents.

What would confirm

  • More documented workflows and tools focused on fetching raw source, pinning versions, and bundling complete context for coding agents.
  • Teams adopting shared libraries of executable examples and small repos as standard practice, with search and reuse as a core workflow.
  • Repeated examples of agent prompts successfully recombining multiple known-good snippets into working prototypes with fewer iterations.

What would kill

  • Evidence that recombination prompting often yields brittle or unmaintainable integrations outside narrow demos, requiring heavy manual rework.
  • Persistent retrieval fidelity issues such as incomplete code, wrong versions, missing dependencies that prevent agents from producing runnable outputs reliably.
  • Material risks from reused code such as licensing conflicts or security issues that discourage organizations from agent-driven code reuse practices.

Sources

  1. 2026-02-26 simonwillison.net