Tweet by 0xblacklight

March 24, 2026

lots of folks running expensive sandboxes but really all you need is a filesystem but really you don't even need a filesystem, you just need a filesystem API that frontends something like a database (often you care a lot about ACID compliance or indexability etc; @jeffreyhuber talks about this) you can do this with FUSE and lots of people are building really cool things this way but really you don't even need a filesystem API, because agents don't see the POSIX APIs they just see tokens in and tokens so really all you need is something that looks like a file system but frontends whatever you want - S3, Postgres, Chroma, durable streams, whatever coding agents are great "everything agents" but the problem is that you use an off-the-shelf harness it marries you to the filesystem so you get stuck with FUSE or NFS hacks OR you have to inject a bunch of extra MCP tools that are parallel to the 'real' fs tools but if you own the harness, you can own the control flow this lets you separate the tool INTERFACE from the tool EXECUTION. your tool can look like a normal FS read tool to the agent, but you can use whatever backend you want for the execution logic this unlocks lots of exciting things but it requires you build your own harness or use something more customizable

Author
0xblacklight
Date
March 24, 2026
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