Why Vibe Coding Burns Tokens Faster Than You Type
Vibe coding is an agent loop, not a chat. Every turn re-sends the files the agent is working on:
| Codebase size | Context / turn | 50-turn session | Typical MVP total |
|---|---|---|---|
| Small (5 files, ~500 lines) | ~8K tokens | 400K tokens | 10–20M |
| Medium (12 files, ~2,000 lines) | ~30K tokens | 1.5M tokens | 20–35M |
| Large (30 files, ~5,000 lines) | ~70K tokens | 3.5M tokens | 40–70M |
Add refactors, failed builds, and the classic "fix this error" retry loop, and a real MVP lands between 15 and 40 million tokens. The harness (Cursor, Bolt, v0, OpenCode) decides how much context each turn carries — that choice matters more than the model price.
The Per-App Price Table
A 25M-token MVP (70% input / 30% output — the realistic agent mix), priced at verified 2026-08-28 rates. This is the raw API cost, before harness subscriptions and markups:
| Model | Rate ($/1M in, out) | Input (17.5M) | Output (7.5M) | Per app |
|---|---|---|---|---|
| Claude Sonnet 5 | $2 / $10 | $35 | $75 | $110 |
| GPT-5.6 Terra | $2 / $12 | $35 | $90 | $125 |
| Gemini 3.7 Flash | $1.50 / $6 | $26 | $45 | $71 |
| DeepSeek V4 Pro | $1.32 / $3.96 | $23 | $30 | $53 |
| GPT-5.6 Luna | $0.20 / $1.20 | $3.50 | $9 | $12.50 |
| DeepSeek V4 Flash (off-peak) | $0.22 / $0.66 | $3.90 | $5 | $8.90 |
The same app costs $110 on Claude Sonnet 5 and $8.90 on DeepSeek V4 Flash off-peak — a 12× difference with zero changes to how you prompt. Note the pattern: harness subscriptions ($20-200/mo) are a rounding error next to token spend on flagship models.
Month of Vibe Coding: The Realistic Budget
Add a $20 Cursor subscription and the budget path is $52/month all-in — less than half of what most founders assume vibe coding costs. The premium path is real too: if you ship with a flagship for the final polish week, the blended number sits around $200-300/month.
The 6 Rules of Cheap Vibe Coding
Default to a budget or balanced model
Build on DeepSeek V4 Flash / GPT-5.6 Luna / Gemini 3.7 Flash. Escalate to a flagship only for specific hard sessions — most of the work is CRUD the budget tiers handle fine.
Turn off full-repo context
OpenCode, Cursor and friends offer repo-wide context modes that quadruple per-turn tokens. Point the agent at the files that matter.
Cap max_tokens per turn
A runaway 4,000-token completion on Sonnet 5 costs 8× the input of the whole turn. Harnesses let you cap this; use it.
Batch the "fix this error" loop
Copy the error, fix it yourself first, or give the agent the exact log line — every blind retry re-bills the full context.
Use off-peak hours on DeepSeek
Night sessions bill at half price automatically. Shift the bulk generation to late evening and save 50% on that model.
Track it like a budget
If you use your own API key, export the month into Bill Doctor and see exactly which app ate the tokens — then fix that app's context usage.
Frequently Asked Questions
How much does vibe coding cost per app?
A small MVP typically burns 15-40 million tokens of agent traffic before it ships. On Claude Sonnet 5 that is roughly $30-90 of raw API tokens; on DeepSeek V4 Flash off-peak it is $5-15; on GPT-5.6 Luna about $4-12. Subscriptions and harness markups are on top.
Does Cursor, Bolt or v0 include token costs in the subscription?
No — the subscription is access to the harness (and some included quota). Heavy vibe-coding sessions exceed even premium quotas fast, then you either wait, pay per-usage, or burn your own API key. Token math is unavoidable.
Which model should I vibe-code with to keep costs low?
For CRUD apps and UI work, a balanced model like GPT-5.6 Terra or Gemini 3.7 Flash gives quality with a sane bill. Budget tiers (DeepSeek V4 Flash, GPT-5.6 Luna) shine for bulk scaffolding; keep a flagship in reserve for hard debugging sessions.
Why does vibe coding burn so many tokens?
Every agent turn re-sends the whole file context: a 2,000-line codebase is ~25,000-40,000 tokens of context per turn. A 50-turn session on a codebase that size bills over a million tokens even though you only typed 30 sentences.
How do I vibe-code without a surprise bill?
Use a budget model by default, turn off the giant-context mode, cap max_tokens per turn, and track session token counts in the harness dashboard. Our AI Cost Wrapped recap shows where the month went if you use a BYOK setup.