---
title: "Hoard and Recombine"
description: "Collecting verified working code snippets and proof-of-concept tools to supply as concrete reference material for coding agents."
section: "concepts"
type: "concept"
created: "2026-08-22"
updated: "2026-08-30"
confidence: "high"
tags: ["technique", "agents", "knowledge-management", "workflow"]
canonical: "https://pyweb.dev/wiki/hoard-and-recombine"
---
# Hoard and Recombine

A high-leverage prompting and knowledge-management pattern: hoard working code solutions, TILs, and minimal prototypes, then prompt coding agents to synthesize new systems by combining those existing examples.


```text
save(concept) -> /concepts/<slug>.md + raw provenance
recombine(task) -> grep hoard by task keywords -> link relevant pages
```

## The Mechanism
1. **Hoard running proofs:** Knowing something is theoretically possible is weak; possessing a tested snippet (in a repo, TIL, or tool catalog) provides ground truth.
2. **Recombine via prompts:** Feed two or more working snippets into an agent (e.g. PDF.js canvas renderer + Tesseract.js WebAssembly worker) and prompt the agent to combine them into a single coherent interface or tool.
3. **Reference codebases in `/tmp`:** Direct agents to clone reference repositories into `/tmp` to inspect architecture, schemas, and API conventions without polluting the active repository commit tree.

## Why it Works
Agents excel at bridging disparate known patterns. Providing working reference code eliminates hallucinated APIs, establishes clear types and constraints, and produces working artifacts with minimal back-and-forth steering.

## Failure Modes

| Symptom | Root cause | Fix |
|---|---|---|
| Hoard becomes a junk drawer | Saving without curation criteria | Only save what you know how to reuse; prune what you have not touched in months |
| Recombination never happens | Artifacts saved in inaccessible formats | Save as structured, greppable markdown with provenance |
| Duplicate knowledge drifts | Same insight saved in multiple forms | One canonical page per concept; link variants to it |

## Rule of Thumb

A hoard earns its keep at recombination time: if the last three tasks
pulled nothing from it, the hoard is a liability, not an asset.

## Related
- [simon willison](/wiki/simon-willison)
- [agentic engineering patterns](/wiki/agentic-engineering-patterns)
- [build from scratch pedagogy](/wiki/build-from-scratch-pedagogy)
- [context engineering](/wiki/context-engineering)
- [tracer bullets](/wiki/tracer-bullets)

---

## Agent Navigation

cluster: person (170 pages) | betweenness: 114.3

### References (outbound)
- [Simon Willison](https://pyweb.dev/wiki/simon-willison.md)
- [Agentic Engineering Patterns](https://pyweb.dev/wiki/agentic-engineering-patterns.md)
- [Build-From-Scratch Pedagogy](https://pyweb.dev/wiki/build-from-scratch-pedagogy.md)
- [Context Engineering](https://pyweb.dev/wiki/context-engineering.md)
- [Tracer Bullets](https://pyweb.dev/wiki/tracer-bullets.md)

### Referenced by (inbound)
- [Agentic Engineering Patterns](https://pyweb.dev/wiki/agentic-engineering-patterns.md)

### Evidence (verified primary sources)
- [simon-willison-hoard-things-you-know-how-to-do-2026](https://pyweb.dev/wiki/raw/articles/simon-willison-hoard-things-you-know-how-to-do-2026.md) | origin: https://simonwillison.net/guides/agentic-engineering-patterns/hoard-things-you-know-how-to-do/ | ingested: 2026-08-22 | sha256: 485b18d29f13fc6296b3c6463ebbdf3cac03163f67aa1dad4efd85857d80c8bd
- [simon-willison-adding-a-new-content-type-2026](https://pyweb.dev/wiki/raw/articles/simon-willison-adding-a-new-content-type-2026.md) | origin: https://simonwillison.net/guides/agentic-engineering-patterns/adding-a-new-content-type/ | ingested: 2026-08-22 | sha256: 24736c484a2733f2aa23749c04e4917023445be7e4ec424144b3d03eed8973ef

### Machine endpoints
- Knowledge graph: https://pyweb.dev/api/graph.json
- Graph analysis: https://pyweb.dev/api/graph-analysis.json
- Context index: https://pyweb.dev/llms.txt