Code & AI agent sandboxes: read the guide

SlicerVM (Slicer)

HostedSandbox

Real Linux, in milliseconds — full Linux microVMs with systemd on your Mac, your servers, or your cloud.

Homepage Docs Pricing Repository

Scanned 23 Jul 2026 · Schema v5 · features v17

From: $25/mo per seat
Flat-rate commercial license (subscription) — per-seat (Individual/Team) and per-server (Platform). Self-hosted; zero usage metering.
Free tier: No
Card required.
Isolation: Firecracker microVM
shares only the hypervisor
Regions: —
SELF-HOSTED — there are NO vendor-operated regions. Placement is entirely the operator's choice: their Mac, Linux bare-metal (Hetzner, AWS Metal, PhoenixNAP, Vultr, Scaleway, OVHCloud, colo), mini PCs / Raspberry Pi, or a cloud VM with nested virt (GCE, Azure, OCI, DigitalOcean, AWS EC2). 'disclosed:false' reflects that region is not a product facet, not that it is hidden.
Capabilities: 17 / 54
4 partial · 12 fail · 7 not assessed
Agent readiness: 7/11 · 8/10
read · drive, pre-login surface

Advertised for

AI agent sandboxes / code execution · Coding agents (Claude Code, Codex, OpenCode) in an isolated root VM · K3s / HA Kubernetes clusters (dev, test, demos, autoscaling) · Long lived dev environments / homelabs · GPU inference & fine tuning · Remote BuildKit / CI · Code review bots

Built for

Developers, then technical

· CLI/API/SDK-first automation ('Automate VMs like API calls')
· code/terminal hero ('claude · ~/charts/app', shell snippets)
· deep vocabulary: microVMs, KVM, Firecracker, ZFS snapshots, VFIO, systemd, K3s/RBAC

01 Pricing Flat-rate commercial license (subscription) — per-seat (Individual/Team) and per-server (Platform). Self-hosted; zero usage metering.

Tier	EntryIndividual	Team	TopPlatform
Price	$25/mo (14-day free trial)per seat	$125/mo (5 seats; +$25/mo per extra seat)per seat	$250/mo per server
Includes	Full Slicer on your own hardware for personal projects, homelabs, or your day job. 2× concurrent daemons (Linux/WSL2/Mac), unlimited VMs per daemon, REST API + Go/TS SDK + CLI, egress filtering proxy, K3sup Pro, Discord community support. NOT for shared deployments.	5-seat baseline for teams to run Slicer on work devices; centralised billing. 2× daemons per seat, unlimited VMs per daemon, one seat per named developer. Same automation surface + egress proxy. NOT for shared deployments.	For shared infrastructure, internal systems, and customer-facing products (embed microVM sandboxes in a SaaS). Licensed per server — unlimited daemons + VMs per server. Private Discord channel + email support.
Seats	—	5	—
Seats overage	—	$25/seat	—

seat (Individual/Team) or server (Platform)·Card required: Yes·slicervm.com

Overages: Team: +$25/mo per extra seat beyond the 5-seat baseline. No usage/compute overages (flat license, self-hosted).

02 Runtime Each fact carries its source; dots show confidence. Open a row for the evidence.

Isolation & lifecycle

Isolation primitive

Firecracker microVMshares only the hypervisor

Persistence

both

Snapshots / forks

Yes

Resources & limits

Storage

ZFS-backed VM disks; persistent (Services, `storage: image`) or ephemeral (Sandboxes, cleaned on shutdown); VirtioFS folder sharing from host (Mac)

Limits & quotas

License-based (not usage-metered): Individual/Team = 2× concurrent Slicer daemons per seat, unlimited VMs per daemon; Platform = per-server license, unlimited daemons + VMs per server.

