Qwen3.5 Plus
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:$0.2005/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 Plus 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-plus",
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-plus",
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-plus",
"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-plus",
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-plus")
.addUserMessage("Summarize this diff")
.reasoningEffort(ReasoningEffort.MEDIUM)
.build());
System.out.println(resp.choices().get(0).message().content().orElse(""));About Qwen3.5 Plus
Qwen3.5 Plus is the flagship hosted tier of the Qwen3.5 generation, the Qwen team's step "Towards Native Multimodal Agents." Built on the Qwen3-Next architecture pairing gated linear attention with sparse Mixture-of-Experts, the generation uses early-fusion multimodal training and emphasizes agentic capability across reasoning, coding, and tool use, with adaptive tool-calling modes.
- The hosted Plus tier provides a 1M-token context window by default, suited to large-document and long-horizon agent workloads.
- Synthorai routes Qwen3.5 Plus traffic through its OpenAI-compatible API.
Specs & limits
| Max output (vendor spec) | 65,536 |
| Modalities | text + image + video → text |
| Parameters | 397B total · 17B active (MoE) |
| Features | tools · structured_output · streaming · vision · batch · reasoning · parallel_tool_calls · caching |
| Notable | Cloud-hosted counterpart of Qwen3.5-397B-A17B (native VLM, Gated-Delta linear attention + sparse MoE); 1M-token context by default, built-in tools, 201 languages; hybrid thinking on by default. |
| Prompt caching | automatic + explicit · TTL explicit: 5m, reset on hit |
FAQ
Is the Qwen3.5 Plus API free to try?
Yes: new accounts get 10 trial calls and up to $1 in free credit, no card required. At $0.4/M input tokens, that credit alone covers roughly 312 requests of ~8K tokens against Qwen3.5 Plus.
What is Qwen3.5 Plus best at?
Early-fusion multimodal training, plus adaptive tool-calling modes and 1M-token context window by default. See the About section for the full picture from the vendor's own release notes.
How much does Qwen3.5 Plus cost?
Qwen3.5 Plus costs $0.4 per million input tokens and $2.4 per million output tokens on Synthorai. That is the provider's list price, with no platform markup. Cached input tokens bill at $0.115/M.
Does Qwen3.5 Plus support prompt caching?
Yes: automatic caching is on by default, with an explicit mode for guaranteed savings. Cached input tokens bill at $0.115/M vs $0.4/M uncached (TTL explicit: 5m, reset on hit). Prompt caching guide →
How do I get access to Qwen3.5 Plus?
Point your existing OpenAI SDK at base_url="https://synthorai.io/v1", set model="qwen3.5-plus", and you're done. One API key covers every model on the gateway.