# One API key, two GLM models: what routing easy steps to GLM-5.3-Flash does to the bill (prices checked 2026-10-27)

> Source: <https://dev.to/iteracompute/one-api-key-two-glm-models-what-routing-easy-steps-to-glm-53-flash-does-to-the-bill-prices-mo>
> Published: 2026-10-27 02:30:40+00:00

This is IteraCompute, so treat this as a disclosed write-up from one provider, not a neutral ranking. Every price below is a list price in USD per 1M tokens, checked on 2026-10-27 from the providers' pricing pages or OpenRouter's endpoint list. Prices change often, so check them again before you commit.

Most agent loops are made of a few hard steps (planning, writing the actual patch, the final answer) and many easy ones (classifying the request, summarising a file or tool output, extracting fields, checking formats, writing commit messages). If every step goes to GLM-5.3, you pay GLM-5.3 prices for the easy work too.

GLM-5.3-Flash is roughly a tenth of the price of GLM-5.3. If the endpoint is OpenAI-compatible and both models sit behind the same key, routing is one field:

``` python
from openai import OpenAI

client = OpenAI(base_url="https://api.iteracompute.com/v1", api_key="YOUR_KEY")

EASY = {"classify", "summarize_tool_output", "extract", "commit_message"}

def run(step: str, messages: list[dict]) -> str:
    model = "z-ai/glm-5.3-flash" if step in EASY else "z-ai/glm-5.3"
    r = client.chat.completions.create(model=model, messages=messages)
    return r.choices[0].message.content
```

The same pattern works with any OpenAI-compatible provider that serves both models. What changes is the bill.

| Model | Provider | Input | Cached input | Output | 
|---|---|---|---|---|
| GLM-5.3 | Z.ai (official) | 1.40 | 0.26 | 4.40 | 
| GLM-5.3 | IteraCompute | 0.82 | 0.20 | 2.88 | 
| GLM-5.3 | Sail Research (fp8, via OpenRouter) | 0.50 | 0.08 | 2.00 | 
| GLM-5.3-Flash | Z.ai (official) | 0.15 | 0.03 | 0.50 | 
| GLM-5.3-Flash | IteraCompute | 0.08 | 0.023 | 0.28 | 
| GLM-5.3-Flash | Near AI (fp8, via OpenRouter) | 0.08 | 0.012 | 0.50 | 
| DeepSeek V4.1 Flash | IteraCompute | 0.14 | 0.006 | 0.55 | 

Sail Research and Near AI are the cheapest standard (no promo) endpoints that declare fp8 for each model. One exception: at 0% cache hit, AkashML (fp8, 0.19 / 0.19 / 4.40) is a little cheaper than Sail for GLM-5.3, which would make that row $28.00 instead of $30.10 in the first table.

Workload assumption: 70% of tokens go to the cheap model and 30% to GLM-5.3, with the same 10:1 input-to-output ratio on both. Cache-hit rate is the share of input tokens billed at the cached price.

| Setup | 0% | 50% | 80% | 90% | 
|---|---|---|---|---|
| All GLM-5.3, Z.ai official | $184.00 | $127.00 | $92.80 | $81.40 | 
| All GLM-5.3, IteraCompute | $110.80 | $79.80 | $61.20 | $55.00 | 
| All GLM-5.3, Sail Research fp8 | $70.00 | $49.00 | $36.40 | $32.20 | 
| 70/30 mix, Z.ai official (one key) | $69.20 | $47.90 | $35.12 | $30.86 | 
| 70/30 mix, IteraCompute (one key) | $40.80 | $29.51 | $22.73 | $20.47 | 
| 70/30 mix with DeepSeek V4.1 Flash as the cheap model, IteraCompute | $46.89 | $32.90 | $24.51 | $21.71 | 
| 70/30 mix, Sail (GLM-5.3) + Near AI (Flash), two providers | $30.10 | $21.42 | $16.21 | $14.48 | 

Same workload, 50/50 split:

| Setup | 0% | 50% | 80% | 90% | 
|---|---|---|---|---|
| 50/50 mix, Z.ai official | $102.00 | $70.50 | $51.60 | $45.30 | 
| 50/50 mix, IteraCompute | $60.80 | $43.88 | $33.72 | $30.34 | 
| 50/50 mix, Sail + Near AI | $41.50 | $29.30 | $21.98 | $19.54 | 

If you want to check our prices for all models on one page, they're on the [IteraCompute pricing page](https://iteracompute.com/pricing/?utm_source=dev&utm_medium=social&utm_campaign=one_api_mix_202610&utm_content=20261027_dev_glm53mix_01). Model IDs are `z-ai/glm-5.3`, `z-ai/glm-5.3-flash` and `deepseek/deepseek-v4.1-flash` on an OpenAI-compatible endpoint.