Infrastructure

Best Code Execution APIs for AI Products in 2026

Code execution APIs have become foundational infrastructure for AI products. As AI agents, coding assistants, and automated workflows generate and run code autonomously, the underlying execution layer determines whether your product can scale securely, respond quickly, and handle diverse computational demands. Choosing the right AI infrastructure platform directly impacts your product's capabilities, security posture, and operational costs.

Modal TeamEngineering
May 202618 min read
Best code execution APIs for AI products

Code execution APIs have become foundational infrastructure for AI products. As AI agents, coding assistants, and automated workflows generate and run code autonomously, the underlying execution layer determines whether your product can scale securely, respond quickly, and handle diverse computational demands. The broader serverless architecture market was estimated at $8.01 billion in 2022 and is projected to reach $50.86 billion by 2031. With a substantial and growing share of startups integrating LLMs into their core architecture, choosing the right AI infrastructure platform directly impacts your product's capabilities, security posture, and operational costs. This guide examines seven code execution APIs serving AI products in 2026, starting with Modal, a serverless compute platform built for secure sandboxed execution, instant autoscaling, and broad GPU support for AI workloads.

Key Takeaways

  • Secure sandboxed execution protects against untrusted code: AI products generate and run code autonomously, making isolation critical. Modal uses gVisor containers while E2B employs Firecracker microVMs for secure isolation
  • A code-first SDK accelerates AI development: Modal's decorator-based SDK eliminates YAML configuration and supports all programming languages and runtimes, enabling faster iteration cycles for AI product teams
  • GPU access differentiates AI-capable platforms: Modal supports a broad GPU lineup including H100, B200, and A100 variants, while platforms like E2B and AWS Lambda focus on CPU-only workloads
  • Autoscaling handles unpredictable AI workloads: Modal's Team plan scales to 1,000 containers, with custom limits for Enterprise, critical for AI products with variable demand patterns
  • Production-proven platforms reduce operational risk: Modal powers over 10,000 teams including AI companies building coding agents, inference pipelines, and batch processing systems

1. Modal

Modal delivers serverless compute designed specifically for AI workloads: inference, training, batch processing, and secure sandboxed execution. The platform takes your code, containerizes it, and executes it in the cloud with automatic scaling, all defined through a code-first SDK.

Core Capabilities

  • gVisor container isolation: Secure sandboxed execution for running AI-generated code, with compute jobs containerized and virtualized using gVisor
  • Instant autoscaling: Scale from zero to 1,000 containers on Team plans, with custom Enterprise limits, handling traffic spikes without pre-provisioning infrastructure
  • Code-first SDK: Define compute, storage, and networking via decorators with no YAML configuration required. The SDK supports Python, Go, and JavaScript/TypeScript, and sandboxes can run any programming language or runtime your workload requires
  • Broad GPU portfolio: Access to NVIDIA GPUs including H100, B200, H200, A100 variants, enabling everything from lightweight inference to large-scale model training
  • Fast cold starts: Engineered for fast cold starts and faster feedback loops, with an optimized filesystem that helps containers come online quickly without letting large images slow startup down. Memory Snapshots (currently in alpha) and additional filesystem optimizations can further reduce latency for initialization-heavy workloads

Security and Compliance

Modal has completed SOC 2 Type II certification and supports HIPAA-compliant workloads on Enterprise plans via a BAA. The platform uses gVisor-based sandboxing for compute isolation, TLS 1.3 for public APIs, and encryption for data in transit and at rest.

Production-Ready Infrastructure

Modal's AI-native architecture includes a custom-built container runtime, scheduler, and file system optimized for AI workloads. Key infrastructure features include:

  • Memory Snapshots: Captures CPU memory state to reduce cold start latency; GPU Memory Snapshots are available as an alpha feature
  • Multi-cloud capacity pool: Modal pools hardware across multiple clouds to improve GPU availability without requiring quotas or reservations
  • Distributed primitives: Built-in Queues and Dicts for coordinating complex AI workflows
  • Volumes: Modal's distributed filesystem for model weights and datasets; for large datasets with many small files, follow Modal's dataset-ingestion guidance

Best For: Teams building AI products that need secure code execution at scale, with on-demand GPU access for inference, training, or compute-intensive analysis, especially those seeking production-grade infrastructure with proven enterprise scale.

