OpenAI compatible API · Attested · Public status

JetBrains Mellum2 12B A2.5B vs OpenAI: gpt-oss-120b

JetBrains Mellum2 12B A2.5B vs gpt-oss-120b: compare current API pricing, context, provider routes, privacy, p50 latency, and OpenAI-compatible access.

Verify gateway

Onebase URL to migrate

100sof models and routes

0prompt or output logs. Always.

Compare routesProviders, price, context, and policy posture in one view.

Use auto when uptime mattersKeep a primary model and let fallback handle provider failures.

Same API shapeUse the OpenAI client and set the model you want.

Practical read

Monthly evidence

JetBrains Mellum2 12B A2.5B has the lower cheapest prompt+completion route on TrustedRouter. OpenAI: gpt-oss-120b has more provider fallback routes, while JetBrains Mellum2 12B A2.5B has the larger context window. Current TrustedRouter probes show OpenAI: gpt-oss-120b with the lower p50 TTFT.

$0.15825/1MJetBrains Mellum2 12B A2.5B cheapest route

$0.211/1MOpenAI: gpt-oss-120b cheapest route

1495 msJetBrains Mellum2 12B A2.5B fastest measured p50 TTFT via wandb

596 msOpenAI: gpt-oss-120b fastest measured p50 TTFT via cerebras

Prices and live route measurements can change. Use the monthly reports when you need a stable evidence window, then run a small task-specific eval before choosing a production default.

JetBrains Mellum2 12B A2.5BOpenAI: gpt-oss-120b

Model idjetbrains/mellum2-12b-a2.5b-instructopenai/gpt-oss-120b

Publisher Weights & Biases OpenAI

AI IQ — IQ 105#70

Context131,072 tokens131,072 tokens

Credits provider routes119

Cheapest route$0.15825/1M$0.211/1M

Cached inputNot published$0.015825/1M to $0.1055/1M

Privacy postureprovider posture varieshas provider E2EE route

Fastest measured p50 TTFT1495 ms via wandb596 ms via cerebras

Highest measured throughputnot enough datanot enough data

Recent route uptime range100.00%0.00% to 100.00%

Modes chat chat

JetBrains Mellum2 12B A2.5B routes

Overview1 Credits routes

OpenAI: gpt-oss-120b routes

Overview19 Credits routes
PricingInput, cached input, and output rates
ProvidersAll serving providers

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Production choice

Pick a default model. Keep fallback enabled.

TrustedRouter is useful when you know the model you want, but still need provider rollover, budget limits, usage records, and a prompt path you can verify.

OpenAI clientPython

client = OpenAI(
    base_url="https://api.trustedrouter.com/v1",
    api_key="sk-tr-v1-..."
)

response = client.chat.completions.create(
    model="jetbrains/mellum2-12b-a2.5b-instruct",
    messages=messages,
)

Questions

Which should I use, JetBrains Mellum2 12B A2.5B or OpenAI: gpt-oss-120b?

Is JetBrains Mellum2 12B A2.5B or OpenAI: gpt-oss-120b cheaper?

The current cheapest TrustedRouter route is $0.15825/1M for JetBrains Mellum2 12B A2.5B and $0.211/1M for OpenAI: gpt-oss-120b. The comparison uses current catalog prices and updates as provider pricing changes.

Is JetBrains Mellum2 12B A2.5B or OpenAI: gpt-oss-120b faster?

Current measured p50 time to first token is 1495 ms for JetBrains Mellum2 12B A2.5B and 596 ms for OpenAI: gpt-oss-120b. These are routed probe measurements, not vendor-advertised speeds, and update as new samples arrive.

Can I test JetBrains Mellum2 12B A2.5B and OpenAI: gpt-oss-120b with the same API?

Yes. Use the same OpenAI-compatible TrustedRouter base URL and API key, then change only the model id between jetbrains/mellum2-12b-a2.5b-instruct and openai/gpt-oss-120b. This makes side-by-side evals possible without maintaining two provider integrations.