Attachments

Use the filesystem API to upload files, then include file references in prompt content.

1. Upload a file

   TypeScript

   import { SandboxAgent } from "sandbox-agent";
   import fs from "node:fs";
   
   const sdk = await SandboxAgent.connect({
     baseUrl: "http://127.0.0.1:2468",
   });
   
   const buffer = await fs.promises.readFile("./data.csv");
   
   const upload = await sdk.writeFsFile(
     { path: "./uploads/data.csv" },
     buffer,
   );
   
   console.log(upload.path);

   cURL

   curl -X PUT "http://127.0.0.1:2468/v1/fs/file?path=./uploads/data.csv" \
     --data-binary @./data.csv

   The upload response returns the absolute path.

2. Reference the file in a prompt

   const session = await sdk.createSession({ agent: "mock" });
   
   await session.prompt([
     { type: "text", text: "Please analyze the attached CSV." },
     {
       type: "resource_link",
       name: "data.csv",
       uri: "file:///home/sandbox/uploads/data.csv",
       mimeType: "text/csv",
     },
   ]);

Notes

• Use absolute file URIs in resource_link blocks.
• If mimeType is omitted, the agent/runtime may infer a default.
• Support for non-text resources depends on each agent’s prompt capabilities.