$2.28 for 100 Code Reviews: An Illustrative Receipt

01 / A $2.28 review budget, not a pricing promise

You can budget for a coding assistant without pretending every pull request costs the same. Start with a receipt: tokens sent, tokens returned, follow-up requests, and retries. Then keep human review time separate from the API bill.

The example below covers 100 pull requests. It uses illustrative rates of $1 per million input tokens and $5 per million output tokens. These are arithmetic assumptions, not quoted CheapRelay prices or a claim about any particular model. Substitute the current rates for your selected model before funding the workflow.

02 / The receipt: 130 requests across 100 pull requests

Assume each initial review sends 12,000 input tokens and returns 1,500 output tokens. That input budget must include instructions, the diff, relevant source code, and any tool output. Twenty pull requests need a smaller follow-up. Another ten require one full-size retry.

• ■ 100 initial reviews: 1,200,000 input tokens × $1/million = $1.20; 150,000 output tokens × $5/million = $0.75. Subtotal: $1.95.
• ■ 20 targeted follow-ups: 80,000 input tokens = $0.08; 10,000 output tokens = $0.05. Subtotal: $0.13.
• ■ 10 full-size retries: 120,000 input tokens = $0.12; 15,000 output tokens = $0.075. Subtotal: $0.195.
• ■ Total: 1,400,000 input tokens and 175,000 output tokens across 130 requests. Calculated cost: $2.275, or $2.28 rounded to cents.
• ■ Average API cost per pull request: $0.02275, approximately 2.3 cents.

This receipt assumes no cache reads or writes and excludes taxes, currency conversion, CI infrastructure, and human time. Actual charges depend on actual usage and applicable rates. A coding assistant that repeatedly reads files or runs tools can exceed this request budget quickly.

03 / Give the assistant a review packet, not the repository

Build a compact packet containing the change description, diff, relevant surrounding functions, and test results. Include repository guidance that affects correctness, such as authorization rules or transaction boundaries. Leave unrelated files out.

Ask for correctness and security findings first. Require a file location, failure scenario, and suggested verification for each finding. Tell the assistant to skip cosmetic preferences unless they violate an explicit project rule. Request no more than five findings; a short list is cheaper to generate and easier to verify.

A practical instruction is: Review only the supplied changes. Report actionable defects with evidence. Identify missing context instead of inventing behavior. Do not edit files or run commands without approval. Return a brief explanation when no actionable issue is found.

04 / Put a $3 ceiling around the $2.28 estimate

At these assumed rates, a $3 API allowance leaves $0.725 above the calculated receipt, roughly 32% headroom. That is a planning cushion, not a guaranteed maximum. Enforce the ceiling in your wrapper or CI workflow using recorded usage, request limits, and a stop condition.

• ■ Allow one initial review per pull request revision.
• ■ Require approval for additional repository exploration.
• ■ Cap response length and tool-call iterations.
• ■ Stop automatic retries after one attempt; investigate repeated failures.
• ■ Record input, output, cache reads, cache writes, and cost for every request.

When caching is available, calculate its read and write charges separately. Do not count cached tokens as free. Also inspect conversation history: resending an entire review thread can erase the savings from a smaller follow-up prompt.

05 / Use CheapRelay without turning the budget into a subscription

CheapRelay offers pay-as-you-go API access with no monthly fee or subscription. Billing follows real token usage, including cache reads and writes. Its OpenAI-compatible routes use https://api.cheapapirelay.com/v1, making an existing SDK-based review script a practical starting point.

Sign up for CheapRelay, check the current model rates, and run a ten-pull-request pilot before expanding the budget. Compare the actual receipt with this estimate. Keep the assistant advisory: a cheap review is useful only when a developer verifies its findings and remains responsible for the merge.