DeepSeek-R1 AI Chat: Access, Model Fit, and API Options

Short answer

“DeepSeek-R1 AI chat” can mean a chat experience associated with R1 or an API integration using the R1 model. Those are different things. DeepSeek’s official chat sign-in is available, but its current product information describes the app as using the latest flagship model—not as a selectable R1 chat. For a new production integration, DeepSeek’s current API reference lists deepseek-flash and deepseek-v4-pro as model choices. The API change log announced that the legacy deepseek-reasoner name would be discontinued on July 24, 2026; the current model list does not list it as a supported choice. Don’t rely on that legacy name for a new integration. (Chat Completions API)

How to use DeepSeek chat

For a ready-to-use assistant, use DeepSeek’s official chat sign-in or get the official app. Available product information describes the app as powered by DeepSeek’s “latest flagship model,” but does not establish that the current chat runs R1 or lets you select R1 by name. Deep-Think or another reasoning mode is a feature setting; its name alone does not verify which model is serving a conversation.

Choose the official chat or app if you want a convenient DeepSeek assistant and do not require the specific R1 model. If your research, evaluation, or application must use R1, check the serving provider’s exact model identifier rather than inferring it from the interface or a “thinking” feature.

Is R1 a good model for chat?

At launch, DeepSeek positioned R1 around reasoning work, including math and coding. That makes R1 a reasonable candidate to evaluate for multi-step problems, math questions, or code tasks. It does not establish that R1 is universally better for those tasks, better for ordinary conversation, or currently available through DeepSeek’s hosted chat or API. The available evidence here does not provide a comparable R1-versus-current-model benchmark or a verified R1 limitation list.

For ordinary chat, summarization, or drafting, there is no evidence here of a specific R1 advantage. If you need an official hosted API model for reasoning-oriented requests, DeepSeek documents thinking mode for deepseek-flash; that is a current alternative to evaluate, not proof that it matches R1. Test the candidate on representative prompts from your actual workflow before choosing it. (Thinking Mode)

Production API: use a currently documented model

DeepSeek’s current Chat Completions documentation specifies https://api.deepseek.com/chat/completions and lists deepseek-flash and deepseek-v4-pro as model choices. The official quick-start example uses a DeepSeek API key with Bearer authentication. The current pricing documentation identifies deepseek-flash as DeepSeek-V4.1-Flash-1017. These details describe the current API path; they do not provide a route to the R1 model. (Chat Completions API)

A separate R1-specific hosted API route is documented by Lambda: Lambda says DeepSeek-R1-0528 is available through its Inference API. Lambda’s general API example for another model uses the base URL https://api.lambda.ai/v1, a Lambda API key, and the /chat/completions path. However, the R1 announcement and model page do not specify the exact R1 API model string, account eligibility, or current pricing. Confirm those in Lambda’s current account or model documentation before integrating; do not assume a model ID or price from a third-party listing. (Lambda R1 model page; Lambda API example)

For DeepSeek’s currently listed models, an example using the documented chat-completions pattern is:

export DEEPSEEK_API_KEY="your-api-key"

curl https://api.deepseek.com/chat/completions \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer $DEEPSEEK_API_KEY" \
  -d '{
    "model": "deepseek-flash",
    "messages": [
      {"role": "user", "content": "Summarize the trade-offs in this proposal."}
    ],
    "stream": false
  }'

Thinking mode is enabled by default in the current documentation, with high as the default effort. If you set its OpenAI-format control explicitly, DeepSeek documents the thinking parameter; in Chat Completions, thinking-mode output may include reasoning_content alongside the final content. Use the final content for the user-facing answer, and review the current parameter guide before changing thinking settings or handling multi-turn/tool responses. (Thinking Mode)

API pricing and billing window

DeepSeek lists API rates in USD per 1 million tokens. For deepseek-flash, the current pricing table shows:

Token type	Off-peak	Peak
Input, cache miss	$0.15	$0.30
Input, cache hit	$0.003	$0.006
Output	$0.60	$1.20

The documented peak window is 01:00–04:00 and 06:00–10:00 UTC, Monday through Friday, excluding Chinese public holidays. All other times—including weekends and Chinese public holidays—are off-peak. These are API usage charges, not a consumer chat subscription price; check the live pricing table before budgeting because rates and model versions can change. This pricing is for DeepSeek’s listed Flash API model, not Lambda’s R1-0528 route.

Which route should you choose?

• You want a ready-to-use assistant: use DeepSeek’s official chat sign-in or official app; available product information does not verify that either is specifically R1.
• Your task involves math, coding, or multi-step reasoning: R1 is a reasonable candidate to evaluate based on its launch positioning, but that positioning is not comparative proof of superior performance. If you need a hosted DeepSeek API, evaluate a currently listed model such as deepseek-flash with thinking mode enabled.
• You need a production integration: use a model and identifier currently listed in the official API docs. The docs currently list deepseek-flash and deepseek-v4-pro, not R1; do not assume deepseek-reasoner still selects R1.
• You specifically require R1: Lambda documents DeepSeek-R1-0528 on its Inference API. Check Lambda’s current account or model documentation for the exact API model string, access conditions, and price before implementation; those details are not specified in Lambda’s R1 announcement. This is an API route, not proof that DeepSeek’s own consumer chat offers selectable R1.

Bottom line: R1’s launch positioning makes it worth considering for reasoning-heavy tasks, not an automatic winner for every chat. Use official chat when model identity is not critical. For a verified R1-specific hosted API lead, Lambda documents R1-0528 on its Inference API, but confirm the exact API identifier and commercial terms before production use. DeepSeek’s own current API list does not establish an R1 route.

Sources

DeepSeek API Docs — Your First API Call

DeepSeek API Docs — Thinking Mode

DeepSeek API Docs — Models & Pricing

DeepSeek API Docs — Chat Completions API

DeepSeek Chat — Sign in

DeepSeek — Download

DeepSeek-R1-0528: The Open-Source Titan Now Live on Lambda’s Inference API

DeepSeek R1 0528 | Lambda Inference

DeepSeek V3-0324 Live on Lambda