Beam 1.0 501B A23B

Beam 1.0 is Reflection's open-weight reasoning model for coding and long-horizon agentic workflows. It uses a sparse mixture-of-experts architecture with 501B total and 23B active parameters per token, and a 1M-token context window. Beam targets software engineering, multi-step tool use, and mathematical and scientific reasoning, with an emphasis on token efficiency. It takes text input and produces text output, supports configurable reasoning effort, function calling and structured outputs, and is released under Apache 2.0.

ChatReflection1M tokens$0.327 / $1.0901 · 1M

reflection/beam-1.0-501b-a23b

Context
1M tokens
Completion cap
943,718
Tools
Yes
JSON
Yes
Released
2026-10-16

Call it from Geek Hub

Same OpenAI SDK. Change the base URL and the model id.

curl https://api.geekhub.mx/v1/chat/completions \
  -H "Authorization: Bearer $GEEKHUB_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "reflection/beam-1.0-501b-a23b",
    "messages": [{"role": "user", "content": "Hola"}]
  }'
Get an API key

Frequently asked questions

What is Beam 1.0 501B A23B?
Beam 1.0 is Reflection's open-weight reasoning model for coding and long-horizon agentic workflows. It uses a sparse mixture-of-experts architecture with 501B total and 23B active parameters per token, and a 1M-token context window. Beam targets software engineering, multi-step tool use, and mathematical and scientific reasoning, with an emphasis on token efficiency. It takes text input and produces text output, supports configurable reasoning effort, function calling and structured outputs, and is released under Apache 2.0. Beam 1.0 501B A23B runs on the Geek Hub API (OpenAI-compatible). Model id: reflection/beam-1.0-501b-a23b.
Is Beam 1.0 501B A23B free?
No. Input is $0.327 per 1M tokens and output is $1.0901 per 1M tokens on Geek Hub (markup included).
What is the context length of Beam 1.0 501B A23B?
Beam 1.0 501B A23B has a 1M tokens context window. It supports up to 943,718 completion tokens.
Does Beam 1.0 501B A23B support tool calling and structured outputs?
Beam 1.0 501B A23B accepts tools and tool_choice for function calling. It also supports structured outputs via a JSON schema in response_format.
When was Beam 1.0 501B A23B released?
Beam 1.0 501B A23B was released on 2026-10-16.