Giving bash to Brex's audit agent
summary
An audit agent is given a sandboxed shell and the company measures the impact: replacing verbose tool calls with just-bash shaves token usage dramatically, dropping from 200,000 tool calls to 60,000 Bash invocations for a $2.5M/month book of business and cutting calls by 75%. The system uses jq, grep and a filesystem-backed working memory so policies and receipts stay out of the LLM context, making audits faster and economically viable.
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chapters (9)
- 0:00The audit challenge: which 5%?
- 1:17Real expense policies are weird
- 2:30Creative abuse needs a creative agent
- 4:02The naive tool-calling trap
- 4:26"I'll replace you with a very small shell script"
- 5:35just-bash: a sandboxed shell for agents
- 8:11Unix philosophy and context management
- 12:36Hallucinated flags are feature requests
- 14:24Your agent is in the marble
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