GPU

Yes

Access

Deploy interface

cliapisdk

SDK languages

GoTypeScript

Network & secrets

Egress controls

Yes

Secrets

Yes

Bring your own cloud

self-hosted (runs entirely on customer-owned hardware/cloud) — beyond BYOC; no vendor control plane

Placement & use

Jurisdiction

customer-controlled — data never leaves the customer's network

Advertised workloads

AI agent sandboxes / code executionCoding agents (Claude Code, Codex, OpenCode) in an isolated root VMK3s / HA Kubernetes clusters (dev, test, demos, autoscaling)Long lived dev environments / homelabsGPU inference & fine tuningRemote BuildKit / CICode review bots

03 Capabilities 17 pass · 4 partial · 12 fail · 54 of 61 assessed

Supported — Documented on the public surface and verified.
Partially supported — Exists with caveats: gated, thin, or enterprise-only.
Not supported — Checked and not offered.
Not assessed — Scanned before this capability was tracked. Not a lack.

Compute & storage 5/6

Persistent diskStorage that survives restart/stop (not ephemeral-only).

Supported

Object storageManaged S3-compatible / blob object store the platform PROVIDES to a user's workloads (buckets, presigned URLs). DISTINCT from persistent-disk (block/volume attached to an instance) and from a self-host dependency (source.self_host.deps[]=["object-storage"] is an infra dep to RUN an OSS tool — the opposite direction). SCOPE varies and matters: native first-class (Railway Buckets, Cloudflare R2) vs a sibling SKU / extension (Fly Tigris, Bunny Storage, DigitalOcean Spaces) — record which in the evidence quote / note. Admitted v15.

Not applicable

Snapshots / forkingSnapshot or copy-on-write fork of a running instance (filesystem-only counts). Whether the snapshot also restores memory + running processes is recorded separately by memory-snapshot (v19).

Supported

Live-state (memory) snapshotsA snapshot / checkpoint / pause captures a running instance's MEMORY and PROCESS state and restores it, so running processes continue where they left off instead of a freshly booted instance with the same files. Counts whether user-triggered (snapshot, checkpoint, pause-to-storage) or used to restore pre-initialised state (memory snapshots for fast cold starts). Distinct from snapshots-forks (any snapshot or fork, including filesystem-only; a product passing that key may still fail this one) and from scale-to-zero (an idle-cost property; suspension may or may not keep memory). Actor multiplexing (see scale-to-zero) records its live-state half here — only when the suspended actor's MEMORY/process state is what comes back, not a freshly booted worker with the actor's files.

Not assessed

Scale to zeroIdle instances suspend at no / negligible cost. ACTOR MULTIPLEXING (many suspended stateful actors sharing a small pool of pre-warmed workers, woken on request — Agent Substrate, AX, kagent; Rivet's hibernating actors) has NO key of its own (proposal REJECTED v20) — score the idle-cost half HERE and the live-state half under memory-snapshot; the oversubscription ratio / density is a performance characteristic the registry does not key.

Partially supported

GPU computeGPU-backed instances available.

Supported

Multi-regionCompute placeable in more than one geographic region.

Not applicable

Sandbox templates / custom imagesBuild reusable sandbox/VM images from an OCI image or Dockerfile (a base you fork instances from).

Supported

Cloud-init / ignition configCustomise a VM / microVM / instance at boot via cloud-init (or ignition) user-data — the same boot-metadata interface as AWS/Azure/GCP. Inject packages, users, SSH keys, files, and run-commands declaratively at launch. Distinct from sandbox-templates (a PREBUILT image you fork instances from) — this is PER-LAUNCH declarative customisation, not a baked image.

Supported

Desktop / computer-use sandboxA virtual desktop (GUI) for LLM computer-use — browser + desktop automation, often via noVNC/VNC.

Not applicable

Selectable isolation runtimeThe user chooses the isolation runtime per workload / environment / sandbox from more than one option (e.g. microVM vs gVisor vs plain container, native namespaces vs gVisor, gVisor vs VM). Records the CHOICE; the isolation_primitive facet still records the best-evidenced primary. A platform that switches runtime automatically without a user choice (e.g. gVisor forced for GPU) does not pass on that alone.

