Overview

Chalk Compute is a container runtime for running arbitrary workloads — AI agents, model inference, data pipelines, or any long-running process — in isolated, sandboxed environments. Workloads can run on Chalk’s managed serverless fleet or on your own EKS/GKE clusters.

To use Compute on a cluster, follow the Compute Setup guide.

Then install the SDK to get started:

pip install chalkcompute

Compute fits into the broader Chalk platform alongside the Context Engine and MCP Gateway. Your application talks to the platform from outside the VPC; all workload code, data sources, and credentials stay inside it.

Chalk Compute concepts and platform layers


Core components

Sandboxes

Every workload runs in a gVisor-isolated sandbox with its own filesystem, network namespace, and resource limits. Sandboxes support CPU and GPU workloads, enforce multi-tenant isolation at the kernel level, and can be deployed on managed infrastructure or self-hosted Kubernetes.

from chalkcompute import Container, Image

c = Container(image=Image.debian_slim(), cpu="2", memory="4Gi").run()
result = c.exec("python", "-c", "print('hello from a sandbox')")
print(result.stdout_text)
c.stop()

Containers

Containers wrap a sandbox with image building, file upload, secret injection, and an exec-style invocation API. Use a container for one-off batch jobs, interactive sessions, or long-running processes that don’t need replication.

from chalkcompute import Container, Image

c = Container(
    image=Image.debian_slim("3.12").pip_install(["requests"]),
    name="hello-container",
    cpu="1",
    memory="2Gi",
).run()

result = c.exec("python", "-c", "print('hello from a container')")
print(result.stdout_text)
c.stop()

Scaling Groups

Scaling Groups deploy a replicated, HTTP-fronted service with autoscaling and an automatically provisioned DNS name. Use them for inference servers, internal APIs, agent backends, and any long-lived service that needs to be reachable from outside the cluster.

from chalkcompute import ScalingGroup, Image

sg = ScalingGroup(
    image=Image.debian_slim("3.12").pip_install(["flask"]),
    name="hello-api",
    port=8080,
    min_replicas=1,
    max_replicas=3,
).deploy().wait_ready()

resp = sg.call("/health", method="GET")
print(resp.status_code, resp.text)
sg.delete()

Images

Images define the software environment for a sandbox. The Image API provides a fluent builder for installing pip packages, system dependencies, and local files. Images are content-addressed — identical specs share a cached build, and incremental changes only rebuild affected layers.

img = (
    Image.debian_slim("3.12")
    .pip_install(["torch", "transformers"])
    .run_commands(
        "apt-get update",
        "apt-get install -y ffmpeg",
    )
)

Volumes

Volumes provide persistent, versioned file storage backed by object storage. A Rust-based FUSE driver mounts volumes directly into containers as normal directories. Writes use batch copy-on-write semantics — changes are buffered locally and flushed on sync, giving other consumers a consistent view. Past versions are retained, enabling fork semantics for parallel agent workloads.

from chalkcompute import Container, Image, Volume

vol = Volume("training-data")
vol.put_file("inputs/example.txt", b"hello from a volume\n")

c = (
  Container(image=Image.debian_slim("3.12"), name="volume-demo")
   .mount_volume("training-data", "/data")
   .run()
)
result = c.exec("python3", "-c", "print(open('/data/inputs/example.txt').read())")
print(result.stdout_text)
c.stop()

Functions

Functions let you deploy a Python callable as a remotely invocable endpoint. Chalk handles image building, scaling, and routing — you write a function, deploy it, and call it from anywhere.

import chalkcompute

@chalkcompute.function(cpu="1", memory="1Gi")
def normalize_name(name: str) -> str:
    return " ".join(part.capitalize() for part in name.split())

normalize_name.wait_ready()
print(normalize_name("ada lovelace"))  # Ada Lovelace

Secrets

Inject secrets into sandboxes, containers, and functions via the Secret API. Secrets are resolved at deploy time and exposed to the workload as environment variables. The four factory constructors cover the common cases:

import os
from urllib.parse import urlparse

import chalkcompute
from chalkcompute import Secret

@chalkcompute.function(
   secrets=[
       Secret.from_env("OPENAI_API_KEY"),
       Secret.from_integration("prod_postgres"),
   ],
)
def call_api(prompt: str) -> str:
   openai_api_key = os.environ["OPENAI_API_KEY"]
   database_url = os.environ["DATABASE_URL"]

   headers = {"Authorization": f"Bearer {openai_api_key}"}
   db_host = urlparse(database_url).hostname
   # Pass headers to your OpenAI-compatible client and database_url to
   # your Postgres client.
   return f"ready to call OpenAI for {prompt!r} and log to {db_host}"

Security

The Security section of the Sandbox doc covers the identity and networking controls available for production workloads: workload identity federation (OIDC-compliant per-sandbox credentials), the MCP Gateway for proxying tool-use APIs without exposing real credentials, network policies for restricting egress, and WireGuard tunnels for private connectivity between workloads.


Choosing the right primitive

Chalk Compute is layered:

  • Core Infrastructure — the directly-invokable execution primitives. Sandboxes, Containers, and Scaling Groups each have their own SDK and can be used standalone — you do not need anything else to launch a workload.
  • Filesystem — the environment a workload brings with it and the state that persists across runs. Always combined with a Core Infrastructure primitive, never used on their own.
  • Chalk Catalog — Functions are Python callables deployed onto a Scaling Group and registered in the Chalk Catalog, so they are reachable from the rest of Chalk (Chalk SQL, the query server, ChalkDF via F.catalog_call) and pick up extra runtime controls like async invocation, streaming, concurrency limits, rate limiting, and request-based autoscaling.

The diagram below shows how these primitives sit inside a Chalk-managed deployment in your cloud account. Containers and scaling groups run on a gVisor-hardened nodepool; image builds, the function registry, secrets, and volumes are all reachable from the same VPC; clients can hit the API Server directly, the Envoy router for HTTP traffic into a scaling group, or the Function Queue for async invocations.

Chalk Compute deployment architecture

Core Infrastructure

The execution primitives — pick one based on how you need to drive and reach the workload.

Use caseUse
Direct gRPC stream control over a process (stdin, signals, streaming stdout/stderr)Sandbox
Drive a workload with exec calls (interactive shell, batch CLI, IDE-style sessions)Container
Single long-running process you don’t need to replicateContainer with port
Replicated HTTP service with autoscaling and a public DNS nameScalingGroup

Filesystem

Define the software environment and the persistent storage available to a workload. Always used together with a Core Infrastructure or Functions primitive, never on their own.

Use caseUse
Define the software environment baked into a workload (pip packages, system deps, local files)Image
Persistent, versioned, copy-on-write storage shared across workloads or runsVolume

Chalk Catalog

Functions deploy a Python callable onto a Scaling Group and register it in the Chalk Catalog. Once registered, the callable is reachable from the rest of Chalk — call it from Chalk SQL, from a resolver, from the query server, or from a DataFrame via F.catalog_call(). Functions also pick up runtime features that the underlying Scaling Group does not provide on its own: async invocation, streaming results, nested calls, automatic retries, concurrency caps, rate limits, and request-queue-driven autoscaling.

Reach for a Function when the workload needs to participate in the feature engine, or when you want those runtime controls without wiring them yourself on a Scaling Group.

Use caseUse
Python callable reachable from Chalk SQL, resolvers, the query server, or a DataFrameFunction
Async / streaming / nested calls with batching, retries, concurrency, or rate-limit controlsFunction