Codex Plugin Model Aliases: Understanding the Spark Alias Mapping

The Codex plugin supports exactly one model alias—spark—which internally maps to the full model identifier gpt-5.3-codex-spark when invoked via the CLI.

The openai/codex-plugin-cc repository provides a command-line interface for interacting with OpenAI's Codex models. When working with Codex plugin model aliases, you can use the short spark identifier rather than typing the complete model name, simplifying task execution while maintaining precise model targeting.

Supported Model Aliases

The plugin defines exactly one model alias within its source code. This alias serves as a shorthand reference that the CLI resolves to a specific Codex model version.

The Spark Alias Implementation

In plugins/codex/scripts/codex-companion.mjs, line 72 defines the alias mapping:

const MODEL_ALIASES = new Map([["spark", "gpt-5.3-codex-spark"]]);

This Map structure ensures that whenever you specify --model spark, the plugin substitutes gpt-5.3-codex-spark before sending the request to the underlying API.

How to Use Model Aliases in Commands

You can invoke the Codex plugin using either the alias or the full model identifier. Both approaches trigger identical behavior.

Using the Alias

node scripts/codex-companion.mjs task --model spark --effort low "diagnose the failing test"

Using the Full Model Name

node scripts/codex-companion.mjs task --model gpt-5.3-codex-spark --effort low "diagnose the failing test"

The first command maps spark to gpt-5.3-codex-spark internally, while the second bypasses the alias resolution step.

Implementation and Testing

The alias system is validated in tests/commands.test.mjs, which asserts that the spark input correctly resolves to gpt-5.3-codex-spark. The README.md documentation also references the --model flag and mentions the spark alias for user guidance.

According to the openai/codex-plugin-cc source code, no additional aliases are currently defined in the MODEL_ALIASES Map, making spark the exclusive shorthand available for model selection.

Summary

• The Codex plugin model aliases system contains only one entry: spark.
• The alias maps to gpt-5.3-codex-spark as defined in plugins/codex/scripts/codex-companion.mjs.
• You can use --model spark interchangeably with --model gpt-5.3-codex-spark in CLI commands.
• The mapping is implemented via a JavaScript Map and verified by the test suite in tests/commands.test.mjs.

Frequently Asked Questions

What model aliases are supported by the Codex plugin?

The Codex plugin supports exactly one model alias: spark. This alias provides a shorthand reference to the full model identifier gpt-5.3-codex-spark and is defined in the MODEL_ALIASES Map within the CLI script.

What is the full model name for the spark alias?

The spark alias maps to gpt-5.3-codex-spark. When you specify --model spark in your command, the plugin internally substitutes this full identifier before processing the request.

Where is the model alias mapping defined in the source code?

The mapping is defined in plugins/codex/scripts/codex-companion.mjs at line 72, where a JavaScript Map object associates the string "spark" with "gpt-5.3-codex-spark".

Can I use the full model name instead of the spark alias?

Yes, you can explicitly specify --model gpt-5.3-codex-spark instead of using the spark alias. Both methods invoke the same underlying model; the alias simply provides a shorter, more memorable command-line option.

{
  "mcpServers": {
    "instagit": {
      "command": "npx",
      "args": ["-y", "instagit@latest"]
    }
  }
}