Status and limitations

Updated: October 14, 2026. The CLI identifies this development build as 0.3.0-dev. It is not a published stable release.

Available now

Variables, functions, closures, conditionals, loops, collections, and structured diagnostics.
Checked annotations, records, enums, optional values, and try/catch, including call stacks and static checking of known contracts.
Project manifests, isolated named tests, and locked local package snapshots through zy init, zy test, and zy add.
Exact signed 64-bit integer operations with overflow errors, floating division, and explicit div().
IPv4/CIDR literals, IPv4/IPv6 parsing, membership, set operations, bounded splitting, and variable-size allocation.
Overflow-safe ranges, call/parser limits, cycle-aware display, and cooperative cancellation.
File writes, JSON/environment/path APIs, bounded HTTP client requests, UTC time utilities, and cryptographic helpers.
CLI run/check commands, script arguments, help/version, and timeouts.
HTTP servers and MongoDB through zy serve, with isolated Zy handlers, bearer-key authentication, bounded requests, and health checks.
Backend services: prepared imports, users/sessions/roles, bounded queries and transactions, migrations, workers, cache, metrics, and tracing.
Local modules with explicit exports, private scopes, caching, cycle checks, and dependency diagnostics.
Lossless formatting with stdout, rewrite, and CI check modes.
VS Code preview, JSON diagnostic interchange, and language-server editor features.
Release tooling for six target archives, build metadata, checksums, and native smoke tests.
Three complete workflows with valid/invalid fixtures and deterministic reports.

Simulated or limited behavior

Feature	Actual implementation
`.ask()`	Prints a query and returns a simulated response string
`.detect_objects()`	Prints a message and returns `unknown_object`
`~`	Lowercases strings and counts substring matches for right-side words; threshold is `max(1, floor(word_count / 2))`
`quarantine()`	Prints a message and returns true; does not isolate an address
`trigger_alert()`	Prints a message; no service integration
Static checking	Checks known contracts; unannotated values and host results remain dynamic

Previously confirmed defects: fixed

Reproduction	Result now
`(0.0.0.0/0).split(1)`	Two `/1` blocks, then termination
`9007199254740993 + 0`	`9007199254740993`
`9007199254740993 > 9007199254740992`	`true`
`9223372036854775808`	Located syntax error
`(72 / 100) * 100`	`72.0`; use `div()` for integer division

Regression tests cover these and related boundaries. See the migration guide and numeric decision.

Remaining limitations

The language server supports contract diagnostics, formatting, typed signature hover, annotated record member completion, definition navigation, and document-local references/private-binding rename. It does not infer dynamic runtime types/members, resolve captured bindings assigned later, rename exported APIs, or search the whole workspace. A dot cursor can be repaired for completion; unrelated syntax errors can limit symbol results. Live AI integrations and public extension/release distribution remain unimplemented.

The formatter normalizes inline spacing and expands blocks/statements using exact lexemes, token preservation, and position-independent syntax checks. It preserves comments/literals and existing newlines. It does not wrap long calls, reorder declarations, or enforce a line width. Packages are local snapshots only. IPv6 uses string parsers rather than bare literals. Lists/maps have shallow contracts, enums have no payloads, and nullable flow narrowing is not implemented. Floats follow binary floating-point rounding and collection/record equality is by identity.

The expanded 15-job native CI run passed, including both architectures on Windows, Linux, and macOS, minimum-Go compatibility, Linux race detection, and real VS Code integration. All six cross-built archives also passed matching-host execution. Signing/notarization remains undecided.

Those hosted results refer to earlier snapshots. The 0.3.0-dev additions have local Go/vet, CLI/application, editor grammar/client, release-tool, and fuzz validation recorded in implementation progress.

Limits cover specific allocation paths and traversal depths, not total memory. Deadlines are cooperative and cannot forcibly interrupt host I/O. This is not a sandbox. An engineering visual/automation review is complete; three actual participant trials remain pending.

Validation

See implementation progress. Tests include boundary regressions, CLI/workflow integration, tutorial output fixtures, local documentation links, and runnable README/setup snippets.