GPT-OSS 120B API — pricing & specs

GPT-OSS 120B is a text model from OpenAI. On KeepRouter, GPT-OSS 120B costs $0.1500 per 1M input tokens and $0.6000 per 1M output tokens, billed pay-as-you-go with no monthly fee. Call it through a compatible KeepRouter endpoint supported by its active route, with the model id gpt-oss-120b.

MakerOpenAI
ModalityText
Input price$0.1500 per 1M tokens
Output price$0.6000 per 1M tokens
CapabilitiesChat completions, Streaming where supported, Tool calling where supported
EndpointPOST /v1/chat/completions or POST /v1/messages (compatible chat routes)
Model idgpt-oss-120b

How pricing works for GPT-OSS 120B

GPT-OSS 120B is billed per token — $0.1500 per 1M input tokens and $0.6000 per 1M output tokens. The published price is pay-as-you-go, with no monthly fee; actual request cost depends on measured token usage.

Calling GPT-OSS 120B on KeepRouter

Point a compatible client at the supported KeepRouter endpoint and set the model to gpt-oss-120b. KeepRouter preserves the client-facing request shape while handling upstream routing or translation. Use POST /v1/chat/completions or, on compatible chat routes, POST /v1/messages; streaming and tool support depend on the model's active route.

cURL

curl https://keeprouter.com/v1/chat/completions \
  -H "Authorization: Bearer $KEEPROUTER_KEY" -H "Content-Type: application/json" \
  -d '{"model":"gpt-oss-120b","messages":[{"role":"user","content":"Hello"}]}'

Python

import os
from openai import OpenAI
client = OpenAI(base_url="https://keeprouter.com/v1", api_key=os.environ["KEEPROUTER_KEY"])
r = client.chat.completions.create(model="gpt-oss-120b", messages=[{"role":"user","content":"Hello"}])

JavaScript

import OpenAI from "openai";
const client = new OpenAI({ baseURL: "https://keeprouter.com/v1", apiKey: process.env.KEEPROUTER_KEY });
const r = await client.chat.completions.create({ model: "gpt-oss-120b", messages: [{ role: "user", content: "Hello" }] });

Estimate API costs

At the current KeepRouter customer price, an example workload of 1,000 total input tokens, no cached input, and 500 output tokens per request costs approximately $0.000450 per request. At 100 requests per day, that is $1.35 over 30 days. This is a usage estimate, excluding processing fees, taxes, retries and application infrastructure. Actual usage, cache hits and supported generation durations need their own checks.

Adjust quantities in the API cost calculator.

How to evaluate GPT-OSS 120B

GPT-OSS 120B is listed on KeepRouter as text under the exact id gpt-oss-120b. Use /v1/chat/completions for the listed route; a maker's upstream features do not automatically apply to this gateway endpoint. No context limit is asserted here because the exact upstream limit has not been verified for this catalog entry.

First workload: Start with one representative text task, such as summarizing a document or drafting a structured answer. Compare answer quality, latency and billed input/output tokens.

Before production: For agent use, test tool calls and structured output on this exact model route before production; an OpenAI-compatible chat endpoint alone does not prove either feature.

Agent setup paths

OpenCode

OpenCode documents a custom OpenAI-compatible provider. Set baseURL to https://keeprouter.com/v1 and list gpt-oss-120b as a model; validate tool behavior on the exact route. Official setup.

{
  "$schema": "https://opencode.ai/config.json",
  "provider": {
    "keeprouter": {
      "npm": "@ai-sdk/openai-compatible",
      "name": "KeepRouter",
      "options": {
        "baseURL": "https://keeprouter.com/v1",
        "apiKey": "{env:KEEPROUTER_API_KEY}"
      },
      "models": {
        "gpt-oss-120b": {
          "name": "GPT-OSS 120B"
        }
      }
    }
  }
}

Continue

Continue documents provider: openai with a custom apiBase. Set apiBase to https://keeprouter.com/v1 and model to gpt-oss-120b; validate the selected feature and endpoint. Official setup.

name: KeepRouter
version: 0.0.1
schema: v1
models:
  - name: GPT-OSS 120B
    provider: openai
    model: gpt-oss-120b
    apiBase: https://keeprouter.com/v1
    apiKey: <YOUR_KEEPROUTER_API_KEY>

These are documented configuration paths; model-specific tool, streaming and multimodal behavior still needs a real request test.

Public model usage evidence

No public, exact-variant usage figure has been verified for this KeepRouter model id. Missing data is not zero usage; family-level or maker-wide traffic is not presented as this model's traffic.

Published examples and cases

No exact-model customer case has been verified for this entry. The workload above is an evaluation recipe, not a claim of a public deployment.

Source and verification boundary

Official OpenAI website. KeepRouter's live catalog is authoritative for the customer price and enabled endpoint shown here; the maker remains authoritative for upstream model capabilities and limits.

Pricing and implementation guides

Guides

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Catalog facts and prices last changed .

Page content reviewed .