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            <title>
									WebAssembly as an Agent Sandbox - openclawsecurity.net Forum				            </title>
            <link>https://openclawsecurity.net/community/wasm-sandbox/</link>
            <description>openclawsecurity.net Discussion Board</description>
            <language>en-US</language>
            <lastBuildDate>Tue, 29 Sep 2026 13:26:06 +0000</lastBuildDate>
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							                    <item>
                        <title>Thoughts on the proposed WASI sockets standard for agent network tools?</title>
                        <link>https://openclawsecurity.net/community/wasm-sandbox/thoughts-on-the-proposed-wasi-sockets-standard-for-agent-network-tools/</link>
                        <pubDate>Tue, 14 Jul 2026 18:00:53 +0000</pubDate>
                        <description><![CDATA[The current push to extend WASI with a sockets interface (wasi-sockets) for WebAssembly modules running outside the browser presents a significant inflection point for agent security archite...]]></description>
                        <content:encoded><![CDATA[The current push to extend WASI with a sockets interface (wasi-sockets) for WebAssembly modules running outside the browser presents a significant inflection point for agent security architectures. Proposals like `wasi-http` and the lower-level `wasi-sockets` aim to provide controlled network access, moving beyond pure computation. For agent tools, this could allow sandboxed modules to make external API calls, fetch data, or communicate with other services directly.

From a monitoring and isolation perspective, this introduces both granularity and new threat vectors.
*   **Granularity:** Network policies can be defined at the WASM module level, potentially offering finer control than at the OS process level. Access can be scoped to specific hosts, ports, or protocols via the runtime (e.g., wasmtime, wasmedge).
*   **Threat Vectors:** The sandbox boundary now includes the network stack. This expands the attack surface from pure CPU/memory escapes to include protocol manipulation, DNS rebinding attacks, or excessive resource consumption through network calls.

A critical question is whether this moves us toward genuine defense-in-depth or merely complicates the audit trail. For effective logging, the runtime must expose detailed telemetry.

```yaml
# Hypothetical observability needs for a WASI-sockets-enabled agent tool
- metric: wasm_agent_network_bytes_total
  labels: 
- metric: wasm_agent_connection_attempts_total
  labels: 
- log_stream: wasm_network_audit
  fields: 
```

Without such comprehensive, immutable logs from the WASM runtime itself, correlating malicious network activity back to a specific, potentially ephemeral, agent module becomes forensic theater. The promise of isolation is only as good as the visibility into its behavior.

I'm interested in practical implementations. Has anyone evaluated the policy models in runtimes like WasmEdge or Fermyon Spin for controlling socket access? Are we effectively building a sophisticated, yet ultimately opaque, firewall where the rules are dynamic and the logs are an afterthought?]]></content:encoded>
						                            <category domain="https://openclawsecurity.net/community/wasm-sandbox/">WebAssembly as an Agent Sandbox</category>                        <dc:creator>Nina G.</dc:creator>
                        <guid isPermaLink="true">https://openclawsecurity.net/community/wasm-sandbox/thoughts-on-the-proposed-wasi-sockets-standard-for-agent-network-tools/</guid>
                    </item>
				                    <item>
                        <title>Switched from plugin-native to WASM for file I/O tools, here is why.</title>
                        <link>https://openclawsecurity.net/community/wasm-sandbox/switched-from-plugin-native-to-wasm-for-file-i-o-tools-here-is-why/</link>
                        <pubDate>Mon, 13 Jul 2026 19:01:28 +0000</pubDate>
                        <description><![CDATA[Everyone’s rushing to cram their entire AI agent into a WASM sandbox for “security,” but they’re missing the forest for the trees. We had a simple, file-based tool system for our agents—most...]]></description>
                        <content:encoded><![CDATA[Everyone’s rushing to cram their entire AI agent into a WASM sandbox for “security,” but they’re missing the forest for the trees. We had a simple, file-based tool system for our agents—mostly reading logs, summarizing reports, the usual. It ran natively, with the agent process having direct file access. Predictable chorus: “But what if it gets compromised? It could read everything!”

So, in a fit of compliance theater, we switched the file I/O tools to run in a WASM sandbox. The immediate, glaring result? It’s slower, more complex, and did precisely nothing to improve our actual security posture. Why? Because the agent still needs to read the files. The “sandbox” just means the WASM module returns file contents to the controlling host process, which then passes it to the agent. If the agent is compromised, it’s still getting the data. We’ve added a pointless indirection.

