---
type: source
title: "Programming fundamentally changed in December 2025 — coding agents basically didn't work before and basically work since"
author: "Andrej Karpathy (@karpathy)"
twitter_id: "33836629"
url: https://x.com/karpathy/status/2026731645169185220
date: 2026-02-25
domain: ai-alignment
secondary_domains: [teleological-economics]
format: tweet
status: processed
priority: medium
tags: [coding-agents, ai-capability, phase-transition, software-development, disruption]
processed_by: theseus
processed_date: 2026-03-11
claims_extracted: ["coding-agents-crossed-usability-threshold-december-2025-when-models-achieved-sustained-coherence-across-complex-multi-file-tasks.md"]
enrichments_applied: ["as AI-automated software development becomes certain the bottleneck shifts from building capacity to knowing what to build making structured knowledge graphs the critical input to autonomous systems.md", "the progression from autocomplete to autonomous agent teams follows a capability-matched escalation where premature adoption creates more chaos than value.md"]
extraction_model: "anthropic/claude-sonnet-4.5"
extraction_notes: "High-signal source from authoritative voice. Single claim extracted identifying December 2025 as phase transition point for coding agent usability. Three enrichments to existing claims about AI automation, deployment gaps, and capability-matched adoption. Confidence rated experimental (single expert observation, high credibility but not systematic evidence). The 'asterisks' Karpathy mentions are preserved as acknowledged limitations in the Challenges section."
---

## Content

It is hard to communicate how much programming has changed due to AI in the last 2 months: not gradually and over time in the "progress as usual" way, but specifically this last December. There are a number of asterisks but imo coding agents basically didn't work before December and basically work since - the models have significantly higher quality, long-term coherence and tenacity and they can power through large and long tasks, well past enough that it is extremely disruptive to the default programming workflow.

## Agent Notes

**Why this matters:** 37K likes — Karpathy's most viral tweet in this dataset. This is the "phase transition" observation from the most authoritative voice in AI dev tooling. December 2025 as the inflection point for coding agents.

**KB connections:** Supports [[as AI-automated software development becomes certain the bottleneck shifts from building capacity to knowing what to build]]. Relates to [[the gap between theoretical AI capability and observed deployment is massive across all occupations]] — but suggests the gap is closing fast for software specifically.

**Extraction hints:** Claim candidate: coding agent capability crossed a usability threshold in December 2025, representing a phase transition not gradual improvement. Evidence: Karpathy's direct experience running agents on nanochat.

**Context:** This tweet preceded the autoresearch project by ~10 days. The 37K likes suggest massive resonance across the developer community. The "asterisks" he mentions are important qualifiers that a good extraction should preserve.


## Key Facts
- Karpathy tweet received 37K likes (February 2026)
- Tweet preceded autoresearch project by ~10 days
- Karpathy tested agents on nanochat project
