Aider + DeepSeek is the cheapest way to get frontier-class AI coding. DeepSeek Chat costs $0.27/1M input tokens — that’s 55x cheaper than Claude Opus. Here’s how to set it up.

Update (April 24, 2026): DeepSeek V4 is now available. Use deepseek-v4-pro or deepseek-v4-flash model IDs in Aider. V4-Pro scores 80.6% on SWE-bench, V4-Flash at $0.14/$0.28 per 1M tokens. See V4 Aider setup for the updated guide.

Setup

pip install aider-chat
export DEEPSEEK_API_KEY="your-key"  # Get from platform.deepseek.com
cd your-project
aider --model deepseek/deepseek-chat

That’s it. You’re coding with a frontier model for pennies.

Recommended configuration

Use DeepSeek Chat for routine work and DeepSeek Reasoner for complex problems:

# .aider.conf.yml
model: deepseek/deepseek-chat
weak-model: deepseek/deepseek-chat
edit-format: diff
auto-commits: true

For hard problems, switch mid-session:

/model deepseek/deepseek-reasoner

Cost breakdown

Usage	Tokens/day	Daily cost	Monthly cost
Light (1hr)	~200K	$0.05	~$1.50
Moderate (3hr)	~600K	$0.16	~$5
Heavy (6hr)	~1.5M	$0.40	~$12

Even heavy use stays under $15/month — vs $20/month for Claude Pro or Cursor.

Tips for best results with DeepSeek

1. Use diff edit format — DeepSeek handles diffs well and it saves tokens
2. Be specific in prompts — DeepSeek is less forgiving of vague instructions than Claude
3. Use --read for context files — saves tokens on files that don’t need editing
4. Switch to Reasoner for debugging — the reasoning model is better at tracing bugs
5. Combine with local Codestral for autocomplete — free + cheap = best value

DeepSeek vs other cheap options

Model via Aider	Input cost	Quality
DeepSeek Chat	$0.27/1M	Very good
Qwen 3.5 Flash	$0.065/1M	Good
GLM Coding Plan	$3/mo flat	Excellent
Local via Ollama	Free	Good (model-dependent)

Related: Aider Complete Guide · Cheapest AI Coding Setup 2026 · Best Free AI APIs 2026