Claude (Anthropic) vs ChatGPT (OpenAI) Comparison

// Terminal integration with Claude Code (bash)
# Install Claude Code
npm install -g @anthropic-ai/claude-code

# Project analysis
claude "Find and fix memory leaks in this project"

# File-based operation
claude "Analyze the file portfolio/src/lib/firestore.ts,
  list the issues causing unnecessary re-renders"

# Git integration
claude "Review the last 5 commits, any breaking changes?"

# Writing tests
claude "Write a comprehensive test suite for CartViewModel using XCTest"

# Example Claude API usage (Swift)
import Foundation

struct ClaudeClient {
    let apiKey: String
    let baseURL = URL(string: "https://api.anthropic.com/v1/messages")!

    func complete(prompt: String, maxTokens: Int = 4096) async throws -> String {
        var request = URLRequest(url: baseURL)
        request.httpMethod = "POST"
        request.setValue("application/json", forHTTPHeaderField: "Content-Type")
        request.setValue(apiKey, forHTTPHeaderField: "x-api-key")
        request.setValue("2023-06-01", forHTTPHeaderField: "anthropic-version")

        let body: [String: Any] = [
            "model": "claude-opus-4-7",
            "max_tokens": maxTokens,
            "messages": [["role": "user", "content": prompt]]
        ]
        request.httpBody = try JSONSerialization.data(withJSONObject: body)

        let (data, _) = try await URLSession.shared.data(for: request)
        let response = try JSONDecoder().decode(ClaudeResponse.self, from: data)
        return response.content.first?.text ?? ""
    }
}

// OpenAI API - GPT-4o integration in Swift
import Foundation

struct OpenAIClient {
    let apiKey: String
    let baseURL = URL(string: "https://api.openai.com/v1/chat/completions")!

    struct Message: Codable {
        let role: String
        let content: String
    }

    func chat(messages: [Message], model: String = "gpt-5") async throws -> String {
        var request = URLRequest(url: baseURL)
        request.httpMethod = "POST"
        request.setValue("application/json", forHTTPHeaderField: "Content-Type")
        request.setValue("Bearer \\(apiKey)", forHTTPHeaderField: "Authorization")

        let body: [String: Any] = [
            "model": model,
            "messages": messages.map { ["role": $0.role, "content": $0.content] },
            "temperature": 0.7,
            "max_tokens": 4096
        ]
        request.httpBody = try JSONSerialization.data(withJSONObject: body)

        let (data, _) = try await URLSession.shared.data(for: request)
        let response = try JSONDecoder().decode(ChatResponse.self, from: data)
        return response.choices.first?.message.content ?? ""
    }

    // Vision API - analyzing code from an image
    func analyzeScreenshot(imageBase64: String) async throws -> String {
        let messages: [[String: Any]] = [[
            "role": "user",
            "content": [
                ["type": "text", "text": "Convert this UI screenshot to SwiftUI"],
                ["type": "image_url", "image_url": ["url": "data:image/png;base64,\\(imageBase64)"]]
            ]
        ]]
        // Send the API request...
        return "SwiftUI code goes here"
    }
}