anth-migration-deep-dive

name	anth-migration-deep-dive
description	Migrate to Claude API from OpenAI, Gemini, or other LLM providers. Use when switching from GPT-4 to Claude, migrating from Text Completions, or building a multi-provider abstraction layer. Trigger with phrases like "migrate to claude", "openai to anthropic", "switch from gpt to claude", "multi-provider llm".
allowed-tools	Read, Write, Edit, Bash(npm:*), Grep
version	1.0.0
license	MIT
author	Jeremy Longshore <[e-mail]>
tags	["saas","ai","anthropic"]
compatible-with	claude-code

Anthropic Migration Deep Dive

Overview

Migration strategies for switching to Claude from OpenAI, Google, or other LLM providers, including API mapping, prompt translation, and multi-provider abstraction.

OpenAI to Anthropic API Mapping

OpenAI	Anthropic	Notes
openai.ChatCompletion.create()	anthropic.messages.create()	Different response shape
model: "gpt-4"	model: "claude-sonnet-4-20250514"	Different model IDs
messages: [{role, content}]	messages: [{role, content}]	Same format
functions / tools	tools	Similar but different schema key names
function_call	tool_choice	Different naming
response.choices[0].message.content	response.content[0].text	Different access path
stream: true → yields chunks	stream: true → SSE events	Different event format
System message in messages[]	system parameter (separate)	Claude separates system prompt
n (multiple completions)	Not supported	Use multiple requests
logprobs	Not supported	N/A

Side-by-Side Code Comparison

# === OpenAI ===
from openai import OpenAI
client = OpenAI()
response = client.chat.completions.create(
    model="gpt-4",
    messages=[
        {"role": "system", "content": "You are helpful."},
        {: , : }
    ],
    max_tokens=,
    temperature=
)
text = response.choices[].message.content


 anthropic
client = anthropic.Anthropic()
response = client.messages.create(
    model=,
    system=,           
    messages=[
        {: , : }
    ],
    max_tokens=,                     
    temperature=
)
text = response.content[].text