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BuildMidAI engineeringAuto-graded

Write a prompt that extracts JSON from emails

Getting a reliable, checked result out of a language model on messy input is what this measures.Build a prompt that reliably pulls structured data out of messy customer-support emails. Reliability is the whole problem: the emails are inconsistent, and a prompt that works on three examples will fail on the fourth. You need a schema the model is told to honour, examples that show it the shape, validation of what comes back, and a retry path for when the output is unusable.
30 min
prompting

You're done when

  • The prompt uses a system prompt to establish the model's role and constraints.
  • The target schema is stated explicitly in the prompt.
  • Examples are included so the model can see the expected shape.
  • The returned JSON is validated rather than trusted.
  • Output that fails validation triggers a retry instead of propagating downstream.
  • Structural delimiters separate instructions from the email content.

What it measures

Prompt engineeringConstructing a prompt whose reliability comes from its structure rather than from careful wording alone.
Generative AITreating model output as untrusted — validated, retried, and only then used.
Designing for the bad outputPlanning for the case where the model returns something unusable, which is what separates a demo prompt from a production one.

Your environment

Terminal + editorA full shell in the browser
Claude CodePre-authenticated, no key setup
Isolated microVMYours alone, wiped afterwards

Start this lab

30 min
Start labYou'll sign in to Anthropos to start. The lab opens in a private cloud workspace with Claude Code ready to use.
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