Tinysandbox’s maintainer claims its WASM-based JavaScript runtime can run isolated code across browsers and serverless V8 environments with a roughly 1MiB baseline and 0.69MiB per isolate, potentially lowering the cost of agent and untrusted-code sandboxes.
state: expiredheat: lowuncertainty: highknownscott: mediumagent-sandboxing wasm untrusted-code-executionDan GoodmanTinysandbox
What is this?
Tinysandbox is presented as a WASM-based JavaScript runtime for isolated execution across browsers and serverless V8 environments, claiming about a 1 MiB baseline plus 0.69 MiB per isolate. The broader snippets establish that V8 isolates and JavaScript/WASM runtimes are used to run untrusted code with resource controls and portable, low-overhead serverless execution. However, none of the supplied result snippets directly verifies Tinysandbox’s measurements, security properties, portability claims, or Dan Goodman’s role, so those remain maintainer-attributed claims rather than independently established facts.
Why it matters to Scott
Scott already holds the core position in Sandboxed Execution and SiloOS: agent-generated code should run inside disposable, resource-bounded isolation. Tinysandbox adds a potentially relevant low-overhead WASM substrate that could affect sandbox density and Code-First Architecture economics, but its measurements and isolation guarantees remain unverified; the radar already tracks closely related JavaScript/WASM sandbox implementations, especially Sablejs 2.0.
ip:concept.sandboxed-executionip:framework.code-first-architecturedev:project.silo-osradar:sablejs-2-ai-code-sandboxradar:browserpod-codex-wasmradar:concept.agent-sandboxing
queries asked of Scott's wikis
- agent sandbox architecture and economics
- WASM versus containers for code isolation
- secure execution of agent-generated code
- portable runtimes across browser and serverless environments
- sandbox resource limits and isolation guarantees
- high-density ephemeral environments for coding agents
Measured heat
no measured readings yet — the hourly heat pass fills this in
How the heat travelled
no chain yet — the hourly chain pass fills this in
Evidence (2) — ⭐ canonical anchor
Interpretation history
2026-09-01T18:51:48Z
The release drew no implementation reports, independent benchmarks, or scrutiny during its observation window, leaving its portability, footprint, and isolation claims uncorroborated. It remains a benchmark candidate rather than an active developing signal.
2026-08-30T18:32:57Z
No new evidence or engagement has emerged to validate the claimed footprint, portability, or isolation guarantees. The case remains a potentially useful implementation to benchmark, but not yet an independently corroborated advance.
2026-08-30T18:31:24Z
grounded: known/medium — Scott already holds the core position in Sandboxed Execution and SiloOS: agent-generated code should run inside disposable, resource-bounded isolation. Tinysand
2026-08-30T18:28:26Z
case created — The first-party runtime makes specific portability and footprint claims relevant to lightweight isolated execution for agents.
Decision trace
- 09-02 04:51expireThe release drew no implementation reports, independent benchmarks, or scrutiny during its observation window, leaving its portability, footprint, and isolation claims uncorroborated. It remains a ben
- 09-02 04:51alert_silentThe only delta is negligible engagement after 48 hours, with no new technical evidence or consequential adoption; nothing warrants interrupting the normal briefing.
- 09-02 04:51alert_routeThe only delta is negligible engagement after 48 hours, with no new technical evidence or consequential adoption; nothing warrants interrupting the normal briefing.
- 08-31 04:32repriceNo new evidence or engagement has emerged to validate the claimed footprint, portability, or isolation guarantees. The case remains a potentially useful implementation to benchmark, but not yet an ind
- 08-31 04:32alert_silentThis is only an unchanged reobservation of the maintainer-attributed release; there is no consequential new delta that should interrupt the normal briefing cadence.
- 08-31 04:32alert_routeThis is only an unchanged reobservation of the maintainer-attributed release; there is no consequential new delta that should interrupt the normal briefing cadence.
- 08-31 04:31alert_silentThe maintainer-backed release is a concrete and relevant sandbox implementation, but it does not yet materially change Scott's architecture or require action today. Its portability, roughly 0.69
- 08-31 04:31surface_candidateThe maintainer-backed release is a concrete and relevant sandbox implementation, but it does not yet materially change Scott's architecture or require action today. Its portability, roughly 0.69
- 08-31 04:31alert_routeThe maintainer-backed release is a concrete and relevant sandbox implementation, but it does not yet materially change Scott's architecture or require action today. Its portability, roughly 0.69
- 08-31 04:31groundScott already holds the core position in Sandboxed Execution and SiloOS: agent-generated code should run inside disposable, resource-bounded isolation. Tinysandbox adds a potentially relevant low-over
- 08-31 04:28createThe first-party runtime makes specific portability and footprint claims relevant to lightweight isolated execution for agents.