OpenChainGraph · Kernel VM

How the Kernel VM Works

Same JS. Three runtimes. One hash, or the run is rejected.

kernel-vm.html runs a kernel's compute(policy_parameters) twice: once inside a sandboxed QuickJS-ng WebAssembly VM, once natively in your browser tab, and shows whether the two execution_hash values agree. This page explains why that agreement is the whole point, and what a kernel is forbidden from doing to keep it.

The three runtimes, one source
One kernel source: compute(policy_parameters)
Runtime 1
Browser tab (native)
Runtime 2
QuickJS-ng WebAssembly VM
Runtime 3
risc0 zkVM guest
execution_hash agrees ✓
  1. A kernel is one compute(policy_parameters) function, deterministic by construction.
  2. It runs in your browser tab natively (no sandbox), the fast path, what a developer sees first.
  3. The identical source runs again inside a hermetic QuickJS-ng WebAssembly VM, sandboxed, zero network, zero fetch. This is what kernel-vm.html demonstrates live.
  4. The identical source proves a third time inside a risc0 zkVM guest, same bytes, same digest, and now a groth16 proof anyone can verify without re-running the code. See Proving It Ran for that runtime's own deep dive.
  5. All three emit execution_hash over the same canonical {policy_parameters, output_payload} preimage (RFC 8785/JCS). If any runtime disagrees, that disagreement is the finding, not something the page hides.
  6. The deterministic compute profile (below) explains why they agree: it names every door nondeterminism could sneak through and bans all of them at the kernel-authoring level.
Want to see it run? Open kernel-vm.html and pick a kernel from the dropdown. Step 1 runs runtimes 1 and 2 live in this browser, right now, with zero network calls.
The banned doors: ocg-deterministic-compute@2 (SPEC.md §24.1)

A conforming kernel MUST NOT let its output depend on any of these seven nondeterminism sources. Names and rules below are quoted verbatim from the normative spec; the gloss is a plain-English one-liner.

DoorSource (verbatim, SPEC.md §24.1)Plain English
D1**Non-finite floats** (`NaN`, `±Infinity`)No NaN or Infinity ever leaves compute() silently.
D2**Object / key iteration order**Object key order can never change the hash: one canonical sorter does it.
D3**Transcendental math** (`Math.exp/log/log2/sin/cos/pow`)No engine-native sin/cos/log/pow; every kernel ships its own portable math.
D4**Wall-clock time** (`Date.*`, timers)No reading the clock inside a kernel, ever.
D5**Randomness** (`Math.random`, CSPRNG)No dice rolls inside a kernel: Math.random and CSPRNG are both out.
D6**Locale / `Intl`**No locale-formatted numbers: one pinned formatter, or none at all.
D7**Environment / platform APIs**Anything environment-sensitive gets a fully specified deterministic stand-in.
Evidence
424gpu:false kernels, VM-verified
1069conformance vectors checked

Every gpu:false, non-private-input kernel's conformance fixtures run through the browser VM and diff byte-for-byte against the canonical worker hash on every push (chaingraph/kernels/vm-parity-gate.mjs). Both counts above are computed live from the kernel registry and its fixtures at generation time, never hardcoded.

Want a different kernel? All 424 kernels above are runnable via the catalog and the MCP server. Browse the full catalog on the ChainGraph catalog or call it over MCP at mcp.ainumbers.co. See also the decision boundary explorer, which sweeps a kernel's inputs using the same compute() step, and Proving It Ran, the third-runtime deep dive.