What does a code review bot cost per month with an AI API?

On current list prices, GPT-6 Luna is the cheapest model we track for this workload at $21.45 per month, while the most expensive costs $2,145 — a 100× spread. Every model’s exact figure is in the table above, verified November 7, 2026.

Which AI model is cheapest for a code review bot?

GPT-6 Luna charges $0.10 input / $0.50 per 1M tokens, which works out to $0.0007 per request and $21.45 per month for this workload. Check the capability column too — the cheapest models can score lower on benchmarks, and a mid-priced model is often the better deal.

How is the monthly cost calculated?

Each request splits the 5,000 input tokens into fresh and cached tokens, multiplies each by the model’s rate, then adds 700 output tokens at the output rate: cost = (fresh input × input rate + cached input × cached rate + output × output rate) ÷ 1,000,000. The per-request cost is then multiplied by 30,000 requests per month.

How accurate is this estimate?

It uses each provider’s standard list prices, verified November 7, 2026, including published cached-input rates and long-context thresholds. It excludes cache-write surcharges, batch discounts, taxes and volume deals — heavy users can usually negotiate below list.

Code review bot: AI API cost per month

30,000 pull-request reviews a month, ~5,000 input tokens each (30% cached repository context) and ~700 output tokens.

Requests

30,000

per month

Tokens per request

5K in / 1K out

171M tokens per month

Cheapest model

$21.45

GPT-6 Luna per month

Priciest model

$2,145

GPT-6 Astra per month

What code review bot costs on every model

Model	Per request	Per month	Capability (ECI)
GPT-6 Luna$0.10 in / $0.50 out per 1M tokens	$0.0007	$21.45	156.3
Claude Haiku 5.5$0.10 in / $0.50 out per 1M tokens	$0.0007	$21.45	159.0
GPT-5.6 Luna$0.20 in / $1.20 out per 1M tokens	$0.0016	$47.10	156.3
DeepSeek V4.1 Flash$0.30 in / $1.20 out per 1M tokens	$0.0019	$56.97	155.6
Gemini 3.5 Flash-Lite$0.30 in / $2.50 out per 1M tokens	$0.0028	$85.35	145.2
Gemini 2.5 Flash$0.30 in / $2.50 out per 1M tokens	$0.0028	$85.35	140.8
Gemini 3.8 Flash$0.75 in / $3.75 out per 1M tokens	$0.0054	$160.88	157.2
Gemini 3.6 Flash$0.75 in / $3.75 out per 1M tokens	$0.0054	$160.88	154.2
Grok 4.3$1.25 in / $2.50 out per 1M tokens	$0.0064	$192.75	—
GPT-6.1 Terra$1.00 in / $5.00 out per 1M tokens	$0.0071	$212.25	—
Claude Haiku 4.5$1.00 in / $5.00 out per 1M tokens	$0.0072	$214.50	142.4
DeepSeek V4 Pro$1.32 in / $3.96 out per 1M tokens	$0.0075	$223.74	155.3
Gemini 2.5 Pro$1.25 in / $10.00 out per 1M tokens	$0.01	$346.88	145.3
Grok 4.7$2.00 in / $6.00 out per 1M tokens	$0.01	$358.50	154.4
Grok 4.6$2.00 in / $6.00 out per 1M tokens	$0.01	$358.50	156.3
GPT-6.1 Sol$2.00 in / $10.00 out per 1M tokens	$0.01	$424.50	166.3
Gemini 4 Argon$2.00 in / $10.00 out per 1M tokens	$0.01	$424.50	164.6
GPT-6 Sol$2.00 in / $10.00 out per 1M tokens	$0.01	$429.00	162.6
Claude Sonnet 5.5$2.00 in / $10.00 out per 1M tokens	$0.01	$429.00	164.4
Claude Sonnet 5$2.00 in / $10.00 out per 1M tokens	$0.01	$429.00	156.4
GPT-5.6 Terra$2.00 in / $12.00 out per 1M tokens	$0.02	$471.00	159.4
Gemini 3.1 Pro$2.00 in / $12.00 out per 1M tokens	$0.02	$471.00	154.7
Claude Opus 5.5$4.00 in / $20.00 out per 1M tokens	$0.03	$849.00	166.8
GPT-5.6 Sol$4.00 in / $20.00 out per 1M tokens	$0.03	$858.00	161.7
Claude Opus 5$5.00 in / $25.00 out per 1M tokens	$0.04	$1,073	162.6
Claude Fable 5.1$10.00 in / $50.00 out per 1M tokens	$0.07	$2,111	164.7
GPT-6 Astra$10.00 in / $50.00 out per 1M tokens	$0.07	$2,145	166.4

ECI = Epoch Capabilities Index (Epoch AI, CC BY 4.0). A dash means the model is not yet rated. See the full leaderboard.

How this estimate works

The workload above — 30,000 requests a month, 5,000 input tokens and 700 output tokens each, with 30% of input tokens served from the prompt cache— is run through every model’s official price list. Where a provider publishes a long-context threshold and this workload’s prompts exceed it, the higher long-context rate applies automatically.

Run your own numbers in the cost calculator, or see the full methodology. If two models are close in price, compare them directly: GPT-6 Luna vs Claude Haiku 5.5.

Other workload estimates

Frequently asked questions

What does a code review bot cost per month with an AI API?: On current list prices, GPT-6 Luna is the cheapest model we track for this workload at $21.45 per month, while the most expensive costs $2,145 — a 100× spread. Every model’s exact figure is in the table above, verified November 7, 2026.
Which AI model is cheapest for a code review bot?: GPT-6 Luna charges $0.10 input / $0.50 per 1M tokens, which works out to $0.0007 per request and $21.45 per month for this workload. Check the capability column too — the cheapest models can score lower on benchmarks, and a mid-priced model is often the better deal.
How is the monthly cost calculated?: Each request splits the 5,000 input tokens into fresh and cached tokens, multiplies each by the model’s rate, then adds 700 output tokens at the output rate: cost = (fresh input × input rate + cached input × cached rate + output × output rate) ÷ 1,000,000. The per-request cost is then multiplied by 30,000 requests per month.
How accurate is this estimate?: It uses each provider’s standard list prices, verified November 7, 2026, including published cached-input rates and long-context thresholds. It excludes cache-write surcharges, batch discounts, taxes and volume deals — heavy users can usually negotiate below list.