What is contentful-migration AGENTS.md?

A guide for coding agents working in the Contentful migration repository. Contentful is a service for managing website content, and this guide explains where to find project information, how to build and test it, and which files have special rules.

Use it when modifying, testing, or reviewing the Contentful migration library, especially changes involving migration steps, TypeScript types, fixtures, builds, or dependencies.

It helps an agent understand the repository before changing code and avoid breaking generated files, test recordings, the public TypeScript API, or related dependency versions.

How contentful/contentful-migration configures Codex and OpenCode

Reuse

Borrowing it

Nothing to install: this file belongs to contentful/contentful-migration. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file

curl -O https://raw.githubusercontent.com/contentful/contentful-migration/main/AGENTS.md

Clone the repo

git clone --depth 1 https://github.com/contentful/contentful-migration

Made for: Codex, OpenCode.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

README.md

[![agentmods](https://agentmods.dev/badge/instructions/contentful/contentful-migration/agents-md/github.svg)](https://agentmods.dev/instructions/contentful/contentful-migration/agents-md)

Your own site

<a href="https://agentmods.dev/instructions/contentful/contentful-migration/agents-md"><img src="https://agentmods.dev/badge/instructions/contentful/contentful-migration/agents-md/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

Your own site · 80×15

<a href="https://agentmods.dev/instructions/contentful/contentful-migration/agents-md"><img src="https://agentmods.dev/badge/instructions/contentful/contentful-migration/agents-md.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 833 This file is loaded in full into every session.

When invoked 833 The same file — it is already loaded in full.

Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.

Origin original No closer match found in the catalogue.

Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

Model	Per session	Once invoked
Fable 5.1	$0.00833	$0.00833
Opus 5.5	$0.00333	$0.00333
Sonnet 5.5	$0.00167	$0.00167
Haiku 4.5	$0.00083	$0.00083

Measured 2mo ago against content hash e9166236bc3b, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

contentful-migration AGENTS.md scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2mo ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

AGENTS.md · 55 lines

How it starts

The opening of the file, as written. The whole thing — 55 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Agent Guide

Read this file first. It tells you where to find context in this repo.

Quick Reference

What you need	Where to look
How this repo is structured	ARCHITECTURE.md
How to build/test/run	CONTRIBUTING.md
Why decisions were made	docs/ADRs/
What this repo does	README.md
PR review rules	.bito/guidelines/
Active specs/work	docs/specs/

Sharp Edges & Invariants

Never edit built/ — this is generated output from npm run build. It is gitignored. Always modify source in src/.
Never hand-edit test/fixtures/ — these are Nock HTTP recordings. Re-record with NOCK_RECORD=1, not manual edits.
index.d.ts is manually maintained — it is the public TypeScript API surface. It must stay in sync with DSL capabilities in src/lib/migration-steps/. Changes here affect every TypeScript consumer.
CMA version alignment is critical — this library's contentful-management dependency must stay aligned with contentful-cli, contentful-import, contentful-export, and contentful-batch-libs. Do not bump it in isolation.
This is a library, not a CLI — the user-facing CLI lives in contentful-cli. This repo owns the migration DSL and execution engine. Do not add CLI UX features here; they belong in contentful-cli.
CommonJS output — tsconfig.json targets CommonJS modules. Do not switch to ESM without coordinating with all downstream consumers.
npm ci requires npx allow-scripts after — .npmrc has ignore-scripts=true for security. The prepare script will not run automatically; you must explicitly run npx allow-scripts for packages that need post-install scripts (like esbuild for vitest).
Integration/e2e tests need credentials — they hit real CMA. Never run them without proper CONTENTFUL_SPACE_ID, CONTENTFUL_INTEGRATION_TEST_CMA_TOKEN, and CONTENTFUL_ORGANIZATION_ID environment variables.
Conventional Commits required — semantic-release derives versions from commit messages. Incorrect commit types will produce wrong version bumps.

Read the full file on GitHub · 55 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

2mo ago First seen · 55 lines · 833 tokens per session scan A e9166236bc3b

Subscribe to this mod's changes

contentful-migration AGENTS.md is an instructions file published in the GitHub repository contentful/contentful-migration (345 stars, last pushed 4d ago), licensed MIT. It adds 833 tokens to every session, about $0.0033 per session on Opus 5.5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

contentful-migration AGENTS.md next to 6 instructions from other repositories
Mod	Type	Stars	Last push	Licence	Scan	Tokens	Works with
contentful-migration AGENTS.mdcontentful/contentful-migration	Instructions file	345	4d ago	MIT	A	833	Codex, OpenCode
vscode buildNext.instructions.mdmicrosoft/vscode	Instructions file	195k	yesterday	MIT	A	9,719	GitHub Copilot
next.js AGENTS.mdvercel/next.js	Instructions file	143k	yesterday	MIT	A	7,461	Codex, OpenCode
langchain AGENTS.mdlangchain-ai/langchain	Instructions file	149k	yesterday	MIT	A	4,680	Codex, OpenCode
vscode oss-third-party-notices.instructions.mdmicrosoft/vscode	Instructions file	195k	yesterday	MIT	A	5,516	GitHub Copilot
vscode copilot-instructions.mdmicrosoft/vscode	Instructions file	195k	yesterday	MIT	A	3,093	GitHub Copilot
deepseek-harness AGENTS.mddeepseek-ai/deepseek-harness	Instructions file	274k	2d ago	MIT	A	4,313	Codex, OpenCode

contentful-migration: Instructions file for Codex