7h ago

Greg Kamradt, President of the ARC Prize Foundation, adds a Codex harness to the ARC-AGI-3 agents repository to enable ablation tests across four tool configurations

Tests compare no tools, scratchpad, code execution, and combined setups.

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Original post

We're adding a codex harness added to our ARC-AGI-3 agents repo We're doing ablations to find what tool helps the most * Codex - No tools * Codex - Scratchpad only (read/write) * Codex - Code only (read/write/execute .py) * Codex - Scratchpad + Code My guess is scratchpad will account for the majority of the perf increase. Code will help, but only on certain games that are logic heavy (instead of exploration heavy) Example scratch pad screenshot

8:38 AM · May 21, 2026 View on X

@GregKamradt how is the scratchpad define here? something like mentioning in the prompt that it can write/read/delete a scratchpad.md file?

Greg KamradtGreg Kamradt@GregKamradt

We're adding a codex harness added to our ARC-AGI-3 agents repo We're doing ablations to find what tool helps the most * Codex - No tools * Codex - Scratchpad only (read/write) * Codex - Code only (read/write/execute .py) * Codex - Scratchpad + Code My guess is scratchpad will account for the majority of the perf increase. Code will help, but only on certain games that are logic heavy (instead of exploration heavy) Example scratch pad screenshot

3:38 PM · May 21, 2026 · 3.1K Views
5:34 PM · May 21, 2026 · 169 Views

@GregKamradt ok perfect, i was going to say scratchpad dir would probably be even better than just a .md file

btw we found on our automated speedrun experiment that how scratchpad is used depends quite a lot on the model, would be curious if you find similar results on arc agi 👀

Greg KamradtGreg Kamradt@GregKamradt

@eliebakouch Ya, basically access to a working directory just for that game run with ability to read/write Md files. External memory W/o the ability to write code

5:40 PM · May 21, 2026 · 109 Views
5:45 PM · May 21, 2026 · 65 Views

@eliebakouch Ya, basically access to a working directory just for that game run with ability to read/write Md files. External memory

W/o the ability to write code

elieelie@eliebakouch

@GregKamradt how is the scratchpad define here? something like mentioning in the prompt that it can write/read/delete a scratchpad.md file?

5:34 PM · May 21, 2026 · 169 Views
5:40 PM · May 21, 2026 · 109 Views

@eliebakouch Fascinating - will do

elieelie@eliebakouch

@GregKamradt ok perfect, i was going to say scratchpad dir would probably be even better than just a .md file btw we found on our automated speedrun experiment that how scratchpad is used depends quite a lot on the model, would be curious if you find similar results on arc agi 👀

5:45 PM · May 21, 2026 · 65 Views
5:52 PM · May 21, 2026 · 35 Views