← Back to context Comment by mobelkh 8 days ago can't imagine rewriting a runtime to be easier than a coding harness 2 comments mobelkh Reply usef- 8 days ago You might be surprised. Runtimes can be easier to test than UI for AI, and the bun rewrite was almost line-for-line translation, whereas CC likely uses many more libraries that cannot be ported directly.The major open harnesses are in the ~800k lines of code size ( https://simonwillison.net/2026/Jul/15/grok-build/ ) and CC is the oldest and quite-likely largest judging by features. pdimitar 8 days ago It's really not about a PL runtime vs. an agent harness, it's about how spaghetti and complex the code is. I do get your point though.
usef- 8 days ago You might be surprised. Runtimes can be easier to test than UI for AI, and the bun rewrite was almost line-for-line translation, whereas CC likely uses many more libraries that cannot be ported directly.The major open harnesses are in the ~800k lines of code size ( https://simonwillison.net/2026/Jul/15/grok-build/ ) and CC is the oldest and quite-likely largest judging by features.
pdimitar 8 days ago It's really not about a PL runtime vs. an agent harness, it's about how spaghetti and complex the code is. I do get your point though.
You might be surprised. Runtimes can be easier to test than UI for AI, and the bun rewrite was almost line-for-line translation, whereas CC likely uses many more libraries that cannot be ported directly.
The major open harnesses are in the ~800k lines of code size ( https://simonwillison.net/2026/Jul/15/grok-build/ ) and CC is the oldest and quite-likely largest judging by features.
It's really not about a PL runtime vs. an agent harness, it's about how spaghetti and complex the code is. I do get your point though.