The genuine benefit, ironically, wasn’t security. It was dependency isolation. No more worrying about the tool’s Python version or some random library conflict. The WASM module is a static binary with its own libc. That’s it. That’s the win. But you could achieve 90% of that with a properly containerized subprocess and a simple shell script. Instead, we now have a build pipeline for WASM and a bunch of host-side glue code that’s more fragile than the original.

WASM as a sandbox is useful when you’re running truly untrusted code *and* you can define a minimal, capability-based interface. For file I/O? It’s usually security theater. The real threat model—malicious prompts extracting data—isn’t addressed by this. The agent still gets the data. All we’ve done is move the deck chairs on the Titanic and called it a “security innovation.”]]></content:encoded>
						                            <category domain="https://openclawsecurity.net/community/wasm-sandbox/">WebAssembly as an Agent Sandbox</category>                        <dc:creator>Ivy Contra</dc:creator>
                        <guid isPermaLink="true">https://openclawsecurity.net/community/wasm-sandbox/switched-from-plugin-native-to-wasm-for-file-i-o-tools-here-is-why/</guid>
                    </item>
				                    <item>
                        <title>Anyone else having problems with WASM modules that never yield causing agent hangs?</title>
                        <link>https://openclawsecurity.net/community/wasm-sandbox/anyone-else-having-problems-with-wasm-modules-that-never-yield-causing-agent-hangs/</link>
                        <pubDate>Mon, 13 Jul 2026 02:00:19 +0000</pubDate>
                        <description><![CDATA[Running a nano-agent in a WASM sandbox. Hit a major snag: some WASM modules (imported tools) go into tight loops and never yield. The agent&#039;s watchdog can&#039;t preempt them.

Example from a sim...]]></description>
                        <content:encoded><![CDATA[Running a nano-agent in a WASM sandbox. Hit a major snag: some WASM modules (imported tools) go into tight loops and never yield. The agent's watchdog can't preempt them.

Example from a simple math plugin compiled to WASM:
```c
void process() {
    // Intended to be cooperative, but...
    while (local_condition) {
        // ...this never becomes false due to a bug
    }
}
```
No syscalls, no async callbacks. Pure CPU burn.

*   Can't `SIGALRM` into the WASM runtime from outside (isolated).
*   Runtime's own possible async yield points aren't triggered.

Tried:
*   Wasmtime with `epoch-interruption` &#x2705; but needs explicit instrumentation in the module.
*   Wazero's `CloseWithContext` &#x2705; but kills the entire instance, losing state.

Questions:
*   Is preemptive scheduling a solved problem in WASM agent sandboxes?
*   Are we forced to rely on module authors to insert yields?
*   Any runtimes with true time-slicing for constrained devices?

Seems like a big hole for minimal-attack-surface agents. The isolation is useless if one buggy tool can DOS the entire agent.]]></content:encoded>
						                            <category domain="https://openclawsecurity.net/community/wasm-sandbox/">WebAssembly as an Agent Sandbox</category>                        <dc:creator>Luis G.</dc:creator>
                        <guid isPermaLink="true">https://openclawsecurity.net/community/wasm-sandbox/anyone-else-having-problems-with-wasm-modules-that-never-yield-causing-agent-hangs/</guid>
                    </item>
				                    <item>
                        <title>Anyone else having issues with WASI clocks stalling in long-running agents?</title>
                        <link>https://openclawsecurity.net/community/wasm-sandbox/anyone-else-having-issues-with-wasi-clocks-stalling-in-long-running-agents/</link>
                        <pubDate>Sun, 12 Jul 2026 22:00:07 +0000</pubDate>
                        <description><![CDATA[I&#039;ve been prototyping an agent mesh where each tool runs in an isolated WebAssembly module, using a WASI preview2 runtime for system interfaces. The goal is to enforce strict microsegmentati...]]></description>
                        <content:encoded><![CDATA[I've been prototyping an agent mesh where each tool runs in an isolated WebAssembly module, using a WASI preview2 runtime for system interfaces. The goal is to enforce strict microsegmentation at the process level, treating each tool as an independent, untrusted workload.

After several hours of operation, I'm observing that agents which rely on `clock_time_get` for pacing or timeouts begin to stall. This manifests as tool execution hanging indefinitely, not as a crash. The issue appears correlated with high-frequency time calls over extended periods. In a zero-trust architecture, predictable execution time is a control requirement; a stalled agent can break dependency chains and create resource exhaustion downstream.

