# Putting models to the secure coding test: Plan vs default mode

DevFeed: [Putting models to the secure coding test: Plan vs default mode](<https://devfeed.tech/articles/putting-models-to-the-secure-coding-test-plan-vs-default-mode-8297.md>)

Original publisher: [Read original article](<https://securitylabs.datadoghq.com/articles/putting-models-to-the-secure-coding-test-plan-vs-default-mode/>)

Author: Kennedy Toomey

Published: 2026-08-19T00:00:00Z

Content type: article

Language: en

Sources: [Datadog Security Labs](<https://devfeed.tech/sources/datadog-security-labs.md>)

Topics: [AI-assisted coding](<https://devfeed.tech/topics/ai-assisted-coding.md>), [Application Security](<https://devfeed.tech/topics/application-security.md>), [code security](<https://devfeed.tech/topics/code-security.md>), [Code quality](<https://devfeed.tech/topics/code-quality.md>), [Vulnerabilities](<https://devfeed.tech/topics/vulnerabilities.md>), [Claude](<https://devfeed.tech/topics/claude.md>), [cursor](<https://devfeed.tech/topics/cursor.md>), [codex](<https://devfeed.tech/topics/codex.md>)

Tags: [application-security](<https://devfeed.tech/tags/application-security.md>), [claude](<https://devfeed.tech/tags/claude.md>), [code-quality](<https://devfeed.tech/tags/code-quality.md>), [code-security](<https://devfeed.tech/tags/code-security.md>), [codex](<https://devfeed.tech/tags/codex.md>), [command-line](<https://devfeed.tech/tags/command-line.md>), [cursor](<https://devfeed.tech/tags/cursor.md>), [supply-chain](<https://devfeed.tech/tags/supply-chain.md>), [vulnerabilities](<https://devfeed.tech/tags/vulnerabilities.md>)

## AI overview

This article describes an experiment comparing plan mode with default mode for secure code generation. The author tested Sonnet 5, Composer 2.5, and GPT 5.5 through Claude, Cursor, and Codex, using security and code-quality analysis to assess the results.

## Source excerpt

We tested Sonnet 5, Composer 2.5, and GPT 5.5 in plan mode and default mode to see whether plan mode produces measurably more secure code.