StepFun: Step 5 Preview

stepfun/step-5-preview

Last Observed: 2026-10-15 06:04:16.393291 UTC

Step 5 Preview is StepFun's flagship model for agentic work, built on a sparse Mixture-of-Experts architecture (27B active / 600B total parameters). It performs strongly in software engineering and professional...

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Architecture And Modalities · 2

Architecture · Modality API Details /architecture/modality text+image+video->text	text+image+video->text
Architecture · Tokenizer API Details /architecture/tokenizer Other	Other

Catalog Identity And Metadata · 14

Context Tokens API Details /context_length 1048576	1,048,576
Created API Details /created 1791462849	2026-10-08 12:34:09 UTC
Description API Details /description Step 5 Preview is StepFun's flagship model for agentic work, built on a sparse Mixture-of-Experts architecture (27B active / 600B total parameters). It performs strongly in software engineering and professional...	Step 5 Preview is StepFun's flagship model for agentic work, built on a sparse Mixture-of-Experts architecture (27B active / 600B total parameters). It performs strongly in software engineering and professional...
Expiration Date API Details /expiration_date Explicit Null	Explicit Null
Id API Details /id stepfun/step-5-preview	stepfun/step-5-preview
Is Free API Details /isFree False	False
May Train On Your Prompts API Details /mayTrainOnYourPrompts False	False
Name API Details /name StepFun: Step 5 Preview	StepFun: Step 5 Preview
Opencode · Variants · High · Reasoning · Effort API Details /opencode/variants/high/reasoning/effort high	high
Opencode · Variants · High · Reasoning · Enabled API Details /opencode/variants/high/reasoning/enabled True	True
Opencode · Variants · Low · Reasoning · Effort API Details /opencode/variants/low/reasoning/effort low	low
Opencode · Variants · Low · Reasoning · Enabled API Details /opencode/variants/low/reasoning/enabled True	True
Opencode · Variants · Medium · Reasoning · Effort API Details /opencode/variants/medium/reasoning/effort medium	medium
Opencode · Variants · Medium · Reasoning · Enabled API Details /opencode/variants/medium/reasoning/enabled True	True

Request Limits · 1

Per Request Limits API Details /per_request_limits Explicit Null	Explicit Null

Pricing · 4

Output Price · USD/Token API Details /pricing/completion 0.0000027	0.0000027
Pricing · Discount API Details /pricing/discount 0	0
Pricing · Input Cache Read API Details /pricing/input_cache_read 0.00000005	0.00000005
Input Price · USD/Token API Details /pricing/prompt 0.000001	0.000001

Provider Limits · 3

Top Provider · Context Length API Details /top_provider/context_length 1000000	1,000,000
Top Provider · Is Moderated API Details /top_provider/is_moderated False	False
Top Provider · Max Completion Tokens API Details /top_provider/max_completion_tokens 64000	64,000

API Structure And Container Types

Architecture API Details /architecture Object · See Fields	Object · See Fields
Architecture · Input Modalities API Details /architecture/input_modalities Array · See Items	Array · See Items
Architecture · Output Modalities API Details /architecture/output_modalities Array · See Items	Array · See Items
Opencode API Details /opencode Object · See Fields	Object · See Fields
Opencode · Variants API Details /opencode/variants Object · See Fields	Object · See Fields
Opencode · Variants · High API Details /opencode/variants/high Object · See Fields	Object · See Fields
Opencode · Variants · High · Reasoning API Details /opencode/variants/high/reasoning Object · See Fields	Object · See Fields
Opencode · Variants · Low API Details /opencode/variants/low Object · See Fields	Object · See Fields
Opencode · Variants · Low · Reasoning API Details /opencode/variants/low/reasoning Object · See Fields	Object · See Fields
Opencode · Variants · Medium API Details /opencode/variants/medium Object · See Fields	Object · See Fields
Opencode · Variants · Medium · Reasoning API Details /opencode/variants/medium/reasoning Object · See Fields	Object · See Fields
Pricing API Details /pricing Object · See Fields	Object · See Fields
Supported Parameters API Details /supported_parameters Array · See Items	Array · See Items
Top Provider API Details /top_provider Object · See Fields	Object · See Fields

Architecture · Input Modalities

3 items · source order preserved

text
image
video

API Details

Item	/architecture/input_modalities/*
1	text
2	image
3	video

Architecture · Output Modalities

1 items · source order preserved

text

API Details

Item	/architecture/output_modalities/*
1	text

Supported Parameters

20 items · source order preserved

frequency_penalty
include_reasoning
logit_bias
logprobs
max_tokens
min_p
presence_penalty
reasoning
reasoning_effort
repetition_penalty
response_format
seed
stop
structured_outputs
temperature
tool_choice
tools
top_k
top_logprobs
top_p

API Details

Item	/supported_parameters/*
1	frequency_penalty
2	include_reasoning
3	logit_bias
4	logprobs
5	max_tokens
6	min_p
7	presence_penalty
8	reasoning
9	reasoning_effort
10	repetition_penalty
11	response_format
12	seed
13	stop
14	structured_outputs
15	temperature
16	tool_choice
17	tools
18	top_k
19	top_logprobs
20	top_p

Recorded Value History

Historical API Field

Input Price · USD/Token

2 of 2 records plotted · 0 excluded for missing or invalid coordinates.

Up to 100 recorded versions, spaced by observation order rather than elapsed time. Array fields use the minimum numeric item in each version. Missing values are omitted. Select a point to open its archived snapshot; comparison actions use the current listing. History begins at the first recorded baseline.

Axis Scale

Select a point to open its listing or add it to compare.

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