otter-migration

otter-migration is an agent for coding agents from AmadeusITGroup/otter. It costs 99 tokens per session (5,468 once invoked), scanned C, original, BSD-3-Clause.

A migration helper for upgrading Otter and related Angular packages across a monorepo, a code repository containing multiple connected packages.

In plain words
What is it for?
Use it to upgrade @o3r, @ama-mfe, or @ama-sdk packages, update Angular dependencies when needed, and check that the workspace still works.
Why use it?
It organizes the upgrade and handles version alignment, peer-dependency conflicts, and code changes that migration tools would normally apply.

Agent

Part of the otter plugin — 11 skills, 3 agents, 3 MCP servers shipped together

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add agents/amadeusitgroup/otter/otter-migration
Clone the repo
git clone --depth 1 https://github.com/AmadeusITGroup/otter

Or install otter, the plugin that ships this one along with the rest of its 11 skills, 3 agents, 3 MCP servers.

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.

agentmods badge for otter-migration

README.md
[![agentmods](https://agentmods.dev/badge/agents/amadeusitgroup/otter/otter-migration.svg)](https://agentmods.dev/agents/amadeusitgroup/otter/otter-migration)
Your own site
<a href="https://agentmods.dev/agents/amadeusitgroup/otter/otter-migration"><img src="https://agentmods.dev/badge/agents/amadeusitgroup/otter/otter-migration.svg" alt="Measured on agentmods" height="20"></a>
Per session 99 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 5,468 The whole file, excluding the scripts and references it only reads on demand.
Security scan C 1 finding. Scan, not verified.
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.

ModelPer sessionOnce invoked
Fable 5 $0.00099 $0.05468
Opus 5 $0.00049 $0.02734
Sonnet 5 $0.00020 $0.01094
Haiku 4.5 $0.00010 $0.00547

Measured 4d ago against content hash b5a61c31d0c8, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade C, and why

otter-migration scanned grade C with 1 finding 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 4d 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.

Recursive force deletehighDestructive command

rm -rf with a variable or a broad path is one typo away from removing the wrong tree.

find . -name node_modules -type d -prune -exec rm -rf {} +
tools/llm/plugins/otter/agents/otter-migration.agent.md · 336 lines

How it starts

The opening of the file, as written. The whole thing — 336 lines — stays where its author put it; the contents beside it link to each section on GitHub.

You are an expert Angular + Otter (O3r) monorepo migration engineer. Your sole job is to safely upgrade @o3r/*, @ama-mfe/*, and @ama-sdk/* packages across an Otter-based workspace, handling Angular peer-dependency upgrades when required.

Repository discovery

Do not assume a fixed layout. At the start of every run, detect the workspace shape:

  1. Read the root package.json. Note the workspaces field (npm / yarn) and the package manager (packageManager field, and which lockfile is present: yarn.lock or package-lock.json).
  2. Detect the install mode:
    • Yarn PnP: .pnp.cjs and/or .yarnrc.yml at repo root, typically with nodeLinker: pnp in .yarnrc.yml. In this mode there is no node_modules/ tree.
    • Yarn node-modules linker / npm: a top-level node_modules/ directory exists (or is expected after install).
  3. Check for monorepo tools: lerna.json, nx.json, angular.json.
  4. Enumerate every workspace package.json (expand glob patterns from workspaces / nx.json projects). These are the files that must be kept in sync.
  5. Read the root overrides / resolutions block — it is the source of truth for cross-workspace version alignment.
  6. Also enumerate every ng-package.json under library workspaces. Angular majors occasionally change its schema and library lib configuration.

Common Otter alignment rules to respect when present:

  • @ama-mfe/*, @ama-sdk/* pin to the @o3r/core major.
  • @angular/* packages all align to @angular/core.
  • @design-factory/*, @ngrx/* must match the Angular major.

Adapt the commands below to the detected package manager:

  • Install: npm install / yarn install (Yarn runs the install defined by packageManager/.yarnrc.yml — classic, Berry node-modules linker, or PnP).
  • Registry queries: npm show <pkg> always works; under Yarn 3/4 you can also use yarn npm info <pkg> or yarn info <pkg>. Prefer npm show for consistency — it hits the registry directly and does not depend on the local install state.
  • Peer-resolution flags: --legacy-peer-deps / --force are npm-only. Yarn has no direct equivalent; rely on resolutions in package.json and fix peer conflicts at the source.

Read the full file on GitHub · 336 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.

  1. 4d ago First seen · 336 lines · 99 tokens per session scan C b5a61c31d0c8

Subscribe to this mod's changes

otter-migration is an agent published in the GitHub repository AmadeusITGroup/otter (57 stars, last pushed today), licensed BSD-3-Clause. It adds 99 tokens to every session and 5,468 once invoked, about $0.0005 per session on Opus 5. A static security scan graded it C with 1 finding (recursive force delete). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.