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Integrate the TypeScript SDK

DynoCap provides a native TypeScript/JavaScript SDK (@dynocap/sdk) for developers building AI agent harnesses, automated evaluators, or developer tool integrations.

The SDK communicates directly with the local user daemon over UNIX domain socket ~/.dynocap/daemon.sock (mode 0600).

Installation

Within the dynocap repository or a local workspace linking the package:

JSON
{
  "dependencies": {
    "@dynocap/sdk": "file:./sdk/typescript"
  }
}
Shell
npm install

Pattern 1: Managing Project Tasks (Task API)

The Task class provides the full project lifecycle: cloning a workspace, executing commands, streaming output, previewing diffs, and exporting results.

TypeScript
import { Task, SandboxError } from "@dynocap/sdk";

async function runAgent() {
  try {
    // 1. Start a task with an imported project directory
    const task = await Task.start({
      name: "pr-fixer",
      projectPath: "./my-project",
      runtimes: [{ name: "node", version: "24" }],
      network: "none", // offline by default
      ttlSeconds: 1800, // 30-minute sandbox lifetime
    });

    console.log(`Spawned task ${task.id} (name: ${task.name})`);

    // 2. Execute a command in /workspace
    const result = await task.exec("npm test", {
      timeoutSeconds: 60,
    });

    console.log(`Exit code: ${result.exitCode}`);
    console.log(`Stdout: ${result.stdout}`);

    // 3. Inspect a real-time diff preview
    const preview = await task.diff();
    console.log(`Verified patch path: ${preview.patchPath}`);

    // 4. Finish the task: exports result & destroys the VM
    const finished = await task.finish();
    console.log(`Final patch exported to: ${finished.patchPath}`);
    console.log(`Result directory: ${finished.resultDirectory}`);
  } catch (error) {
    if (error instanceof SandboxError) {
      console.error(`DynoCap error [${error.kind}]: ${error.message}`);
    } else {
      throw error;
    }
  }
}

runAgent();

Pattern 2: Raw Ephemeral Sandboxes (Sandbox API)

If you only need an isolated minimal Linux execution environment without importing a project workspace or generating diffs, use Sandbox:

TypeScript
import { Sandbox } from "@dynocap/sdk";

async function executeInSandbox() {
  // Boot raw sandbox
  const sandbox = await Sandbox.create({
    name: "eval-box",
    cpus: 2,
    memoryMB: 1024,
    network: "none",
    ttlSeconds: 300,
  });

  // Run command
  const execResult = await sandbox.exec("uname -a && cat /etc/alpine-release", {
    timeoutSeconds: 10,
  });

  console.log(execResult.stdout);

  // Clean up
  await sandbox.destroy();
}

Re-attaching to Existing Tasks

Tasks can be re-opened by their friendly name or immutable ID across different processes:

TypeScript
import { Task } from "@dynocap/sdk";

// Open existing task by name
const task = await Task.open("pr-fixer", {
  requireOffline: true, // throw if sandbox has network access enabled
});

// Run further commands
await task.exec("npm run build");

Streaming Standard Input & Terminal Transcripts

The SDK allows piping standard input bytes and capturing combined terminal transcripts:

TypeScript
// Pipe stdin bytes to a guest process
const inputBytes = new TextEncoder().encode("console.log(process.version);\n");
const res = await task.exec("node", {
  stdin: inputBytes,
});

// Run in a pseudo-terminal (PTY)
const ttyRes = await task.exec("npm test", {
  terminal: { rows: 24, cols: 80 },
});
// ttyRes.stdout contains combined terminal transcript (including ANSI controls)
console.log(ttyRes.stdout);

Listing and Housekeeping

Query managed sandboxes and purge expired tasks:

TypeScript
import { listManaged, removeManaged } from "@dynocap/sdk";

// List all active and retained tasks
const entries = await listManaged();
for (const entry of entries) {
  console.log(
    `${entry.name ?? entry.id}: phase=${entry.phase}, TTL=${entry.sandboxExpiresAtUnix}`
  );
}

// Purge a completed task and remove retained logs/results
await removeManaged("pr-fixer", { purge: true });

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