TL;DR — For coding agents, the cheapest LLM API is the one that picks a different model per call — typical blended cost is 60-80% less than always-Sonnet, with no quality regression. Direct providers (Anthropic, OpenAI) are most expensive per token. Cloudflare Workers AI is cheapest hosted. jusInfer auto-routes to the right tier for each step.
The cheapest LLM API for coding agents in 2026, ranked
If you're running an AI coding agent — Claude Code, Cursor, Aider, OpenCode, Cline — your monthly bill is almost certainly bigger than it needs to be. The cheapest API for a chat is not the cheapest API for an agent, because agents make 5-20 calls per task with long contexts. This post compares actual per-task cost, not headline per-token rate, and tells you what to switch to.
What "cheap" means for a coding agent
A typical agent task — "refactor this function to use async/await and update the tests" — generates roughly:
- 5,000–20,000 prompt tokens (source files + history)
- 500–3,000 completion tokens (diff + reasoning)
- 5–15 round trips (read file → propose edit → run tests → iterate)
That's 50k–250k tokens per task. At Sonnet 4.5 rates ($3 / 1M input, $15 / 1M output), a single task is $0.20–$1.20. Hundred tasks a day, you're at $20–$120/day per engineer. The optimization isn't the per-token rate — it's routing the easy steps to a cheaper model.
The 2026 price grid (input / output, USD per 1M tokens)
| Provider | Top model | Mid model | Cheap model |
|---|---|---|---|
| Anthropic direct | Sonnet 4.5: $3 / $15 | Haiku 4.5: $1 / $5 | — |
| OpenAI direct | GPT-5: $5 / $20 | GPT-5-mini: $0.40 / $1.60 | GPT-5-nano: $0.05 / $0.40 |
| Together.ai | Llama 4 Maverick: $0.88 / $0.88 | Qwen3 Coder 480B: $0.90 / $1.20 | Llama 4 Scout 17B: $0.18 / $0.59 |
| Fireworks | Same as Together-ish | DeepSeek V4: $0.27 / $1.10 | Llama 4 8B: $0.10 / $0.30 |
| Cloudflare Workers AI | Kimi K2.6: $0.50 / $1.50 | Qwen3 8B: $0.10 / $0.20 | Llama 3.2 1B: $0.02 / $0.05 |
| OpenRouter | Aggregator — passes through + 5% | same | same |
| jusInfer | Auto-routed — typical $0.20–$1.00 / 1M blended |
Prices as of May 2026. Verify on each provider's site before relying on these.
The honest ranking
1. Self-hosted Llama 4 8B on a single H100 — cheapest if your time is free
For batch overnight runs, this is unbeatable. For interactive coding agents, you're paying $2/hour for an idle GPU 90% of the time. Not realistic unless you're already an infra team.
2. Cloudflare Workers AI (@cf/... models) — cheapest hosted
$0.10–$0.50 / 1M tokens for the open-weights catalog. Edge-local, low latency. Smaller model selection. Coverage gaps for vision and very-long context.
3. Fireworks / Together — cheapest big-catalog hosting
Wide model selection, no minimums, fast. ~30-50% cheaper than Anthropic/OpenAI direct for equivalent capability via open weights.
4. OpenRouter — convenience tax
Same prices as the underlying provider + a small markup. Good if you want one bill across many providers and don't want to think about routing.
5. jusInfer — cheapest if you're running an agent
Same model menu, but the system picks per call. A read-only file inspection goes to an 8B model for $0.02. A multi-file refactor goes to Sonnet for $0.30. Average blended cost is 60–80% less than always-Sonnet, with the same task-completion rate. We benchmark this monthly on a fixed task suite.
6. Anthropic / OpenAI direct — most expensive per token, simplest to set up
Top-tier capability. If your agent only ever needs Sonnet or GPT-5 and the bill doesn't bother you, go direct.
A real example
A team running Cursor with default Sonnet 4.5 settings, 8 engineers, 4 hours/day each, was spending ~$2,800/month. Switching the Cursor custom base URL to jusInfer (5 minutes of config), no other change, dropped them to ~$680/month over the next 30 days — same diff quality across their internal rubric. The savings came from jusInfer routing trivial completions (lint fixes, type annotations, single-line edits) to Qwen3 8B and reserving Sonnet for the hard cases.
We have a full case-study writeup with the methodology — email hello@jusinfer.com if you want a copy.
Setup, by tool
- Use jusInfer with Claude Code
- Use jusInfer with OpenCode
- OpenAI-compatible drop-in (Cursor, Aider, Cline, Continue, Goose)
Caveats and biases
- We're jusInfer. Our number is rosier than competitors'. That said, the methodology (50 fixed real-world tasks, evaluated by 3 senior engineers blind to provider) is in our docs and you can reproduce it with our trial credits.
- Prices change monthly. Anything written here is stale within 90 days. Check primary sources.
- "Cheapest" for coding is not "cheapest" for chat, not "cheapest" for RAG, not "cheapest" for vision. Read your own logs before picking.
Related reading
- OpenRouter alternatives in 2026
- What is an inference endpoint?
- Why your Cursor bill is too high — and three ways to cut it
- API reference
Raw markdown: /blog/cheapest-llm-api-for-coding-2026.md