Summary

The package currently exposes the wasi_snapshot_preview1 namespace across all runtimes, but the native/web backends still implement only a minimal command-style + virtual filesystem subset.

This issue is the execution-ordered tracker for closing the remaining Preview1 support gaps. Each checklist item below is backed by a child issue. Behavioral coverage belongs to each capability issue; the verification-phase items are complementary smoke, end-to-end, and documentation work.

Current state:

• Official WASI Preview1 surface: 46 functions
• Native/web backends: 19 implemented, 27 exported as explicit ENOSYS stubs
• Node backend: delegates to node:wasi, so its surface is not the limiting factor for wasd itself

Official references:

• Full Preview1 docs: https://github.com/WebAssembly/WASI/blob/wasi-0.1/preview1/docs.md#L1282
• Full Preview1 WITX: https://github.com/WebAssembly/WASI/blob/wasi-0.1/preview1/witx/wasi_snapshot_preview1.witx#L8

Execution Order

Phase 1: Low-Complexity Wins

• Implement clock_res_get for WASI Preview1 on native and web backends #18 Implement clock_res_get for WASI Preview1 on native and web backends. Refs: https://github.com/WebAssembly/WASI/blob/wasi-0.1/preview1/docs.md#L1399
• Use cryptographically secure randomness for WASI Preview1 random_get on native and web #19 Use cryptographically secure randomness for WASI Preview1 random_get on native and web. Refs: https://github.com/WebAssembly/WASI/blob/wasi-0.1/preview1/docs.md#L2421
• Provide configurable stdin input for WASI Preview1 native and web backends #20 Provide configurable stdin input for WASI Preview1 native and web backends. Refs: https://github.com/WebAssembly/WASI/blob/wasi-0.1/preview1/docs.md#L1818
• Implement fd_tell for WASI Preview1 on native and web backends #16 Implement fd_tell for WASI Preview1 on native and web backends. Refs: https://github.com/WebAssembly/WASI/blob/wasi-0.1/preview1/docs.md#L1964 , https://github.com/WebAssembly/WASI/blob/wasi-0.1/preview1/witx/wasi_snapshot_preview1.witx#L283