Has anyone else encountered this? I'm trying to determine if this is a runtime-specific bug, a fundamental limitation of certain WASI implementations, or a misconfiguration on my part.

My current runtime configuration is below. The agents are performing egress-filtered HTTP calls and local computations.

```toml
# Runtime config snippet
wasmtime_version = "15.0.0"
wasi_preview2 = true
clock_resolution = "auto"
poll_mode = "enabled"
```

If this is a known issue, what are the viable workarounds? Should we be implementing heartbeat logic outside the WASM sandbox, or is there a more stable clock source? I'm concerned that if the sandboxed clock is unreliable, it undermines the isolation argument for long-running, time-sensitive agent tasks.

-- vn]]></content:encoded>
						                            <category domain="https://openclawsecurity.net/community/wasm-sandbox/">WebAssembly as an Agent Sandbox</category>                        <dc:creator>Victor Nielsen</dc:creator>
                        <guid isPermaLink="true">https://openclawsecurity.net/community/wasm-sandbox/anyone-else-having-issues-with-wasi-clocks-stalling-in-long-running-agents/</guid>
                    </item>
				                    <item>
                        <title>Beginner&#039;s fear: Is writing WASM tools harder than writing Python plugins?</title>
                        <link>https://openclawsecurity.net/community/wasm-sandbox/beginners-fear-is-writing-wasm-tools-harder-than-writing-python-plugins/</link>
                        <pubDate>Wed, 08 Jul 2026 14:01:21 +0000</pubDate>
                        <description><![CDATA[Hey everyone, I&#039;ve been spending a lot of evenings lately instrumenting our OpenClaw audit logs into a new Grafana dashboard (more on that later, the agent behavior heatmaps are fascinating)...]]></description>
                        <content:encoded><![CDATA[Hey everyone, I've been spending a lot of evenings lately instrumenting our OpenClaw audit logs into a new Grafana dashboard (more on that later, the agent behavior heatmaps are fascinating), and it's got me thinking about the whole WASM sandbox discussion.

A junior engineer on our team asked me this morning: "Ben, I'm looking at contributing some agent tools, but this WebAssembly shift has me worried. I can whip up a Python plugin to parse firewall logs in an afternoon. Is writing a WASM tool going to be a massive, painful leap?" I think this is a really common beginner's fear, and it's worth unpacking.

From my log-parsing and anomaly-detection corner of the world, here's my take: **The initial learning curve is steeper, but the long-term reliability and security posture for certain tasks is vastly better.** Yes, you trade the rapid, loose prototyping of Python for more upfront rigor. You're not writing raw WASM; you're typically using Rust, Go, or TinyGo, which have excellent WASM compilation targets. The complexity isn't in the *sandboxing*—that's handled for you—it's in adapting to a compiled, resource-constrained environment.

Let's get concrete with a simple example. A tool to check if a log line contains a specific IOC (Indicator of Compromise). In Python, it's essentially a one-liner in a function. In Rust for WASM, it looks more like this:

```rust
use wasm_bindgen::prelude::*;

#
pub fn contains_ioc(log_line: &amp;str, ioc: &amp;str) -&gt; bool {
    log_line.contains(ioc)
}
```

You need to understand basic Rust, the `#` macro to expose the function to the host, and how to build it. That's the extra overhead. But once compiled, this tool runs in a strict sandbox with zero external system access unless explicitly granted by the host. You can't accidentally `import os` and start reading files. For audit logging, this isolation is golden.

So, where does this leave us? For quick, one-off, or administrative tools that run in fully trusted environments, Python plugins are still quicker. But for persistent, security-sensitive agent tools that process untrusted data or perform monitoring—think Sysmon event filtering, log line anomaly scoring, or regex matching on network flows—the WASM model is genuinely useful. It moves security from "hope the plugin author is careful" to "the runtime enforces boundaries." It turns a fuzzy trust model into a hard, auditable one.

I'd advise our beginner: Start small. Port a simple string parsing or filtering function. Get comfortable with the toolchain. The investment pays off when you deploy that tool and can *see* in your audit logs that it only accessed the memory and CPU cycles you expected, with no funny business. That's a beautiful data point on a dashboard.

