What is Step 3.5 Flash?
Step 3.5 Flash is a language model in the o10 fulfillment catalog (slug: step-3.5-flash). Published input pricing starts at $0.090/1M tokens. Context window: 262K tokens.
Catalog snapshot 2026-06-27.
Step 3.5 Flash costs $0.090/1M input tokens and $0.300/1M output tokens as of 2026-06-27. Openrouter publishes this model with a 262K tokens context window. o10 lists Step 3.5 Flash on Together AI at routing band C2.
Last updated: 2026-06-27. Full catalog
Step 3.5 Flash — specs, hosts, and routing
AnswersSelf-contained
How much does Step 3.5 Flash cost per million tokens?
Step 3.5 Flash costs $0.090/1M input tokens and $0.300/1M output tokens in the gateway catalog snapshot (2026-06-27). Endpoint pricing may differ by fulfillment host.
Sourced from gateway catalog snapshot.
Where can you run Step 3.5 Flash?
Step 3.5 Flash is configured on Together AI. Each host maps to an upstream model ID listed in the fulfillment routes table. This model is routable through o10 eval-gated routing.
What is Step 3.5 Flash's context window?
Step 3.5 Flash supports a 262K tokens context window in the gateway catalog snapshot. Context limits may vary by fulfillment host endpoint.
What o10 routing band is Step 3.5 Flash?
Step 3.5 Flash is classified at o10 routing band C2. Bands group models by cost tier and eval profile: C0 (economy), C1 (standard), C2 (capable), C3/C4 (frontier). Production routing is enabled for this slug.
Who makes Step 3.5 Flash?
Step 3.5 Flash is attributed to source provider openrouter in the o10 catalog. Fulfillment hosts (Together AI) supply API access; list pricing may differ by venue.
01Deep dive
Specifications
Step 3.5 Flash in the o10 unified catalog.
| Field | Value |
|---|---|
| o10 slug | `step-3.5-flash` |
| Type | text |
| Band | C2 |
| Routable | Yes |
| Source provider | openrouter |
| Primary host | Together AI |
| Gateway ID | `stepfun/step-3.5-flash` |
| Context window | 262,114 tokens |
| Released | 2026-01-29 |
02Deep dive
Token pricing
Gateway snapshot pricing for Step 3.5 Flash.
| Unit | Price |
|---|---|
| Input | $0.09/1M tokens |
| Output | $0.3/1M tokens |
03Deep dive
Fulfillment hosts
Upstream venues configured for Step 3.5 Flash.
| Host | Upstream model ID |
|---|---|
| stepfun | together_ai/step-3.5-flash |
04Deep dive
Gateway provider endpoints
Endpoint-level pricing and latency from the gateway catalog.
| Provider | Input ($/1M) | Latency p50 | Uptime 1d |
|---|---|---|---|
| deepinfra | $0.09 | 193ms | 10000.0% |
05Deep dive
Routing with o10
Eval-gated model selection for this slug.
o10 slug: step-3.5-flash. Band: C2. Routable: yes.
See [/models/routing](/models/routing) for smart aliases (o10/auto, o10/economy) and [/kyi](/kyi) for governance.
SourceMethodology
Fulfillment catalog 2026-06-27. Gateway pricing joined where slug match exists.
FAQFrequently asked questions
Common questions
How much does Step 3.5 Flash cost?
Step 3.5 Flash costs $0.090/1M input tokens and $0.300/1M output tokens in the gateway snapshot (2026-06-27). Verify against your provider's published pricing.
What is Step 3.5 Flash's context window?
Step 3.5 Flash supports 262K tokens in the gateway catalog snapshot. Host-specific endpoints may differ.
Which hosts serve Step 3.5 Flash?
Step 3.5 Flash (step-3.5-flash) is configured on: Together AI. Upstream model IDs are listed in the fulfillment routes section.
Is Step 3.5 Flash routable through o10?
Yes. Step 3.5 Flash is routable at band C2. Send model: "step-3.5-flash" or use an o10 smart routing alias.
How do I call Step 3.5 Flash via o10?
Use o10 slug "step-3.5-flash" or gateway ID "stepfun/step-3.5-flash" depending on your integration. Gateway-compatible endpoints accept OpenAI-style /v1 requests.
How does o10 route this model?
o10 routes Step 3.5 Flash only when per-use-case evals clear at your quality floor. Band C2 indicates cost tier. See /kyi for governance and /models/routing for smart aliases.