What is the cost of Upstage Solar Pro 3 in Atlas?

Upstage Solar Pro 3 is priced at $0.25 per Mtok for both input and output, offering symmetric pricing that makes verbose agent turns more economical within Atlas.

What is the context window for Upstage Solar Pro 3?

Upstage Solar Pro 3 provides a substantial 131,072 token context window, doubling the capacity of Solar Pro 2 while maintaining the same price point.

Can Upstage Solar handle large file rewrites in Atlas?

Upstage Solar Pro models have a maximum output of 8,192 tokens, and solar-mini has 4,096 tokens. This means large single-shot file rewrites will not fit, so Atlas's unified-diff review is crucial for managing changes.

Is solar-mini a good choice for a `small_model` in Atlas?

Yes, solar-mini is an excellent choice for a `small_model` in Atlas, offering a 32,768 token window at a competitive $0.15/$0.15 per Mtok, and it is tuned for Korean and document extraction.

How does Upstage Solar's pricing compare to other models for Atlas?

Upstage Solar's symmetric pricing, where input and output cost the same ($0.25/$0.25 per Mtok for Pro 3), is rare. This contrasts with many other providers where output tokens can be 4x to 10x more expensive.

What are the steps to set up Upstage Solar in Atlas?

To set up Upstage Solar, export your `UPSTAGE_API_KEY`, run `atlas models upstage` to confirm resolution, and then pin `"model": "upstage/solar-pro3"` and `"small_model": "upstage/solar-mini"` in your `atlas.json` configuration.

Is Upstage Solar benchmarked against frontier models like GPT-5?

Upstage Solar has not been benchmarked head-to-head with frontier-tier models like Claude or GPT-5 on large-repo agentic coding tasks. It offers three models but does not include a frontier tier.

Atlas with Upstage Solar in 2026

Upstage Solar models offer a compelling choice for Atlas users in 2026, particularly for tasks requiring extensive reasoning without incurring high output costs. Solar Pro 3, priced at $0.25/$0.25 per Mtok, provides a substantial 131,072 token context window, making it ideal for deep code analysis and iterative development within Atlas.

Why choose Upstage Solar for Atlas in 2026?

For developers using Atlas in 2026, Upstage Solar Pro 3 stands out with its unique symmetric pricing of $0.25 per Mtok for both input and output. This model's 131,072 token context window allows for extensive code analysis without the typical 4x to 10x premium on output tokens, making reasoning-heavy tasks more budget-friendly.

Upstage Solar Pro 3's symmetric pricing structure is a significant advantage for Atlas users. Unlike many models where output tokens can cost 4x to 10x more than input, Solar Pro 3 maintains a flat $0.25 per Mtok for both directions. This changes the economic calculus for agentic workflows, allowing Atlas to perform verbose, reasoning-heavy turns without disproportionately increasing costs. The generous 131,072 token context window of Solar Pro 3 further enhances Atlas's capabilities, enabling deep code understanding through Axis, the hybrid semantic and keyword code search, and comprehensive planning in the read-only plan agent. This combination supports more thorough code indexing by AST declarations using tree-sitter and detailed unified diff reviews, making iterative development cycles more efficient.

What are the context window and pricing for Upstage Solar models?

Upstage Solar offers three distinct models for Atlas users in 2026, each with specific context windows and pricing. Solar Pro 3 leads with a 131,072 token context window at $0.25/$0.25 per Mtok, while solar-mini provides a 32,768 token window for just $0.15/$0.15 per Mtok, offering a cost-effective option.

Upstage provides three models within its Solar API for Atlas integration. Solar Pro 3 offers the largest context window at 131,072 tokens, priced symmetrically at $0.25 per Mtok for both input and output. This model effectively doubles the context of Solar Pro 2, which has a 65,536 token window, while maintaining the exact same $0.25/$0.25 per Mtok pricing. For more cost-sensitive tasks or as a dedicated `small_model` within Atlas, solar-mini is available with a 32,768 token context window at an even lower symmetric price of $0.15 per Mtok for both input and output. Solar-mini is also specifically tuned by the Korean lab for Korean language processing and document extraction tasks, adding specialized utility.

What are the tradeoffs when using Upstage Solar with Atlas?