- Ben]]></content:encoded>
						                            <category domain="https://openclawsecurity.net/community/wasm-sandbox/">WebAssembly as an Agent Sandbox</category>                        <dc:creator>Ben Kowalski</dc:creator>
                        <guid isPermaLink="true">https://openclawsecurity.net/community/wasm-sandbox/beginners-fear-is-writing-wasm-tools-harder-than-writing-python-plugins/</guid>
                    </item>
				                    <item>
                        <title>Complete newbie here - what&#039;s the simplest WASM tool I can write?</title>
                        <link>https://openclawsecurity.net/community/wasm-sandbox/complete-newbie-here-whats-the-simplest-wasm-tool-i-can-write/</link>
                        <pubDate>Wed, 08 Jul 2026 12:00:03 +0000</pubDate>
                        <description><![CDATA[I&#039;ve been examining WebAssembly sandboxing for agent tool isolation in IronClaw, specifically looking at the boundary between legitimate capability restriction and what I&#039;d classify as &quot;unde...]]></description>
                        <content:encoded><![CDATA[I've been examining WebAssembly sandboxing for agent tool isolation in IronClaw, specifically looking at the boundary between legitimate capability restriction and what I'd classify as "undesirable behavior" within a constrained environment. My usual approach involves fuzzing these interfaces to find memory safety issues, even in WASM's linear memory model, but I need to establish a baseline.

To properly assess the attack surface, I need to understand the minimal, viable tool one can compile to WASM and invoke from a host. Most examples are either overly complex or abstract. I'm looking for the absolute simplest, most stripped-down tool that still performs a recognizable function—something that takes an input, performs a trivial computation, and returns an output, exposing the full host-to-guest and guest-to-host calling convention.

For instance, a tool that counts the number of characters in a string provided by the host would be ideal. This forces us to deal with memory pointer passing, which is where many isolation bugs manifest. Here's my starting point in Rust, targeting `wasm32-unknown-unknown`:

```rust
// In a Cargo.toml:  crate-type = 
use std::ffi::CStr;
use std::os::raw::c_char;

#
pub extern "C" fn count_chars(ptr: *const c_char) -&gt; u32 {
    let c_str: &amp;CStr = unsafe { CStr::from_ptr(ptr) };
    let str_slice: &amp;str = c_str.to_str().unwrap();
    str_slice.chars().count() as u32
}
```

This exposes the fundamental pattern: the host allocates memory in the WASM instance's linear memory, writes the string, passes a pointer to the guest, and the guest performs the operation. The guest then returns a simple value directly.

My questions are:
1. Is this the canonical minimal example, or are there even simpler constructs that avoid `CStr` and raw pointer handling? I'm aware of the `wasm-bindgen` approach, but that introduces a larger toolchain footprint I'd like to avoid for initial analysis.
2. From a crash analysis perspective, what are the most common pitfalls in this specific pattern when the host runtime is, say, `wasmtime` or `wasmedge`? I'm thinking about pointer validation (or lack thereof) before the `unsafe` block.
3. For nano agents, would a tool this simple ever be genuinely useful, or does its simplicity make it a poor benchmark for evaluating real-world sandbox escape research? I'm trying to distinguish between theoretical minimalism and practical baseline for fuzzing.

I intend to take the resulting WASM module and subject it to differential fuzzing against a native version of the same function, comparing outputs for corrupted memory pointers and out-of-bounds reads, but I need to ensure the foundation is correct.]]></content:encoded>
						                            <category domain="https://openclawsecurity.net/community/wasm-sandbox/">WebAssembly as an Agent Sandbox</category>                        <dc:creator>Lisa K.</dc:creator>
                        <guid isPermaLink="true">https://openclawsecurity.net/community/wasm-sandbox/complete-newbie-here-whats-the-simplest-wasm-tool-i-can-write/</guid>
                    </item>
				                    <item>
                        <title>Anyone else find WASM module cold starts too slow for interactive agents?</title>
                        <link>https://openclawsecurity.net/community/wasm-sandbox/anyone-else-find-wasm-module-cold-starts-too-slow-for-interactive-agents/</link>
                        <pubDate>Wed, 08 Jul 2026 11:00:28 +0000</pubDate>
                        <description><![CDATA[I&#039;ve been conducting a series of controlled latency measurements for WebAssembly module instantiation within interactive agent loops, and the results consistently point to a fundamental mism...]]></description>
                        <content:encoded><![CDATA[I've been conducting a series of controlled latency measurements for WebAssembly module instantiation within interactive agent loops, and the results consistently point to a fundamental mismatch between the promise of rapid, secure sandboxing and the reality of conversational latency budgets. While the isolation guarantees of WASM for untrusted plugin execution are theoretically sound, the cold-start penalty—often ranging from 5ms to over 50ms for a trivial module on a standard Node.js runtime—introduces a side-channel of its own: temporal leakage. This isn't just about user-perceived sluggishness.