Not assessed

Networking & delivery 2/3

Automatic HTTPSTLS endpoints provisioned automatically per workload.

Not applicable

Built-in reverse proxyPlatform routes external traffic to workload services.

Partially supported

Custom domainsBring-your-own domain via CNAME/DNS.

Not applicable

Public preview URLsShareable per-deploy / per-branch URLs.

Not applicable

Direct public IPv6Per-instance stable public IPv6 for raw TCP/UDP (beyond a managed HTTPS proxy) — e.g. mosh / raw sockets.

Not applicable

Egress controlsConfigurable OUTBOUND network policy — egress firewall / allowlist / egress proxy on traffic LEAVING a workload. Scoped to OUTBOUND only (v15): private-network REACHABILITY between a user's own services is private-networking, not this. Static-egress-IP belongs here (an outbound concept).

Supported

Private networkingA platform-internal private network between a user's OWN services — service-to-service connectivity, VPC, service mesh, and/or service discovery, not exposed to the public internet. DISTINCT from egress-controls (OUTBOUND firewall/allowlist), reverse-proxy (PUBLIC inbound ingress), and direct-ipv6 (per-instance PUBLIC addressing). Admitted v15.

Supported

Email send / receiveSend and/or receive email from the workload.

Not applicable

Edge KV storeA globally-replicated key-value store read from WITHIN an edge runtime at the PoP (low-latency, eventually-consistent) — Cloudflare Workers KV, Deno KV, Fastly KV Store, Akamai EdgeKV, Vercel Edge Config. Distinct from first-party-db (a managed DATABASE service you provision and connect to) and from http-query-api (HTTP access to an external store) — edge-kv is colocated with the edge compute and read at the edge.

Not applicable

Developer access 6/7

Public APIDocumented programmatic API.

Supported

OpenAPI specMachine-readable OpenAPI / Swagger spec published.

Supported

CLIOfficial command-line tool.

Supported

SDKOfficial client library/libraries.

Supported

SSH accessDirect SSH into workloads.

Supported

Filesystem APIRemote file operations over the API (list/read/write/watch/copy/upload) without SSH.

Supported

Git deployDeploy from a Git repo / push-to-deploy.

Not applicable

Private container registryHosted private image registry.

Not supported

E2B-compatible APIDrop-in compatibility with the E2B sandbox API/SDKs — existing E2B client code runs against this product by changing the endpoint/domain + key, with no business-code changes. E2B itself passes as the reference implementation. Distinct from public-api / sdk (the product has its own API — this key says it also speaks another vendor's) and from self-host-oss (a self-hosted E2B-compatible server is scored on both).

Not assessed

HTTP data APIQuery / read / write the stored DATA over plain HTTP/REST (or GraphQL) WITHOUT the native protocol driver (Postgres wire / Redis RESP) — agent- and edge-friendly data access via fetch(). The DATA plane; distinct from public-api (a control-plane / management API). Auto-generated-from-schema REST/GraphQL (PostgREST, pg_graphql) is a flavour of this.

Not applicable

AI & agents 1/9

Built-in coding agentShips a first-party AI coding agent in the product.

Not supported

Agent skillsInstallable / declarable agent skills or tools.

Supported

AI app builderPrompt-to-app / vibe-coding generation surface.

Not applicable

MCP serverExposes a Model Context Protocol server for agents.

Not supported

MCP clientActs as an MCP client / consumes MCP tools.

Not supported

MCP-server hostingRun/host MCP servers as a workload on the platform (distinct from exposing a first-party MCP control server — that is mcp-server).

Not supported

LLM gatewayRoutes LLM API calls through the platform (multi-provider).

Not supported

BYOK for LLMsBring-your-own LLM provider keys.

