DeepSeek Reasoner API
DeepSeek Reasoner API (DeepSeek R1) is an advanced reasoning model with built-in chain-of-thought capabilities. It excels at complex problem-solving, mathematical reasoning, and multi-step logic tasks. Access it on EvoLink with the documented model enum.
PRICING
| PLAN | CONTEXT WINDOW | MAX OUTPUT | INPUT | OUTPUT | CACHE READ |
|---|---|---|---|---|---|
| DeepSeek Reasoner | 128.0K | 65.5K | $0.278 $0.278Official Price | $0.417 $0.417Official Price | $0.028 $0.028Official Price |
Pricing Note: Price unit: USD / 1M tokens
Cache Hit: Price applies to cached prompt tokens.
DeepSeek Reasoner API for Complex Problem-Solving
DeepSeek Reasoner (R1) brings frontier-level reasoning at a competitive price point. With built-in chain-of-thought, 128K context window, and strong performance on math and logic benchmarks, it is the go-to model for tasks that require deep, step-by-step reasoning.
What can you build with the DeepSeek Reasoner API?
Complex Reasoning Systems
DeepSeek Reasoner API is built for tasks that require multi-step logical reasoning. Its chain-of-thought capability makes it ideal for research assistants, decision support systems, and analytical tools that need to break down complex problems systematically.
Math & Science Applications
DeepSeek Reasoner delivers strong performance on mathematical reasoning benchmarks. Use it for math tutoring systems, scientific computation assistants, and technical problem-solving tools that require precise, step-by-step calculations.
Code Analysis & Debugging
With its reasoning capabilities, DeepSeek Reasoner excels at understanding complex codebases, tracing bugs through multiple layers, and providing detailed explanations of code behavior. It is particularly effective for debugging and architectural analysis.
Why teams choose the DeepSeek Reasoner API
DeepSeek Reasoner API delivers advanced reasoning capabilities with built-in chain-of-thought at a fraction of the cost of comparable reasoning models.
Built-in Chain-of-Thought
Native chain-of-thought reasoning enables transparent, step-by-step problem solving without complex prompting.
Strong Math & Logic Performance
Competitive results on mathematical reasoning and logic benchmarks, suitable for technical and scientific applications.
Cost-Effective Reasoning
Advanced reasoning capabilities at significantly lower cost than comparable models from other providers.
How to integrate the DeepSeek Reasoner API
Use the EvoLink API with the documented model enum and required fields. DeepSeek Reasoner is fully compatible with the OpenAI SDK — just change the base URL.
Step 1 — Authenticate
Create an EvoLink API key and send requests with Bearer token authentication.
Step 2 — Set required fields
Provide model: deepseek-reasoner, and a messages array with role and content fields.
Step 3 — Tune outputs
Adjust temperature, top_p, max_tokens, stop, stream, and other parameters for your use case.
Core DeepSeek Reasoner API capabilities
Model facts from DeepSeek, plus EvoLink access details
Chain-of-Thought Reasoning
Built-in chain-of-thought enables the model to break down complex problems into logical steps, producing transparent and verifiable reasoning traces.
128K Context Window
Process long documents, complex problem descriptions, and multi-turn reasoning conversations within a single request.
Prompt Caching
Built-in prompt caching reduces costs for repeated system prompts and prefixes, ideal for production reasoning workloads.
OpenAI SDK Compatible
Fully compatible with the OpenAI SDK. Switch to DeepSeek Reasoner by changing the base URL and model name — no code rewrite needed.
Math Benchmark Performance
Strong results on MATH, GSM8K, and other mathematical reasoning benchmarks, demonstrating reliable quantitative reasoning.
Transparent Reasoning
The model's reasoning process is visible in its output, making it easy to verify logic and identify errors in complex analyses.
DeepSeek Reasoner API FAQs
Everything you need to know about the product and billing.