2. E2B

E2B specializes in secure sandboxes for AI agents, focusing on ephemeral code execution with Firecracker microVM isolation. E2B claims it is used by 88% of Fortune 100 companies for frontier agentic workflows.

Core Capabilities

  • Firecracker microVMs: Hardware-level isolation for running untrusted AI-generated code
  • Supports cold starts: E2B supports cold starts, with microVM technology designed to bring sandboxes online quickly
  • Multi-language SDKs: Support for Python and TypeScript/JavaScript integration patterns
  • Template system: Reproducible sandbox environments with versioning for consistent execution

Architecture Approach

E2B excels at ephemeral code execution, spinning up isolated environments for agents to run generated code, then tearing them down. E2B Pro includes 100 concurrent sandboxes, with paid extra concurrency available up to 1,100, and 24-hour session limits even on Pro plans.

Use Case Focus

The platform is purpose-built for AI agent sandboxes where code execution needs hardware-level isolation. E2B's SDK design provides clean interfaces for common agent patterns including code generation, testing, and iterative development workflows.

Best For: Teams building AI agents focused on CPU-based code execution and testing where GPU acceleration is not required, particularly those needing fast sandbox cold starts and Fortune 100-proven reliability.

3. Northflank

Northflank provides a complete workload runtime platform with multiple isolation technologies, including Kata Containers, gVisor, and Firecracker options. Northflank says it processes 2M+ isolated workloads monthly and cites customers including Sentry and Writer.

Core Capabilities

  • Multiple isolation options: Choice of Kata Containers, gVisor, or Firecracker based on security and performance requirements
  • Unlimited session duration: No timeout constraints for persistent agents and long-running workloads
  • BYOC deployment: Self-serve deployment to AWS, GCP, Azure, or bare-metal infrastructure
  • GPU support: Access to GPUs including H100 for ML workloads
  • Any OCI image: Standard container image support without vendor lock-in

Architecture Approach

Northflank offers a complete platform combining sandboxes, APIs, databases, and GPUs in one environment. The platform supports persistent storage volumes from 4GB to 64TB for workloads requiring data persistence across sessions.

Production Considerations

Northflank supports fast microVM boot times for its sandboxes, with actual environment creation time varying depending on image and configuration. The platform's strength lies in its flexibility, as teams can choose their isolation technology, deployment model, and infrastructure configuration.

Best For: Teams building AI products that require BYOC deployment, unlimited session duration, or need to run workloads in their own cloud infrastructure with enterprise-grade security controls.

4. Daytona

Daytona provides persistent development environments and has shifted its focus toward AI sandboxes, widely reported by third parties as occurring in early 2025. The platform supports cold starts engineered for rapid sandbox creation.

Core Capabilities

  • Fast sandbox creation: Daytona supports rapid sandbox creation with cold starts engineered for quick spin-up
  • Persistent workspaces: Sandboxes can be configured for extended runtime with state preservation
  • Enterprise and on-prem deployment: Enterprise/on-prem and customer-managed deployment options are available; custom regions and self-hosted runners were described as invite-only experimental in January 2026 release notes
  • Multi-language SDKs: Support for Python, Ruby, and Go integration patterns
  • Docker/OCI compatibility: Daytona's docs describe OCI/Docker-compatible sandboxes with a dedicated kernel, filesystem, and network resources for flexible environment configuration

Architecture Approach

Daytona focuses on persistent workspaces that maintain state across sessions. This approach benefits AI products that need to preserve context, cached dependencies, or intermediate results without recreation overhead.

Compliance and Security

Daytona lists SOC 2, HIPAA, and GDPR-related trust and compliance materials; regulated use cases still require customer-side controls and contractual review.

