---
title: "The Right Context, Not All of It"
subtitle: "A lesson in context engineering: what an agent needs before it starts, where each piece lives, and how it survives the move between sessions, harnesses, models and machines"
url: "https://talirezun.com/library/right-context-not-all-of-it"
markdown: "https://talirezun.com/library/right-context-not-all-of-it.md"
type: "Essay"
brand: "From Lab to Life"
published: "2026-09-30"
updated: "2026-10-21T14:48:25.322Z"
authors: ["Dr. Tali Režun"]
series: "The Curator"
topics: ["Agent Harness","Agent Memory","Chasing Jarvis","Context Engineering","Open Source","The Curator"]
---

# The Right Context, Not All of It

*A lesson in context engineering: what an agent needs before it starts, where each piece lives, and how it survives the move between sessions, harnesses, models and machines*

- URL: https://talirezun.com/library/right-context-not-all-of-it
- Type: Essay
- Brand: From Lab to Life
- Published: 2026-09-30
- Updated: 2026-10-21
- Author: Dr. Tali Režun
- Series: [The Curator](https://talirezun.com/library?series=the-curator)
- Topics: Agent Harness, Agent Memory, Chasing Jarvis, Context Engineering, Open Source, The Curator

## Summary

Written deliberately as a lesson rather than a product story, taught through The Curator v3.80.0.

## Overview

Written deliberately as a lesson rather than a product story, taught through The Curator v3.80.0. Uses the analogy of a brilliant contractor who forgets everything each evening and needs an onboarding pack. Five lessons:
1. **What context is.** Start a session near 10% of the window and hand off by about 80%; the session boundary, not window size, is the constraint.
2. **Why leave your harness at all.** Subscription economics and model specialisation (build in one tool, audit in another).
3. **Context dissected:** Documents (handbook), Brief (standing orders, with read-back, a conflict protocol and capability fallback), Handoff (shift note), Journal (logbook) and the Wiki (library). Rule: "Knowledge accumulates. State supersedes. A canonical document is replaced whole and read verbatim."
4. **Budgeting.** Read-first vs on-request vs not-at-start documents, the session-start meter, and reading-budget presets.
5. **Several harnesses and several computers.** Exactly three routes (Personal Sync, the project's git, set up once per computer), the Setup check, and the menu-bar widget.
Includes a ten-step setup guide, a classroom exercise, and an honest "what is not finished" list. Live handover tested between Claude Code, Antigravity and OpenCode; Codex and Cursor untested.

## Editions

Where to read the full work (the canonical edition first):

- [Medium](https://medium.com/@talirezun/the-right-context-not-all-of-it-0e7c0b21975f) (canonical)
- [Substack](https://talirezun.substack.com/p/the-right-context-not-all-of-it)

## Related

- [Every Product Needs a Home](https://talirezun.com/library/every-product-needs-a-home.md)
- [Context as Architecture: Full-Corpus Grounding, Orchestrated Agentic Development, and Compliance-by-Design in a Production AI Assistant Platform](https://talirezun.com/library/context-as-architecture.md)
- [Knowledge Accumulates, State Supersedes: Structuring and Carrying Context for Multi-Session, Multi-Harness AI Agent Work — A Design Study of The Curator, an Open-Source Context Engine](https://talirezun.com/library/knowledge-accumulates-state-supersedes.md)

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HTML page: https://talirezun.com/library/right-context-not-all-of-it · The whole Library: https://talirezun.com/library.md