GPT-5.4 Nano
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:$0.13/M. Automatic prefix caching once a prompt passes the minimum length, with no code changes; cached reads are discounted (up to 90% on current models) and there is no write fee.
Use GPT-5.4 Nano 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="gpt-5.4-nano",
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: "gpt-5.4-nano",
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": "gpt-5.4-nano",
"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: "gpt-5.4-nano",
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("gpt-5.4-nano")
.addUserMessage("Summarize this diff")
.reasoningEffort(ReasoningEffort.MEDIUM)
.build());
System.out.println(resp.choices().get(0).message().content().orElse(""));About GPT-5.4 Nano
GPT-5.4 Nano is the cheapest GPT-5.4-class model, built for simple, high-volume tasks such as classification, data extraction, ranking, and lightweight subagent steps.
- It keeps the family's 400K-token context window and 128K max output while trading peak reasoning depth for speed and cost efficiency, and supports streaming, function calling, and structured outputs with an August 2025 knowledge cutoff.
- When budget per call is the binding constraint, it is the family's high-volume option.
- Synthorai serves GPT-5.4 Nano over the standard OpenAI-compatible chat interface.
Specs & limits
| Max output (vendor spec) | 128,000 |
| Modalities | text + image → text |
| Features | tools · parallel_tool_calls · structured_output · streaming · vision · batch · reasoning · realtime · caching |
| Notable | Cheapest GPT-5.4-class model, targeted at classification/extraction/ranking/subagents; computer use and tool search not supported. |
| Prompt caching | automatic · min 1,024-token prefix · TTL 5–10m, up to 1h |
FAQ
Is the GPT-5.4 Nano API free to try?
Yes: new accounts get 10 trial calls and up to $1 in free credit, no card required. At $0.2/M input tokens, that credit alone covers roughly 625 requests of ~8K tokens against GPT-5.4 Nano.
What is GPT-5.4 Nano best at?
Cheapest model of its class, plus trades reasoning depth for speed and cost and keeps 400K context and 128K output. See the About section for the full picture from the vendor's own release notes.
How much does GPT-5.4 Nano cost?
GPT-5.4 Nano costs $0.2 per million input tokens and $1.25 per million output tokens on Synthorai. That is the provider's list price, with no platform markup. Cached input tokens bill at $0.1/M.
Does GPT-5.4 Nano support prompt caching?
Yes, automatically: OpenAI-served prompts cache with no code changes. Cached input tokens bill at $0.1/M vs $0.2/M uncached; prompts need a 1,024-token stable prefix to cache (TTL 5–10m, up to 1h). Prompt caching guide →
How do I get access to GPT-5.4 Nano?
Point your existing OpenAI SDK at base_url="https://synthorai.io/v1", set model="gpt-5.4-nano", and you're done. One API key covers every model on the gateway.
What is GPT-5.4 Nano's knowledge cutoff?
GPT-5.4 Nano's knowledge cutoff is 2025-08, per the vendor's official documentation (as of 2026-07-09).