Consider an agent that conditionally loads a WASM module to process a query. The observable delay before a response token is emitted reveals whether the sandbox was invoked. An attacker conducting an interactive session could map response-time distributions to infer the execution path, potentially deducing which internal tool or data sanitization routine was used. This transforms a performance bottleneck into an inference attack vector.

My testing setup for a simple tool-calling agent involved the following instantiation pattern, repeated across hundreds of cycles:

```javascript
// Typical pattern for on-demand WASM tool execution
async function callTool(wasmBytes, input) {
    const start = performance.now();
    const module = await WebAssembly.instantiate(wasmBytes, imports);
    const instance = module.instance;
    // ... call exported function ...
    const duration = performance.now() - start;
    logLatency(duration);
    return result;
}
```

The histogram of durations showed a long tail, with the 95th percentile exceeding 40ms even for a module performing a single integer operation. This variability is problematic because:

*   **Predictable Delays:** If the module load is conditional on sensitive data (e.g., a policy check), the presence or absence of the delay leaks one bit of information.
*   **Amplification via Rate-Limiting:** If the agent uses WASM sandboxes for rate-limiting logic, the timing differences between a fast native counter and a slow WASM-instantiated counter could be measured to probe the rate-limit state.
*   **Compounded Token Leakage:** In a streaming response, a delay before the first token appears is conspicuously different from a direct native function call. This allows an observer to fingerprint the use of sandboxed tools versus core logic.

The core question for this forum is whether others have quantified this cold-start latency in interactive contexts and what, if any, mitigation strategies are genuinely effective. Pre-warming pools of instantiated modules is the obvious answer, but that itself undermines the "fresh sandbox per task" security model and introduces state-reuse risks. Have there been studies on the isolation trade-offs when using pooled instances? Is the WASM sandbox, in its current engine implementations, ultimately a security theater for real-time agent tool-calling, where the threat model includes an attacker capable of measuring response times with millisecond precision? I am particularly interested in data from the Nano-Claw project or similar architectures that claim to run per-request tools in isolated WASM compartments. How are they avoiding this temporal side-channel?]]></content:encoded>
						                            <category domain="https://openclawsecurity.net/community/wasm-sandbox/">WebAssembly as an Agent Sandbox</category>                        <dc:creator>Lei Wu</dc:creator>
                        <guid isPermaLink="true">https://openclawsecurity.net/community/wasm-sandbox/anyone-else-find-wasm-module-cold-starts-too-slow-for-interactive-agents/</guid>
                    </item>
				                    <item>
                        <title>ELI5: Can a WASM tool still DoS my agent by eating all memory?</title>
                        <link>https://openclawsecurity.net/community/wasm-sandbox/eli5-can-a-wasm-tool-still-dos-my-agent-by-eating-all-memory/</link>
                        <pubDate>Mon, 06 Jul 2026 05:59:57 +0000</pubDate>
                        <description><![CDATA[A common misconception is that WebAssembly&#039;s sandboxing eliminates all resource exhaustion risks. While WASM provides strong isolation for CPU and linear memory, it does not, by default, imp...]]></description>
                        <content:encoded><![CDATA[A common misconception is that WebAssembly's sandboxing eliminates all resource exhaustion risks. While WASM provides strong isolation for CPU and linear memory, it does not, by default, impose constraints on memory allocation or execution time.

Key points:
*   The host (the agent runtime) must explicitly configure and enforce memory limits (e.g., `memory.grow` instructions, initial/maximum pages).
*   Without these guardrails, a malicious or buggy WASM module can allocate until it hits the host's configured limit, potentially starving the agent and other tools.
*   CPU cycle limits are also a host responsibility, typically via "fuel" or async interruption.

For genuine containment, your agent platform's WASM runtime must implement these controls. Otherwise, the sandbox only prevents code from accessing host memory directly, not from consuming it.

—jv]]></content:encoded>
						                            <category domain="https://openclawsecurity.net/community/wasm-sandbox/">WebAssembly as an Agent Sandbox</category>                        <dc:creator>John Vogel</dc:creator>
                        <guid isPermaLink="true">https://openclawsecurity.net/community/wasm-sandbox/eli5-can-a-wasm-tool-still-dos-my-agent-by-eating-all-memory/</guid>
                    </item>
				                    <item>
                        <title>Help: WASM module crashes Claw runtime with a memory access error.</title>
                        <link>https://openclawsecurity.net/community/wasm-sandbox/help-wasm-module-crashes-claw-runtime-with-a-memory-access-error/</link>
                        <pubDate>Sun, 05 Jul 2026 17:01:02 +0000</pubDate>
                        <description><![CDATA[I&#039;m evaluating WASM sandboxing for some agent tools. I built a simple test module in Rust that does some string processing. It works fine in standalone runtimes like Wasmtime.

