HomeBlogPricingCareers
Field notes/Engineering/Harbor x TensorLake: Infrastructure for Agentic Evals

Harbor x TensorLake: Infrastructure for Agentic Evals

TensorLake is now integrated as a first-class environment provider in Harbor, enabling scalable agent evaluation with secure ephemeral MicroVMs.

SBX-01C4SBX-01E3SBX-0202SBX-0221SBX-0240SBX-025FSBX-027ESBX-029DSBX-02BCSBX-02DBSBX-02FASBX-0319SBX-0338SBX-0357SBX-0376[ RUNTIME: ACTIVE ] P50 2.45S · P99 4.12S · 5M/PROJECT

What is TensorLake?

TensorLake is a specialized compute infrastructure for AI agents. It provides stateful sandbox infrastructure with dynamic capabilities for deploying agents and creating RL environments:

  • MicroVM Isolation: Firecracker VMs with sub-200 millisecond startup time
  • Stateful Suspend and Resume: Sandboxes suspend automatically when finished and resume for debugging or task reuse
  • Clone: Running sandboxes can be cloned across the cluster to replicate environments after setup

Key Integration Features

1. Drop-in Scalability

Scale from 1 to 1,000 concurrent agents instantly. Switching to TensorLake in Harbor requires only a CLI flag change:

harbor run --task-name [my-benchmark] --dataset [my-dataset] --env tensorlake

2. MicroVM Security

TensorLake uses MicroVMs to ensure complete isolation of agent-executed code from host infrastructure. This is critical when evaluating agents on untrusted code or complex benchmarks where potentially dangerous actions might be valid test cases.

3. Resource Control & GPU Support

The integration supports fine-grained resource control directly from Harbor config:

  • Compute: Configurable vCPUs and RAM
  • Storage: Ephemeral disk sizing
  • GPUs: Native support for GPU-accelerated workloads, essential for agents performing local inference or data science tasks

4. State Management with Snapshots

Harbor leverages TensorLake's snapshot capabilities. Evaluations can start from pre-warmed states, reducing setup time for complex environments requiring heavy dependency installation.

TensorLake vs. Other Environments

Why choose TensorLake?

  • vs. Daytona: While Daytona excels at persistent developer environments, TensorLake is optimized for the high-churn, ephemeral nature of agent loops where environments are created and destroyed rapidly
  • vs. E2B: Both offer excellent MicroVM sandboxing. TensorLake is distinct in broader ecosystem integration (Indexify) for extraction and workflow orchestration, making it strong for agents within larger data processing pipelines
  • vs. Modal: Modal excels at serverless GPU compute and batch ML jobs. TensorLake is optimized for stateful, long-running agent loops with native suspend/resume, live migration, and cloning that Modal doesn't support

Comparison Table

| Feature | E2B | Daytona | Modal | TensorLake | |---------|-----|---------|-------|-----------| | Primary Use Case | Code Execution | Dev Environments | Serverless Compute | Agent Infrastructure | | Cold Start Time | ~2s | ~150ms | ~500ms | MicroVM | | Filesystem | 1x Baseline | ~3.3x Baseline | 2x Baseline | 5x Baseline | | Auto Suspend/Resume | Yes | No | No | Yes | | Clone Sandboxes | No | No | No | Yes | | Point-in-Time Snapshots | No | Filesystem only | Alpha (7d TTL) | Yes | | Stateful Execution | Partial | Partial | Partial | Native | | Live Migration | No | No | No | Automatic | | GPU Support | No | No | Yes | Yes | | Scale Limit | Hundreds | Not Published | Thousands | Millions | | Bring Your Own Cloud | No | No | No | Yes | | Persistence | Ephemeral | Persistent Workspaces | Ephemeral | Snapshots & Ephemeral |

Getting Started

1. Install the SDK

pip install tensorlake

2. Set your API Key

export TENSORLAKE_API_KEY="tl_..."

3. Run your first task

harbor run --env tensorlake --task-name adaptive-rejection-sampler --dataset terminal-bench@2.0 --agent claude-code --model anthropic/claude-sonnet-4-6

Debugging

Access TensorLake's native debugging tools through Harbor:

harbor env attach <session_id>

This drops you directly into the running sandbox shell to observe agent behavior.

TT
WRITTEN BYTensorlake TeamEngineering
◆ FIELD NOTES — WEEKLY

Engineering posts, in your inbox.

One dispatch per week from the Tensorlake team — runtime deep-dives, product updates, and the occasional benchmark that surprised us.