Using LLM in the shebang line of a script

11th May 2026

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.

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