Best For: Teams building AI products that require optimized cold starts, persistent development environments, and prefer workspace continuity over ephemeral execution.

5. RunPod

RunPod is a GPU cloud provider focused on AI and machine learning workloads. The platform offers a broad GPU catalog with per-second billing. RunPod's FlashBoot technology is designed to significantly accelerate cold start performance.

Core Capabilities

  • Extensive GPU selection: A broad GPU catalog including B200, H200, H100, A100, L40S, L4, and RTX-series options
  • Per-second billing: Pay for actual compute time without minimum usage requirements
  • Container-based execution: Standard container support for deploying AI workloads
  • Serverless and dedicated options: Choice between serverless endpoints and reserved GPU capacity
  • Community Cloud option: Access to lower-cost GPU capacity for non-critical workloads

Use Case Focus

RunPod excels at GPU-heavy workloads including model inference, training, and fine-tuning. The platform's A100 and H100 availability makes it suitable for running large language models and other compute-intensive AI workloads.

Architecture Considerations

The platform provides REST API access for programmatic control but focuses primarily on GPU workloads rather than general-purpose code execution sandboxes. Teams needing CPU-based code execution alongside GPU inference may need to combine RunPod with other platforms.

Best For: Teams building AI products with GPU-heavy requirements including model serving, training, and inference at scale, particularly those prioritizing GPU availability and broad hardware selection.

6. AWS Lambda

AWS Lambda is Amazon's serverless compute service that integrates deeply with the AWS ecosystem and offers mature enterprise compliance programs.

Core Capabilities

  • Always-free tier: 1 million free requests and 400K GB-seconds monthly
  • AWS Firecracker isolation: MicroVM-based isolation for secure code execution
  • Compliance coverage: AWS Lambda is in scope for multiple AWS compliance programs, including SOC, PCI, FedRAMP, and HIPAA-eligible workloads, subject to AWS shared-responsibility obligations
  • AWS ecosystem integration: Native connections to SageMaker, Bedrock, S3, and other AWS services
  • EventBridge scheduling: Built-in cron and event-driven execution patterns

Architecture Constraints

Lambda enforces a 15-minute timeout for function execution, which impacts long-running AI workloads. Lambda does not expose native GPU accelerator configuration; AWS GPU inference is typically handled through services such as SageMaker, EC2, ECS/EKS, or Batch.

Use Case Focus

Lambda works well for event-driven AI workflows, API backends, and data processing pipelines that fit within its execution constraints. Teams with existing AWS commitments can leverage Lambda alongside other AWS AI services.

Best For: Teams building AI products within the AWS ecosystem that need event-driven execution, enterprise compliance, and integration with AWS AI services like SageMaker and Bedrock.

7. Replicate

Replicate provides a platform for running machine learning models via API. The platform focuses on model deployment and inference rather than general-purpose code execution, with a library of pre-built models and support for custom model deployment.

Core Capabilities

  • Model API deployment: Deploy machine learning models as API endpoints
  • Pre-built model library: Access to community-contributed models for common AI tasks
  • Custom model support: Deploy your own models using Cog, Replicate's containerization tool
  • Autoscaling inference: Automatic scaling based on request volume
  • Python client SDK: Programmatic access for integrating model inference into applications

Architecture Approach

Replicate differs from general-purpose code execution APIs by focusing specifically on model serving. The platform handles containerization, scaling, and API management for ML models, abstracting away infrastructure concerns.

Use Case Focus

The platform excels at scenarios where teams need to run specific ML models without managing inference infrastructure. This includes image generation, audio processing, and text analysis workloads where pre-trained or custom models provide the core functionality.

Best For: Teams building AI products that primarily need to run ML model inference via API, particularly those who want to leverage pre-built models or deploy custom models without managing inference infrastructure.

Why Modal Stands Out for AI Product Code Execution

Purpose-Built for AI Workloads

Modal's architecture is specifically engineered for AI and machine learning workloads. The platform's custom container runtime, scheduler, and file system are optimized for the unique demands of AI products: secure sandboxed execution, instant autoscaling, GPU-accelerated computation, and dynamic scaling based on demand.