Not supported

Model inference API (first-party)A FIRST-PARTY hosted LLM/model inference API — the provider serves its OWN catalogue of (usually open-weight) models behind a (typically OpenAI-compatible) endpoint, billed per token. Distinct from llm-gateway (a multi-PROVIDER proxy/router for YOUR calls to external providers like OpenAI/Anthropic) and from byok-llm (bring your own provider keys) — here the platform IS the inference provider, serving its own models.

Not supported

Autonomous QA agentA first-party AUTONOMOUS AI agent that QA-TESTS a running app / implementation — exercising it like a real user (clicking through flows, checking behaviour) and reporting bugs/defects (often back to a coding agent, or before a human review). Distinct from built-in-agent (a code-AUTHORING agent — this one VERIFIES the result, it does not write the feature; a product can ship both), from ai-guided-code-review (organises a diff for a HUMAN to review — not an autonomous tester), and from observability (runtime metrics/logs, not active testing).

Not supported

Credential-injection proxyThe platform holds real secrets OUTSIDE the workload and injects them on the wire (an egress / broker proxy swaps a placeholder or phantom token for the real credential on matching outbound requests), so code running in the sandbox — e.g. an untrusted agent — never sees or can exfiltrate the real key. Distinct from secrets-management (storage + injection INTO the workload as env vars/files — the workload holds the secret) and from egress-controls (outbound allow/deny POLICY; a product can have an allowlist without injecting credentials, and vice versa).

Not assessed

Preinstalled coding agentThe platform installs and launches a THIRD-PARTY coding agent (a harnesses.yml entry — Claude Code, Codex, OpenCode, Pi ...) inside a workspace/sandbox it provisions, with the agent's auth wired in (your own account or API key), so you start an agent session rather than an empty box. Distinct from built-in-agent (a FIRST-PARTY agent the vendor ships) and from harnesses[] (which records that a harness CAN target the product, not that the product runs it for you).

Not assessed

Data 0/0

First-party databasePlatform-provided managed database.

Not applicable

Database branchingCopy-on-write branch of a DATABASE (schema + data) as a dev-lifecycle primitive — branch your data like code, usually instant via a metadata operation. Distinct from snapshots-forks (forks a running compute INSTANCE / VM state) and from preview-environments (a full per-PR environment that may USE a DB branch). For a data product a CoW branch maps HERE, not to snapshots-forks.

Not applicable

Vector searchFirst-class storage, indexing, and similarity search of vector embeddings — a native vector type/index or a managed vector DB. The data-layer primitive for RAG / semantic retrieval.

Not applicable

Ephemeral instant DB (no-signup)Provision a working, usable instance via a single command / HTTP call with NO account, signup, or card — typically time-boxed (expires unless claimed). A zero-onboarding path an agent can hit directly.

Not applicable

Platform & operations 0/3

Scheduled tasksCron / scheduled job primitive.

Not supported

Durable workflowsDurable execution / long-running workflow primitive.

Not applicable

Preview environmentsA full EPHEMERAL environment spun up per PR / branch — compute + addons + (often) a DB branch — torn down on merge. More than preview-urls (which is just a shareable URL for one deploy).

Not applicable

Built-in observabilityFirst-party metrics / logs / tracing / APM / profiling included in the platform (no third-party stack required to see what a workload is doing).

Partially supported

Managed CI/CD runnersPlatform-hosted, drop-in CI/CD runner VMs (GitHub Actions / GitLab), typically faster and cheaper than the CI vendor's own hosted runners, billed per runner-minute; isolated + ephemeral per job. Distinct from git-deploy (push-to-deploy of an APP) and scheduled-tasks (cron) — this is managed CI COMPUTE you point your existing pipelines at.

Not supported

Project template marketplaceA marketplace / gallery of prebuilt PROJECT STARTER templates (apps or websites) a user clones or launches a new project from and then customises — the "start from a template" surface of a builder / PaaS. Distinct from sandbox-templates (a COMPUTE base IMAGE you fork runtime INSTANCES from — Dockerfile / OCI), from app-builder (the prompt-to-app GENERATION surface — a product can have both), and from one-click OSS-app catalogues / helm-addon-marketplace (deploy a FINISHED app as-is, not a starter you build on).

