Gemini 3.8 Flash vs GPT-6 Astra Comparison

// Gemini 3.8 Flash - agentic coding task via google-genai SDK (Python)
from google import genai

# GEMINI_API_KEY is read from the environment by default
client = genai.Client()

interaction = client.interactions.create(
    model="gemini-3.8-flash",
    input=(
        "You are an autonomous coding agent. Run the test suite, "
        "fix the first failing test, and report a one-line summary."
    ),
    generation_config={
        # allowed: low | medium | high (minimal is rejected)
        "thinking_level": "high"
    },
)

print(interaction.output_text)

# Streaming variant for long-horizon agent loops
stream = client.interactions.create(
    model="gemini-3.8-flash",
    input="Refactor the auth module and validate with the linter.",
    stream=True,
)
for event in stream:
    print(event)

// GPT-6 Astra - high-effort reasoning task via OpenAI SDK (Python)
import os
from openai import OpenAI

client = OpenAI(api_key=os.environ["OPENAI_API_KEY"])

response = client.responses.create(
    model="gpt-6-astra",
    input=(
        "You are an autonomous coding agent working on a large refactor. "
        "Plan the steps, execute them, verify the result independently, "
        "and only report done once verification passes."
    ),
    reasoning={"effort": "high"},  # allowed: low | medium | high | xhigh | max
    max_output_tokens=4096,
)

print(response.output_text)

# Codex CLI equivalent (config.toml): select the model explicitly since
# the CLI now surfaces migration prompts for older models
# [profile.default]
# model = "gpt-6-astra"
# model_reasoning_effort = "high"