Secure Sandboxed Execution at Scale

AI products that generate and execute code need robust isolation. Modal's sandboxes support 50,000+ concurrent sessions with fast startups, gVisor isolation, and full observability. Sandboxes are not limited to any single programming language. They can run any runtime or language the workload requires. This enables AI products to run untrusted code safely while maintaining visibility into execution behavior.

Comprehensive GPU Access

Unlike CPU-only platforms, Modal provides on-demand access to a broad GPU lineup, ranging from T4 and L4 through H100, H200, and B200. AI products can match compute to workload requirements, running lightweight inference on smaller GPUs while scaling to the latest hardware for demanding tasks like model training or large language model serving.

Developer Experience Without Compromise

The code-first SDK eliminates infrastructure configuration overhead. Teams define compute requirements, container images, and scaling behavior via decorators, and can integrate using Python, Go, or JavaScript/TypeScript. This approach enables rapid iteration without managing YAML configurations, Kubernetes clusters, or cloud provider consoles.

Production-Proven Scale

Modal powers cloud infrastructure for over 10,000 teams, including AI companies building production applications. The platform handles inference, training, batch processing, and sandboxed execution at enterprise scale, with SOC 2 Type II certification and support for HIPAA-compliant workloads on Enterprise plans via a BAA.

Enterprise Security and Compliance

With SOC 2 Type II certification, HIPAA-compliant workloads on Enterprise plans via a BAA, and comprehensive security practices including gVisor sandboxing and TLS 1.3, Modal meets the compliance requirements that production AI products demand.

For teams building AI products that require secure code execution, broad GPU access, and production-grade reliability, Modal's combination of AI-native infrastructure, sandboxed execution at scale, and proven enterprise capabilities makes it a strong choice.

Explore the Modal documentation to get started.

Explore the Modal documentation to get started building secure AI product infrastructure.

View Modal Docs

Frequently Asked Questions

What is a code execution API in the context of AI development?

A code execution API provides programmatic access to compute infrastructure for running code. In AI development, these APIs enable products to execute AI-generated code, run model inference, process data, and perform compute-intensive tasks without managing servers directly. Modal's serverless platform handles containerization, scaling, and resource management automatically.

How do sandboxed execution environments benefit AI products?

Sandboxed execution isolates code in secure environments where it cannot access host systems, other workloads, or sensitive data. For AI products that generate and run code autonomously (like coding assistants or AI agents), sandboxing prevents malicious or buggy code from causing damage. Modal's secure sandboxes provide gVisor-based isolation with full observability for monitoring execution behavior.

Can code execution APIs handle large-scale AI model training?

Yes, platforms with GPU support can handle model training workloads. Modal supports multi-node clusters (currently in beta) for training jobs, with access to H100, B200, and other high-performance GPUs. The platform's autoscaling capabilities allow teams to scale training jobs dynamically based on requirements without pre-provisioning infrastructure.

What are essential security features to look for in an AI code execution API?

Key security features include compute isolation (gVisor, Firecracker microVMs), network controls, encryption in transit and at rest, and compliance certifications. Modal provides gVisor-based sandboxing, TLS 1.3 for APIs, SOC 2 Type II certification, and support for HIPAA-compliant workloads on Enterprise plans via a BAA.

How does serverless computing impact the cost and scalability of AI development?

Serverless platforms eliminate idle capacity costs by scaling to zero when not in use and scaling up instantly when demand increases. Modal's scale-to-zero architecture means teams pay for compute they use or request, with no idle-resource charges, which can be more cost-effective than fixed infrastructure for AI products with variable or unpredictable workload patterns.

What role do AI coding agents play with code execution APIs?

AI coding agents use code execution APIs to run the code they generate, test implementations, and iterate on solutions. The execution API provides the secure, scalable infrastructure that agents need to operate autonomously. Modal's distributed primitives including Queues and Dicts enable coordination of complex multi-step agent workflows.

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