How to build agents with filesystems and bash
By Steven Van ·
Vercel's open-source bash-tool lets agents explore data as files, cutting one internal agent's cost from $1.00 to $0.25 per call.
Vercel has open-sourced bash-tool, a sandboxed tool that gives agents filesystem and bash access instead of custom retrieval pipelines. Structure data as files (customer records, tickets, transcripts, CRM data) and the agent explores it the way it already navigates code: it lists directories, greps for relevant sections, and reads only what it needs.
Vercel says its sales call summarization agent dropped from about $1.00 to about $0.25 per call on Claude Opus 4.5 after the switch, with improved output quality. It used the same approach for d0, its text-to-SQL agent.
The announcement includes a Sales Call Summary template that deploys with one click, showing the file structure an agent explores, including call transcripts, CRM records, Slack history and a sales playbook, to produce a summary with objections and action items.
