anth-migration-deep-dive

# 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 ```python # === OpenAI === from openai import OpenAI client = OpenAI() response = client.chat.completions.create( model="gpt-4", messages=[ {"role": "system", "content": "You are helpful."}, {"role": "user", "content": "Hello"} ], max_tokens=1024, temperature=0.7 ) text = response.choices[0].message.content # === Anthropic === import a...