Not applicable

Organisation & security 3/5

Built-in authPlatform-provided authentication / IAM for workloads.

Not supported

SSO / SAMLEnterprise single sign-on.

Not applicable

Secrets managementFirst-class secrets storage / injection.

Supported

TeamsMulti-user team accounts.

Supported

SharingShare a running workload/resource via link (optionally gated).

Not applicable

BYOCRuns inside the customer's own cloud account.

Supported

Deploy into customers' VPCsA SaaS vendor uses the platform to deploy and operate ITS software inside ITS CUSTOMERS' cloud accounts / VPCs (nested or "customer BYOC"), managed from the vendor's control plane. Distinct from byoc (your own workloads in your own cloud account).

Not assessed

Workload identityThe platform gives each workload its own verifiable identity (OIDC token, SPIFFE SVID, cloud IAM federation) that it exchanges for short-lived credentials, so no long-lived static secret is stored or injected. Distinct from secrets-management (stores / injects static secrets) and credential-injection-proxy (swaps real secrets in on the wire).

Not assessed

Self-host / OSS coreOpen-source core that can be self-hosted.

Partially supported

Proposed, not verified

Capabilities the scan saw but the registry does not track yet. A key is admitted only once two distinct products exhibit it. These are not scored.

On-the-wire credential injection proxy (Bearer/Basic/OAuth stripped from the workload, injected on the host)credential-injection-proxy
“Register a Bearer, Basic, or OAuth credential once. The proxy injects it on matching requests and strips the workload's placeholder ... credentials stay on the host.” slicervm.com

04 Agent readiness Pre-login surface · counts, not a grade

Can an agent read it?

parse-ability · docs, metadata, machine-readable surfaces

7/11

6 full · 1 partial · 64% of applicable checks

llms.txt
Not supported
“No /llms.txt (apex Next.js returns the SPA shell); docs (mkdocs-material) serves no llms.txt.”
llms-full.txt
Not supported
“No /llms-full.txt.”
robots.txt AI policy
Partially supported
“robots.txt = 'User-Agent: * / Allow: /' — silent default-allow, no explicit AI-UA policy.”
JSON-LD
Not supported
“0 <script type=ld+json> on the homepage (rich OG meta present, but no JSON-LD).”
Sitemap
Supported
“sitemap.xml present, 22 URLs (marketing + blog); referenced in robots.txt.”
Meta tags
Supported
“Complete <title>, meta description, and full OpenGraph (og:title/description/image/url) — descriptive.”
Markdown negotiation
Not supported
“No markdown variant served on content negotiation (Next.js apex + mkdocs docs).”
Content efficiency
Supported
“Readable-text ÷ HTML = 9.2% (server-rendered, >5%).”
Docs discoverable
Supported
“'Documentation' is a first-class hero/nav link to docs.slicervm.com, reachable without JS.”
Machine-readable pricing
Supported
“Structured pricing page with three named tiers + explicit prices ($25 / $125 / $250).”
No anti-bot wall
Supported
“No challenge on public content — curl + firecrawl fetched landing, pricing, docs, OpenAPI, sitemap cleanly.”

Can an agent drive it?

