Seed 1.8 API

bytedance/seed-1-8
ByteDance Seed 1.
Context
256K tokens
Input
$0.325 / 1M tokens
Output
$2.6 / 1M tokens
Released
Jan 12, 2026

How to use Seed 1.8 API

Install any OpenAI-compatible SDK, point it at api.aimlapi.com/v1, and set the model to bytedance/seed-1-8.
import requests

r = requests.post(
    "https://api.aimlapi.com/v1/chat/completions",
    headers={"Authorization": "Bearer " + AIMLAPI_KEY},
    json={
      "model": "bytedance/seed-1-8",
      "messages": [
        {
          "role": "user",
          "content": "Hello!"
        }
      ]
    },
)
print(r.json())
const r = await fetch("https://api.aimlapi.com/v1/chat/completions", {
  method: "POST",
  headers: {
    Authorization: `Bearer ${process.env.AIMLAPI_KEY}`,
    "Content-Type": "application/json",
  },
  body: JSON.stringify({
    "model": "bytedance/seed-1-8",
    "messages": [
      {
        "role": "user",
        "content": "Hello!"
      }
    ]
  }),
});
console.log(await r.json());
curl -X POST https://api.aimlapi.com/v1/chat/completions \
  -H "Authorization: Bearer $AIMLAPI_KEY" \
  -H "Content-Type: application/json" \
  -d '{"model":"bytedance/seed-1-8","messages":[{"role":"user","content":"Hello!"}]}'

OpenAI-compatible — swap the base URL and it works with your existing SDK.

Seed 1.8 API Pricing

TypePrice
Input
$0.325 / 1M tokens
Output
$2.6 / 1M tokens

Seed 1.8 Benchmarks

BenchmarkScoreWhat it measuresSourceRetrieved
MMLU
92.3
Multi-discipline knowledge across 57 school and professional subjectsSourceSeptember 22, 2026
GPQA Diamond
83.8
Google-proof graduate science questions (hardest subset)SourceSeptember 22, 2026
SWE-bench Verified
72.9
Resolving verified real GitHub issuesSourceSeptember 22, 2026
AIME 2025
94.6
Competition mathematics (AIME), 2025SourceSeptember 22, 2026
LiveCodeBench
79.5
Contamination-free competitive programming problemsSourceSeptember 22, 2026

Frequently asked questions

Seed 1.8 has a 256,000 tokens context window and can return up to 224,000 tokens.

Seed 1.8 takes image, text as input and returns text.

Use bytedance/seed-1-8 as the model id. Requests go to https://api.aimlapi.com/v1/chat/completions.

Seed 1.8 is priced at input $0.325 / 1M tokens, output $2.6 / 1M tokens.

Yes, Seed 1.8 can stream responses as they are generated.

Yes, Seed 1.8 accepts image input alongside text.

Seed 1.8 was built by ByteDance.

It supports function calling, streaming, structured outputs, parallel tool calls, and vision input alongside text.

Start building with Seed 1.8

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