capability-worker

name	capability-worker
description	Handles sandbox (Daytona/E2B), browser automation (Steel), computer use, and tier gating

Capability Worker

NOTE: Startup and cleanup are handled by worker-base. This skill defines the WORK PROCEDURE.

When to Use This Skill

Features involving: Daytona SDK integration, E2B sandbox fallback, Steel.dev browser automation, Anthropic Computer Use, tier gating middleware.

Required Skills

None.

Work Procedure

1. Read context: Read mission.md, .factory/library/architecture.md, .factory/research/daytona.md (for Daytona features). Read existing tier enforcement at services/api/src/middleware/tier-enforcement.ts and tiers config at services/api/src/config/tiers.ts.

2. Write tests first (TDD): Mock external SDK calls. Test the service interface, error handling, session management, and tier gating.

3. Sandbox services: Create a common interface and two implementations:

   interface SandboxService {
     createSandbox(opts: SandboxOpts): Promise<Sandbox>;
     execCommand(sandboxId: string, cmd: string): Promise<ExecResult>;
     writeFile(sandboxId: string, path: string, content: string): Promise<void>;
     readFile(sandboxId: string, path: string): Promise<string>;
     destroySandbox(sandboxId: string): Promise<void>;
   }
   

   • services/api/src/sandbox/daytona.ts — primary, uses @daytona/sdk
   • services/api/src/sandbox/e2b.ts — fallback, uses @e2b/code-interpreter
   • services/api/src/sandbox/index.ts — router that tries Daytona first, falls back to E2B

4. Browser tool: Use steel-sdk at services/api/src/tools/browser.ts. Export: navigate, screenshot, click, type, extract. Register in tool registry with compensatable class.

5. Computer use: At services/api/src/tools/computer-use.ts. Uses Daytona desktop sandbox for isolation. Implements Anthropic Computer Use API pattern (screenshot → coordinate interaction).

6. Tier gating: Create services/api/src/middleware/tier-gate.ts that checks user tier and returns 403 with upgrade prompt for Free tier users accessing Pro+ features.

7. Handle missing credentials gracefully: All capability services must check for env vars and return clear "not configured" errors if API keys are missing. Never crash on missing credentials.

8. Verify:

   • All tests pass
   • bun run build passes
   • biome check . passes

Example Handoff

{
  "salientSummary": "Built Daytona sandbox service with createSandbox/execCommand/writeFile/readFile/destroySandbox, E2B fallback with same interface, sandbox router with Daytona-first fallback logic, and tier-gate middleware. 22 tests passing.",
  "whatWasImplemented": "services/api/src/sandbox/daytona.ts, services/api/src/sandbox/e2b.ts, services/api/src/sandbox/index.ts (router), services/api/src/middleware/tier-gate.ts. All sandbox services implement common SandboxService interface.",
  "whatWasLeftUndone": "",
  "verification": {
    "commandsRun": [
      { "command": "cd services/api && bunx vitest run src/sandbox/ src/middleware/tier-gate", "exitCode": 0, "observation": "22 tests passed" },
      { "command": "bun run build", "exitCode": 0, "observation": "Clean build" }
    ],
    "interactiveChecks": []
  },
  "tests": {
    "added": [
      { "file": "services/api/src/sandbox/__tests__/daytona.test.ts", "cases": [
        { "name": "createSandbox returns sandbox with ID", "verifies": "Sandbox creation" },
        { "name": "auto-cleanup after TTL", "verifies": "Session management" }
      ]}
    ]
  },
  "discoveredIssues": []
}

When to Return to Orchestrator

• SDK has breaking API changes from documented version
• Tier configuration needs a decision (what features map to which tier)
• External service requires account setup not yet done