Qwen3.5 Flash
Provider list prices: no platform markup, pay-as-you-go. These are official list prices. Logged-in customers may see effective prices including workspace discounts on /console/pricing. Effective input at a 70% cache-hit rate:$0.0503/M. Implicit context cache is automatic; an explicit cache_control mode offers deeper discounts (1,024-token minimum blocks, 5-minute TTL that resets on hit). Per-model cached-read prices are in the pricing table.
Use Qwen3.5 Flash in 30 seconds
OpenAI-compatible: swap the base_url, keep your SDK. POST /v1/chat/completions
from openai import OpenAI
client = OpenAI(
base_url="https://synthorai.io/v1",
api_key="sk-syn-...",
)
resp = client.chat.completions.create(
model="qwen3.5-flash",
messages=[{"role": "user", "content": "Summarize this diff"}],
reasoning_effort="medium",
)
print(resp.choices[0].message.content)import OpenAI from "openai";
const client = new OpenAI({
baseURL: "https://synthorai.io/v1",
apiKey: "sk-syn-...",
});
const resp = await client.chat.completions.create({
model: "qwen3.5-flash",
messages: [{ role: "user", content: "Summarize this diff" }],
reasoning_effort: "medium",
});
console.log(resp.choices[0].message.content);curl https://synthorai.io/v1/chat/completions \
-H "Authorization: Bearer sk-syn-..." \
-H "Content-Type: application/json" \
-d '{
"model": "qwen3.5-flash",
"messages": [{"role": "user", "content": "Hello"}],
"reasoning_effort": "medium"
}'package main
import (
"context"
"fmt"
"github.com/openai/openai-go/v3"
"github.com/openai/openai-go/v3/option"
)
func main() {
client := openai.NewClient(
option.WithBaseURL("https://synthorai.io/v1"),
option.WithAPIKey("sk-syn-..."),
)
resp, _ := client.Chat.Completions.New(context.TODO(), openai.ChatCompletionNewParams{
Model: "qwen3.5-flash",
Messages: []openai.ChatCompletionMessageParamUnion{
openai.UserMessage("Summarize this diff"),
},
ReasoningEffort: openai.ReasoningEffortMedium,
})
fmt.Println(resp.Choices[0].Message.Content)
}import com.openai.client.OpenAIClient;
import com.openai.client.okhttp.OpenAIOkHttpClient;
import com.openai.models.chat.completions.*;
import com.openai.models.ReasoningEffort;
OpenAIClient client = OpenAIOkHttpClient.builder()
.baseUrl("https://synthorai.io/v1")
.apiKey("sk-syn-...")
.build();
ChatCompletion resp = client.chat().completions().create(
ChatCompletionCreateParams.builder()
.model("qwen3.5-flash")
.addUserMessage("Summarize this diff")
.reasoningEffort(ReasoningEffort.MEDIUM)
.build());
System.out.println(resp.choices().get(0).message().content().orElse(""));About Qwen3.5 Flash
Qwen3.5 Flash is the speed- and cost-optimized hosted tier of the Qwen3.5 generation, which the Qwen team introduced under the banner "Towards Native Multimodal Agents." The generation is built on the Qwen3-Next architecture combining gated linear attention with sparse Mixture-of-Experts for high-throughput inference, and is trained natively for agentic work: planning, tool calling, and multi-step execution.
- The hosted Flash tier offers a 1M-token context by default with official built-in tools.
- Synthorai puts it behind the standard OpenAI-compatible endpoint for drop-in use.
Specs & limits
| Modalities | text + image + video → text |
| Parameters | 35B total · 3B active (MoE) |
| Features | tools · structured_output · streaming · vision · batch · reasoning · parallel_tool_calls · caching |
| Notable | Native vision-language flash model (text/image/video input); hybrid thinking on by default; overall quality officially positioned close to qwen3.5-plus. |
| Prompt caching | automatic + explicit · TTL explicit: 5m, reset on hit |
FAQ
Is the Qwen3.5 Flash API free to try?
Yes: new accounts get 10 trial calls and up to $1 in free credit, no card required. At $0.1/M input tokens, that credit alone covers roughly 1,250 requests of ~8K tokens against Qwen3.5 Flash.
What is Qwen3.5 Flash best at?
Gated linear attention with sparse MoE, plus 1M-token context by default and trained natively for agentic work. See the About section for the full picture from the vendor's own release notes.
How much does Qwen3.5 Flash cost?
Qwen3.5 Flash costs $0.1 per million input tokens and $0.4 per million output tokens on Synthorai. That is the provider's list price, with no platform markup. Cached input tokens bill at $0.029/M.
Does Qwen3.5 Flash support prompt caching?
Yes: automatic caching is on by default, with an explicit mode for guaranteed savings. Cached input tokens bill at $0.029/M vs $0.1/M uncached (TTL explicit: 5m, reset on hit). Prompt caching guide →
How do I get access to Qwen3.5 Flash?
Point your existing OpenAI SDK at base_url="https://synthorai.io/v1", set model="qwen3.5-flash", and you're done. One API key covers every model on the gateway.