---
name: build-migrate
description: Placeholder, not part of any flow yet. Will start an Introspection agent (Recipe) from an agent built on another harness, such as Vercel's eve, LangChain's Deep Agents, or Claude Code and Codex skills. Until it is built, start with build-brainstorm and use the old agent's behaviour as the owner's material.
metadata:
  min-cli-version: "0.73.0"
---

# Build: migrate (placeholder)

Not built yet, and no agent loads it. Until it is, an owner with an existing agent starts with build-brainstorm, "From scratch", and shares the old agent's instructions, tests and example runs as material.

## What it will do

Turn an agent that already works somewhere else into approved cases and a translation plan, so build-draft writes a Recipe that behaves the way the old agent's users rely on. It will be the third way to start a build, beside "From scratch" and "From a template".

- Migrate only when an existing implementation has behaviour that must survive. An agent that is already a Recipe is improve's; an outcome with nothing behind it is build-brainstorm's.
- Keep what the old agent does for people, not how it is built: no known bugs, dead abstractions or host-only steps carried over, and every intended difference agreed with the owner.
- Turn real runs of the old agent (its tests, evals, traces) into the cases, and, when a case's result differs, fix the translation at the first point the runs diverge.

[The translation table](references/translation.md) is the starting point for how each harness's pieces become a Recipe's.

## Playbooks to write

A harness agent already has a Recipe's shape: one loop with instructions, skills, tools, files and subagents, so most of it carries over piece by piece. Each harness needs its own playbook (where its instructions, tools, skills and evals live, how to read real runs of it, and what has no counterpart) before this skill is wired in:

- Vercel's eve
- LangChain's Deep Agents
- Claude Code and Codex skills

An agent built directly on an SDK (LangGraph, Mastra, the OpenAI Agents SDK, the Vercel AI SDK) is out of scope. It has no harness to map from: its behaviour lives in application code, so moving it means writing a new set of skills, with scripts that make the original tool calls. That's a rebuild with build-brainstorm, using the old agent's behaviour as material, not a migration.