---
kind: "stage-reading-key"
stage: "C4"
title: "Model: the field"
purpose: "Examine the model against the field account when supplied."
status: "finished"
closed_legs: 1
publication: "c070d990be88"
status_note: "This describes source publication c070d990be88, not live state."
authority: "This is a reading key. The linked contract and card hold the rules."
---

# C4: Model: the field

Examine the model against the field account when supplied.

This is a reading key. The linked contract and card hold the rules.

## 1. Reading order

1. [Contract](../reading/contract.md), [method](../reading/method.md), [standing instructions](../reading/standing.md).
2. Your recorded platform: [Claude](../reading/platform-claude.md) or [Codex](../reading/platform-codex.md).
3. [Full C4 card](../reading/stage-C4.md), then the run's head, diary and handler deliveries as that card prescribes.

## 2. Inputs and permitted reading

Use the full card's startup packet and reading boundaries. Do not use files from later stages merely because this repository contains them. Historical interviews use the files in their selected bundle.

## 3. Outputs, quoted from the card

- `field-C4.md`
- tentative entries in `model/elements.jsonl` or `model/arrows.jsonl`, each with `"origin": "from-field"`, `"status": "tentative"`, `field_support` and a `model/history.jsonl` line
- wherever this stage changes something, `model-C4.md`, `structure-C4.md` and `concept-C4.md`, each a whole file superseding the stage C3 file (or the stage C2 file where C3 wrote none), and `manifest-C4.txt`, one line per file of `manifest-C3.txt` saying whether it has a stage C4 successor, which stage C5 reads first
- `notes-C4.md`.

## 4. Legs

| Leg | Role | Repeats | Interview point |
|---|---|---|---|
| `C4a` | the field | no | end |

## 5. Checks and handback

The stage card governs its checks. The [handler](../reading/handler.md) and [leg controller](../reading/legs.md) govern opening, close, pause and recovery. Do not infer permission to start from this page. Keep notes and the head current; the conversation and filesystem must match at any resumable close.

## 6. Published record

Status: **finished**, 1 recorded closed legs. This describes source publication `c070d990be88`, not live state.

## 7. Historical instructions and settings

Source status clarified on 29 October 2026: the Field agent was still working when it supplied C4. This checkpoint contains its interim reading and comments, not a comparison against its completed model. That fuller comparison remains pending.

[Historical context and evidence](../guides/history.md).


[Checkpoint interviews](../interviews.html?stage=C4) · [Source hashes](../sources/manifest.json)