Simon Willison’s Weblog

Kim_Bruning on Hacker News:

But seriously, you can put a shebang on an english text file now (if you're sufficiently brave) [...]

This inspired me to look at patterns for doing exactly that with LLM. Here's the simplest, which takes advantage of LLM fragments:

#!/usr/bin/env -S llm -f
Generate an SVG of a pelican riding a bicycle

But you can also incorporate tool calls using the -T name_of_tool option:

#!/usr/bin/env -S llm -T llm_time -f
Write a haiku that mentions the exact current time

Or even execute YAML templates directly that define extra tools as Python functions:

#!/usr/bin/env -S llm -t
model: gpt-5.4-mini
system: |
  Use tools to run calculations
functions: |
  def add(a: int, b: int) -> int:
      return a + b
  def multiply(a: int, b: int) -> int:
      return a * b

Then:

./calc.sh 'what is 2344 * 5252 + 134' --td

Which outputs (thanks to that --td tools debug option):

Tool call: multiply({'a': 2344, 'b': 5252})
  12310688

Tool call: add({'a': 12310688, 'b': 134})
  12310822

2344 × 5252 + 134 = **12,310,822**

Read the full TIL for a more complex example that uses the Datasette SQL API to answer questions about content on my blog.