Models / StepFun
Step 3.5 Flash API pricing
$0.40 in, $1.20 out per million tokens.
Price · per million tokens, USD
Get a key| Tokens | StepFun list price | UplinkSwitch | Saving |
|---|---|---|---|
| Input | — | $0.40 | — |
| Cached input | Billed at the input rate. | ||
| Output | — | $1.20 | — |
Step 3.5 Flash: what it is · from StepFun’s own model card, read 2026-10-20
StepFun’s most capable open model, a mixture of experts for reasoning and agent work. StepFun reports 100 to 300 tokens a second in typical use from three-way multi-token prediction. It is served as step-3.5-flash at $0.40 input and $1.20 output per million tokens, on the same key as every other model in the catalog.
| Step 3.5 Flash | |
|---|---|
| Developer | StepFun |
| Parameters | 196B total, 11B active per token |
| Context | 256K tokens |
| License | Apache-2.0 |
| Published | 2026-02-01 |
| Downloads, 30 days to 2026-10-20 | 264,011 |
| Source | stepfun-ai/Step-3.5-Flash |
From stepfun-ai/Step-3.5-Flash, read 2026-10-20.
curl https://api.uplinkswitch.com/v1/chat/completions \
-H "authorization: Bearer sk-uplink-live-..." \
-H "content-type: application/json" \
-d '{"model":"step-3.5-flash","max_tokens":1024,"messages":[{"role":"user","content":"Hello"}]}'Step 3.5 Flash next to StepFun’s other models · per million tokens, live
| Model | Here, in / out | 1,000 chat turns |
|---|---|---|
| Step 3.5 Flash | $0.40 / $1.20 | $1.40 |
A chat turn is 2,000 input and 500 output tokens. Live from the catalog, ordered by the cost of 1,000 turns.
Worked for Step 3.5 Flash: 1,000 turns are 2,000,000 input tokens and 500,000 output tokens. At $0.40 input and $1.20 output per million tokens, that is $0.80 + $0.60 = $1.40, paid from prepaid credit with no subscription.
Step 3.5 Flash API key · base URL and setup
- Create a key in the console at uplinkswitch.ai/console. Credit is prepaid from $10 with no subscription, and the key works at once.
- Point your SDK or tool at https://api.uplinkswitch.com/v1, for example with OPENAI_BASE_URL, and send the key as the bearer token.
- Send step-3.5-flash as the model. The same key calls every other model in the catalog.
from openai import OpenAI
client = OpenAI(
base_url="https://api.uplinkswitch.com/v1",
api_key="sk-uplink-live-...",
)
completion = client.chat.completions.create(
model="step-3.5-flash",
messages=[{"role": "user", "content": "Summarize this in one line."}],
)
print(completion.choices[0].message.content)import OpenAI from 'openai';
const client = new OpenAI({
baseURL: 'https://api.uplinkswitch.com/v1',
apiKey: 'sk-uplink-live-...',
});
const completion = await client.chat.completions.create({
model: 'step-3.5-flash',
messages: [{ role: 'user', content: 'Summarize this in one line.' }],
});
console.log(completion.choices[0].message.content);curl https://api.uplinkswitch.com/v1/chat/completions \
-H "authorization: Bearer sk-uplink-live-..." \
-H "content-type: application/json" \
-d '{"model":"step-3.5-flash","messages":[{"role":"user","content":"Hello"}]}'What would it cost? · paste a prompt, priced before you send it
Input is counted at about 4 characters per token.
Cheapest first. A real request is billed on the provider's own token count. Same estimate as JSON: POST https://api.uplinkswitch.com/v1/estimate, no key needed.