The short answer

Start with the official chat for everyday questions. Choose the API or Harness when your task needs an integration or a workspace.

FOR: New DeepSeek users

Choose your entry point

The official website is deepseek.com and its chat service is chat.deepseek.com. This website is an independent guide: you sign in and manage your account on the official service, not here.

Use the official website to find the current app downloads. For an application or script, use the developer platform and API documentation. Harness is a separate agent environment for working with tools and a local workspace.

  • Ask and explore → official chat
  • Build an integration → API
  • Work with files and tools → Harness

Make the first task small and specific

A useful prompt gives the goal, the material to work with, and the shape of the answer. Start with something you can check, such as improving a short email or explaining a function you already understand.

Read the result before acting on it. Ask for a revision against one clear criterion instead of restarting with a vague request for a better answer.

TERMINAL
Summarize the text below for a new team member.
Return 3 key points and 1 open question.
Do not add facts that are not in the text.

[Paste your text here]

Move to the API when you need repeatability

An API is useful when another application needs to send prompts and consume the response. Keep the model identifier, token usage, and errors in your logs so that you can understand both behavior and cost.

A chat account, an API integration, and a third-party tool can have different billing and access rules. Check the relevant product before paying or entering credentials. Our pricing page explains the token-based API estimate.

Sources

Start with the original documents. Models and prices change; check the official pages before using them.

01DeepSeek official website02Official DeepSeek chat03DeepSeek API documentation04DeepSeek Harness