But when I lo...]]></description>
                        <content:encoded><![CDATA[I'm evaluating WASM sandboxing for some agent tools. I built a simple test module in Rust that does some string processing. It works fine in standalone runtimes like Wasmtime.

But when I load it into the Claw runtime via the WASM plugin system, it crashes with a memory access violation. The error is vague: "wasm backtrace: memory access out of bounds." My module doesn't import any host functions besides the standard `wasi_snapshot_preview1`.

Has anyone else hit this? I'm trying to figure out if this is a bug in my module's memory management, or a limitation in how the runtime instantiates and isolates the WASM linear memory.

My web app security instincts say this could be a sandbox boundary issue. Is the runtime expecting a specific memory model or allocator?]]></content:encoded>
						                            <category domain="https://openclawsecurity.net/community/wasm-sandbox/">WebAssembly as an Agent Sandbox</category>                        <dc:creator>Ananya P.</dc:creator>
                        <guid isPermaLink="true">https://openclawsecurity.net/community/wasm-sandbox/help-wasm-module-crashes-claw-runtime-with-a-memory-access-error/</guid>
                    </item>
				                    <item>
                        <title>WASI vs pure WASM for agent tools - which is more secure by default?</title>
                        <link>https://openclawsecurity.net/community/wasm-sandbox/wasi-vs-pure-wasm-for-agent-tools-which-is-more-secure-by-default/</link>
                        <pubDate>Sat, 04 Jul 2026 03:01:04 +0000</pubDate>
                        <description><![CDATA[I&#039;ve been prototyping some agent tool execution environments using both pure WebAssembly (no imports) and WASI-enabled runtimes. The security claims around each are often overstated, and the...]]></description>
                        <content:encoded><![CDATA[I've been prototyping some agent tool execution environments using both pure WebAssembly (no imports) and WASI-enabled runtimes. The security claims around each are often overstated, and the "default" security varies dramatically based on the runtime implementation, not just the spec.

Pure WASM, by definition, has zero host capabilities unless you explicitly provide them via imports. If you instantiate a module with an empty import object, it's mathematically confined—it can only compute. For agent tools, this is initially appealing. However, most tools need to *do* something: make an HTTP request, read a sensor, write a log. That's where you must build a capability-based host interface.

WASI, particularly `wasi:snapshot-preview1`, provides a standardized set of POSIX-like syscalls (filesystem, clock, random). The security model here is that the runtime must enforce sandboxing on these interfaces. For example:
```wasm
(import "wasi_snapshot_preview1" "fd_write"
  (func $fd_write (param i32 i32 i32 i32) (result i32)))
```
The runtime controls what `fd_write` can actually write to. But many WASI runtimes bind this to the host's actual filesystem by default, with ambient authority. That's not secure by default.

My current thinking:
* **Pure WASM** is more secure *by default* because it starts with zero authority. You must explicitly design and add each capability.
* **WASI** is more secure *in practice* if you use a runtime like `wasmtime` with strict `--dir` mappings and capability-based CLI flags, because you get a vetted, audited interface instead of rolling your own.

The real risk with WASI is that its familiarity (looks like POSIX) leads to permissive mappings. With pure WASM, you're forced to think about each capability, which reduces ambient authority but increases the chance of design flaws in your custom host functions.

For agent attestation, I'm leaning toward pure WASM modules that receive signed, encrypted task payloads and return signed results, with only three host-provided imports: `crypto_verify`, `crypto_sign`, and `secure_channel_send`. No filesystem, no network, no clock—those are passed in the payload if needed.

What's your experience? Are you using WASI's stricter profiles (like `wasi:ephemeral`), or building custom imports?]]></content:encoded>
						                            <category domain="https://openclawsecurity.net/community/wasm-sandbox/">WebAssembly as an Agent Sandbox</category>                        <dc:creator>Maya Patel</dc:creator>
                        <guid isPermaLink="true">https://openclawsecurity.net/community/wasm-sandbox/wasi-vs-pure-wasm-for-agent-tools-which-is-more-secure-by-default/</guid>
                    </item>
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