Limitations

This page is the honest list for 0.1. Prefer reading it over marketing claims.

Explicitly unsupported

  • Migrating arbitrary live call stacks / instruction pointers across runtimes (Continuum does not claim this)
  • Cross-runtime continuation resume (contract returns Unsupported; same-runtime explicit checkpoint is Experimental — see Continuum)
  • Deterministic replay engine (journal schema only)
  • Migrating functions / closures as callable values across runtimes
  • Migrating in-flight async tasks / promises / coroutines
  • WASM binding capture or restore / continuum
  • Non-string map keys round-tripping cleanly to JS objects
  • Shared object-identity graphs with cycles (bindings-first model; ref exists but restore is incomplete)
  • Hard multi-tenant isolation (no seccomp/Seatbelt/Windows job-object enforcement yet)
  • Mirror reverse sync for arbitrary nodes (gated; returns Unsupported unless ExactYes)
  • Mirror property-based equivalence as a complete fuzzer (plx verify --property is notes / confidence only — not proof)
  • Mirror watch daemon (plx watch) — not shipped
  • Treating all language pairs as equally mature (see pair tiers in Mirror and Connectors)
  • Scaffold connectors (Go, Java, Ruby, C#, …): identity + host probe only — execute/restore/migrate return Unsupported until a real worker/codegen ships

Semantic edge cases

CaseDefault behavior
Python int outside JS safe integer rangePromote to JS BigInt
Same, with --no-prefer-bigintReject (MigrationRejected / LOSSY)
Same, with --allow-lossy and no BigIntCoerce to Number (lossy)
Python tuple → JSBecomes Array (SAFE)
Python set → JSBecomes Array (SAFE)
bytes → JSUint8Array (SAFE)
Unknown host typesUnsupported PIR node

Host discovery quirks

  • Windows Store Python stubs are treated as unavailable
  • Discovery order: python, python3, py, then %LOCALAPPDATA%\Programs\Python\*\python.exe and Program Files trees
  • Node discovery: node, nodejs, then %ProgramFiles%\nodejs\node.exe

Stability

  • PIR schema, protocol, snapshot format, adapter interface, UES format, PCIR schema, PUIR schema, and Mirror link format are versioned independently (1 today unless noted)
  • Breaking changes will bump those constants; loaders reject mismatches
  • CLI flag surface may grow; prefer --json for scripting
  • See Versioning for which constant to bump