act-ability · APIs, SDKs, MCP, credentials, webhooks

8/10

6 full · 2 partial · 80% of applicable checks

Public API
Supported
“Documented REST API (docs.slicervm.com/reference/api/) for managing micro-VMs, images, disks, operations.”
OpenAPI spec
Supported
“Fetchable, valid OpenAPI 3.0.3 spec at docs.slicervm.com/openapi.yaml (27 paths, ErrorResponse schema).”
MCP server
Not supported
“No MCP server (no /.well-known/mcp, no documented/npm MCP server).”
SDK packages
Supported
“Two official SDKs — Go + TypeScript.”
Auth documented
Supported
“Clear API-auth docs: enable daemon auth, token saved to /var/lib/slicer/auth/token, send 'Authorization: Bearer TOKEN'.”
Self-serve credentials
Partially supported
“Self-service purchase (14-day trial + card, no sales gate); the API token is then auto-generated on the self-hosted daemon (programmatic). Partial — a license purchase/human step precedes running the daemon.”
Webhooks
Not supported
“No documented webhooks.”
CLI tool
Supported
“Official `slicer` CLI.”
Error model
Supported
“OpenAPI defines an ErrorResponse schema (required `error`) returned across endpoints — a documented JSON error model.”
Rate limits documented
Not applicable
“Self-hosted single-tenant daemon — no vendor API rate limits apply; dropped from the denominator.”
Agent config files
Partially supported
“A published agent-skills repo (github.com/slicervm/agent-skills) is one agent-config surface; no agents.md or /.well-known/agent.”

05 Coding harnesses Which agents and IDEs are documented to run here

Advertised integrations 3

Claude Code Anthropic
Supported
“Run Claude, Codex, and OpenCode in its own VM with root access. Copy out the results when it's done.”
Source docs.slicervm.com
Codex CLI OpenAI
Supported
“Run Claude, Codex, and OpenCode in its own VM with root access.”
Source docs.slicervm.com
OpenCode opencode
Supported
“$ slicer vm exec vm-1 opencode -m "Review this code and quit when done" — OpenCode driven inside a Slicer microVM.”
Source slicervm.com

Plausible compatibility 12

Derived, not stored: the product passes SSH access, so any CLI coding agent is installable inside it. This is plausible compatibility, not a supported integration.

Aider
Amp
Antigravity
Devin
Droid
Gemini CLI
Goose
Hermes Agent
Kilo Code
Kiro CLI
Pi
Qwen Code

06 Compliance & regions Standards held, with ordinal rigor; never a score

Certifications held 0

No attestations found on the public surface. Empty means nothing is advertised, after checking, not that nothing was checked.

Regions —

Regions are not disclosed on the public surface.

SELF-HOSTED — there are NO vendor-operated regions. Placement is entirely the operator's choice: their Mac, Linux bare-metal (Hetzner, AWS Metal, PhoenixNAP, Vultr, Scaleway, OVHCloud, colo), mini PCs / Raspberry Pi, or a cloud VM with nested virt (GCE, Azure, OCI, DigitalOcean, AWS EC2). 'disclosed:false' reflects that region is not a product facet, not that it is hidden.

Legal

07 Company & presence Facts only, not scored

Company

Headquarters: Peterborough, England, UK
Founded: OpenFaaS Ltd incorporated 2017 (company #11076587); Slicer developed internally since 2022, publicly launched as a product in 2025.
Team size: Not disclosed
Hiring: Unknown

Notable people

Alex Ellis (founder, OpenFaaS Ltd; creator of OpenFaaS, inlets, Actuated; CNCF ambassador)

Activity

Last release: Actively developed — Slicer for Mac preview shipped Feb 2026; ongoing SDK releases in github.com/slicervm. slicervm.com
Last blog post: Active blog (2025–2026): recent posts incl. 'One tool for agents, clusters, and e2e tests' (Feb 19, 2026), 'Slicer for Mac: Preview' (Feb 11, 2026), 'Programmable microVM egress', 'Slicer 2025 wrap-up'. slicervm.com

Presence 4

Links found on the public surface scanned; not an exhaustive search.

08 Sources & method How this entry was produced

Public surface only

Everything here was read from slicervm.com's unauthenticated pages, docs, pricing and repository on 23 Jul 2026. Nothing behind a login was used.

Statuses, not scores

Capabilities are pass, partial or fail against a written rubric (features v17). “Not assessed” means the scan predates the key.

Confidence is separate

Each fact carries its own confidence. Low-confidence facts are shown, never hidden, so you can weigh them.

Schema: scan v5
Features registry: v17
Keys tracked today: 61
Assessed on this entry: 54

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