While Upstage Solar models offer significant advantages for Atlas in 2026, developers should be aware of certain tradeoffs. The maximum output token limit is 8,192 for Solar Pro models and 4,096 for solar-mini, meaning large single-shot file rewrites will not fit within a single turn.

A primary tradeoff when using Upstage Solar with Atlas is the maximum output token limit. Solar Pro models are capped at 8,192 tokens for output, and solar-mini is limited to 4,096 tokens. This constraint means that Atlas cannot perform very large, single-shot file rewrites in a single agent turn. Developers will need to keep changes scoped and rely on Atlas's robust unified-diff review process to manage and approve edits incrementally. Additionally, Upstage Solar offers three models in total, but there is no frontier tier available. The models have not been benchmarked head-to-head with leading models like Claude or GPT-5 on complex, large-repository agentic coding tasks, which might be a consideration for developers requiring state-of-the-art performance in those specific scenarios.

When should I consider a different model for Atlas?

Despite its strengths, Upstage Solar may not be the optimal choice for every Atlas workflow in 2026. If your primary need involves single-shot file rewrites exceeding 8,192 tokens, or if you require a model benchmarked against frontier-tier options like Claude or GPT-5 for large-repo agentic coding, you might explore other providers.

Developers should consider alternative models for Atlas if their workflow frequently demands single-shot file rewrites that exceed the 8,192 token output limit of Solar Pro models or the 4,096 token limit of solar-mini. While Atlas's unified-diff review system helps manage incremental changes, tasks requiring massive, atomic file transformations might be better suited for models with higher output caps. Furthermore, if your projects involve large-repository agentic coding where head-to-head benchmarking against frontier-tier models like Claude or GPT-5 is a critical performance indicator, Upstage Solar, which has not been benchmarked in this specific context, might not be the ideal fit. Atlas allows you to switch the active model and provider on the fly, making it easy to experiment and find the best tool for each task.

Setup

01Export your Upstage API key as an environment variable: `export UPSTAGE_API_KEY="your_api_key_here"`.
02Confirm Atlas resolves the three Upstage Solar models by running: `atlas models upstage`.
03Configure your primary model in `atlas.json` by pinning: `"model": "upstage/solar-pro3"`.
04Configure your small model in `atlas.json` by pinning: `"small_model": "upstage/solar-mini"`.
05Keep changes scoped and lean on Atlas's unified-diff review rather than whole-file rewrites, due to the 8,192 token output cap on Solar Pro models.

Frequently asked questions

What is the cost of Upstage Solar Pro 3 in Atlas?: Upstage Solar Pro 3 is priced at $0.25 per Mtok for both input and output, offering symmetric pricing that makes verbose agent turns more economical within Atlas.
What is the context window for Upstage Solar Pro 3?: Upstage Solar Pro 3 provides a substantial 131,072 token context window, doubling the capacity of Solar Pro 2 while maintaining the same price point.
Can Upstage Solar handle large file rewrites in Atlas?: Upstage Solar Pro models have a maximum output of 8,192 tokens, and solar-mini has 4,096 tokens. This means large single-shot file rewrites will not fit, so Atlas's unified-diff review is crucial for managing changes.
Is solar-mini a good choice for a `small_model` in Atlas?: Yes, solar-mini is an excellent choice for a `small_model` in Atlas, offering a 32,768 token window at a competitive $0.15/$0.15 per Mtok, and it is tuned for Korean and document extraction.
How does Upstage Solar's pricing compare to other models for Atlas?: Upstage Solar's symmetric pricing, where input and output cost the same ($0.25/$0.25 per Mtok for Pro 3), is rare. This contrasts with many other providers where output tokens can be 4x to 10x more expensive.
What are the steps to set up Upstage Solar in Atlas?: To set up Upstage Solar, export your `UPSTAGE_API_KEY`, run `atlas models upstage` to confirm resolution, and then pin `"model": "upstage/solar-pro3"` and `"small_model": "upstage/solar-mini"` in your `atlas.json` configuration.
Is Upstage Solar benchmarked against frontier models like GPT-5?: Upstage Solar has not been benchmarked head-to-head with frontier-tier models like Claude or GPT-5 on large-repo agentic coding tasks. It offers three models but does not include a frontier tier.

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