{"id":"kiln-ai-kilntainers","name":"Kilntainers","homepage":"https://kiln.tech","repo_url":"https://github.com/Kiln-AI/Kilntainers","category":"devtools","subcategories":[],"tags":["mcp","sandbox","containers","docker","podman","micro-vm","wasm","agent-tools","security","devtools"],"what_it_does":"Kilntainers is an MCP server that provides LLM agents isolated, ephemeral Linux-like execution sandboxes for running shell commands via a single MCP tool (sandbox_exec). It supports multiple backend runtimes including local OCI containers (Docker/Podman), cloud micro-VM sandboxes (Modal/E2B), and WebAssembly-based sandboxes (BusyBox/WASM).","use_cases":["Running shell commands safely on behalf of LLM agents with strong isolation","On-demand command execution for data processing (e.g., grep/awk/jq/find/sed workflows)","Parallel agent execution with separate ephemeral environments","Testing/automation where untrusted agent instructions must not access host OS"],"not_for":["Running agents that require persistent shared filesystem/state across sessions","Use as a general-purpose remote shell without strict command/output controls","Scenarios where you cannot secure or validate the agent’s command inputs (since it can run arbitrary shell commands inside the sandbox)"],"best_when":"You want a simple MCP tool interface for command execution while isolating the execution environment per agent/session and optionally scaling across local and cloud backends.","avoid_when":"You need strong governance over exactly what commands can be executed (e.g., allowlists/denylists not described here), or you require a standardized REST/HTTP API surface instead of MCP.","alternatives":["Running commands via a dedicated job runner with allowlisted commands (custom service)","Other sandboxed execution frameworks (e.g., containerized execution services with strict command policies)","Use remote execution tools integrated into your own infra with IAM and allowlists"],"af_score":52.2,"security_score":45.5,"reliability_score":22.5,"package_type":"mcp_server","discovery_source":["github"],"priority":"high","status":"evaluated","version_evaluated":null,"last_evaluated":"2026-03-30T15:26:26.969382+00:00","interface":{"has_rest_api":false,"has_graphql":false,"has_grpc":false,"has_mcp_server":true,"mcp_server_url":null,"has_sdk":false,"sdk_languages":[],"openapi_spec_url":null,"webhooks":false},"auth":{"methods":["stdio transport (no network auth described)","HTTP transport (no auth described)","Modal backend: modal setup / modal-token-id & modal-token-secret","E2B backend: E2B API key via flag or E2B_API_KEY env var"],"oauth":false,"scopes":false,"notes":"Authentication is backend-specific for cloud providers (Modal/E2B). For the MCP server itself, the README shows stdio wiring and HTTP bind/port options but does not document authentication or authorization for incoming MCP clients."},"pricing":{"model":null,"free_tier_exists":false,"free_tier_limits":null,"paid_tiers":[],"requires_credit_card":false,"estimated_workload_costs":null,"notes":"Local backends have no external metering beyond your infrastructure. Cloud backends (Modal/E2B) imply usage-based costs, but no pricing/tier details are provided in the supplied content."},"requirements":{"requires_signup":false,"requires_credit_card":false,"domain_verification":false,"data_residency":[],"compliance":[],"min_contract":null},"agent_readiness":{"af_score":52.2,"security_score":45.5,"reliability_score":22.5,"mcp_server_quality":88.0,"documentation_accuracy":75.0,"error_message_quality":0.0,"error_message_notes":null,"auth_complexity":35.0,"rate_limit_clarity":10.0,"tls_enforcement":40.0,"auth_strength":45.0,"scope_granularity":10.0,"dependency_hygiene":55.0,"secret_handling":80.0,"security_notes":"Security posture is primarily isolation-based: each MCP connection gets a dedicated ephemeral sandbox and the agent communicates with the sandbox over MCP rather than executing inside it, reducing host exposure and cross-contamination. However, the provided content does not document authentication/authorization for the MCP server (especially in HTTP mode), does not describe fine-grained command allowlisting, and does not specify how input is sanitized or how dangerous operations are constrained beyond backend isolation and time/output/network limits. Secret handling is implied as safe (no agent secrets exposed to the sandbox), but exact implementation details and guarantees are not provided.","uptime_documented":0.0,"version_stability":30.0,"breaking_changes_history":20.0,"error_recovery":40.0,"idempotency_support":"false","idempotency_notes":"Executes shell commands; whether operations are idempotent depends on the command semantics, and no idempotency mechanism is described.","pagination_style":"none","retry_guidance_documented":false,"known_agent_gotchas":["sandbox_exec runs arbitrary Linux commands (within the sandbox). Agents may still generate expensive workloads (CPU/memory/output) unless limits are enforced.","Network access is optional and defaults to disabled; enabling --network changes risk profile and allowed behaviors.","Output is capped (output-limit default ~2 MiB); larger commands may truncate or fail depending on implementation.","Long-running commands: default exec timeout (120s) and per-backend sandbox lifetime settings may terminate jobs unexpectedly if not accounted for."]}}