Phase 2: File Descriptor Model

• Support writable virtual files and non-stdio fd_write in WASI Preview1 #21 Support writable virtual files and non-stdio fd_write in WASI Preview1. Refs: https://github.com/WebAssembly/WASI/blob/wasi-0.1/preview1/docs.md#L1987
• Expand fd_fdstat_get and fd_filestat_get metadata to better match WASI Preview1 #22 Expand fd_fdstat_get and fd_filestat_get metadata to better match WASI Preview1. Refs: https://github.com/WebAssembly/WASI/blob/wasi-0.1/preview1/docs.md#L1555 , https://github.com/WebAssembly/WASI/blob/wasi-0.1/preview1/docs.md#L1630
• Implement fd_fdstat_set_flags for WASI Preview1 on native and web backends #23 Implement fd_fdstat_set_flags for WASI Preview1 on native and web backends. Refs: https://github.com/WebAssembly/WASI/blob/wasi-0.1/preview1/docs.md#L1578 Blocked by: Expand fd_fdstat_get and fd_filestat_get metadata to better match WASI Preview1 #22
• Implement fd_fdstat_set_rights for WASI Preview1 on native and web backends #24 Implement fd_fdstat_set_rights for WASI Preview1 on native and web backends. Refs: https://github.com/WebAssembly/WASI/blob/wasi-0.1/preview1/docs.md#L1603 Blocked by: Expand fd_fdstat_get and fd_filestat_get metadata to better match WASI Preview1 #22
• Implement fd_pread for WASI Preview1 on native and web backends #25 Implement fd_pread for WASI Preview1 on native and web backends. Refs: https://github.com/WebAssembly/WASI/blob/wasi-0.1/preview1/docs.md#L1708 Blocked by: Implement fd_tell for WASI Preview1 on native and web backends #16
• Implement fd_pwrite for WASI Preview1 on native and web backends #26 Implement fd_pwrite for WASI Preview1 on native and web backends. Refs: https://github.com/WebAssembly/WASI/blob/wasi-0.1/preview1/docs.md#L1785 Blocked by: Support writable virtual files and non-stdio fd_write in WASI Preview1 #21, Implement fd_tell for WASI Preview1 on native and web backends #16
• Implement fd_filestat_set_size for WASI Preview1 on native and web backends #27 Implement fd_filestat_set_size for WASI Preview1 on native and web backends. Refs: https://github.com/WebAssembly/WASI/blob/wasi-0.1/preview1/docs.md#L1652 Blocked by: Support writable virtual files and non-stdio fd_write in WASI Preview1 #21, Expand fd_fdstat_get and fd_filestat_get metadata to better match WASI Preview1 #22
• Implement fd_filestat_set_times for WASI Preview1 on native and web backends #28 Implement fd_filestat_set_times for WASI Preview1 on native and web backends. Refs: https://github.com/WebAssembly/WASI/blob/wasi-0.1/preview1/docs.md#L1677 Blocked by: Expand fd_fdstat_get and fd_filestat_get metadata to better match WASI Preview1 #22
• Implement fd_advise for WASI Preview1 on native and web backends #29 Implement fd_advise for WASI Preview1 on native and web backends. Refs: https://github.com/WebAssembly/WASI/blob/wasi-0.1/preview1/docs.md#L1452 Blocked by: Expand fd_fdstat_get and fd_filestat_get metadata to better match WASI Preview1 #22
• Implement fd_allocate for WASI Preview1 on native and web backends #30 Implement fd_allocate for WASI Preview1 on native and web backends. Refs: https://github.com/WebAssembly/WASI/blob/wasi-0.1/preview1/docs.md#L1483 Blocked by: Support writable virtual files and non-stdio fd_write in WASI Preview1 #21
• Implement fd_datasync for WASI Preview1 on native and web backends #31 Implement fd_datasync for WASI Preview1 on native and web backends. Refs: https://github.com/WebAssembly/WASI/blob/wasi-0.1/preview1/docs.md#L1533 Blocked by: Support writable virtual files and non-stdio fd_write in WASI Preview1 #21
• Implement fd_sync for WASI Preview1 on native and web backends #32 Implement fd_sync for WASI Preview1 on native and web backends. Refs: https://github.com/WebAssembly/WASI/blob/wasi-0.1/preview1/docs.md#L1942 Blocked by: Support writable virtual files and non-stdio fd_write in WASI Preview1 #21
• Implement fd_renumber for WASI Preview1 on native and web backends #33 Implement fd_renumber for WASI Preview1 on native and web backends. Refs: https://github.com/WebAssembly/WASI/blob/wasi-0.1/preview1/docs.md#L1882

Phase 3: Path and Directory Semantics

• Make WASI Preview1 path_open honor lookupflags, oflags, fdflags, and rights #34 Make WASI Preview1 path_open honor lookupflags, oflags, fdflags, and rights. Refs: https://github.com/WebAssembly/WASI/blob/wasi-0.1/preview1/docs.md#L2141 Blocked by: Support writable virtual files and non-stdio fd_write in WASI Preview1 #21, Expand fd_fdstat_get and fd_filestat_get metadata to better match WASI Preview1 #22, Implement fd_fdstat_set_rights for WASI Preview1 on native and web backends #24
• Implement fd_readdir for WASI Preview1 on native and web backends #35 Implement fd_readdir for WASI Preview1 on native and web backends. Refs: https://github.com/WebAssembly/WASI/blob/wasi-0.1/preview1/docs.md#L1844 Blocked by: Make WASI Preview1 path_open honor lookupflags, oflags, fdflags, and rights #34
• Implement path_create_directory for WASI Preview1 on native and web backends #36 Implement path_create_directory for WASI Preview1 on native and web backends. Refs: https://github.com/WebAssembly/WASI/blob/wasi-0.1/preview1/docs.md#L2016 Blocked by: Make WASI Preview1 path_open honor lookupflags, oflags, fdflags, and rights #34
• Implement path_remove_directory for WASI Preview1 on native and web backends #37 Implement path_remove_directory for WASI Preview1 on native and web backends. Refs: https://github.com/WebAssembly/WASI/blob/wasi-0.1/preview1/docs.md#L2223 Blocked by: Implement path_create_directory for WASI Preview1 on native and web backends #36, Implement fd_readdir for WASI Preview1 on native and web backends #35
• Implement path_unlink_file for WASI Preview1 on native and web backends #38 Implement path_unlink_file for WASI Preview1 on native and web backends. Refs: https://github.com/WebAssembly/WASI/blob/wasi-0.1/preview1/docs.md#L2308 Blocked by: Make WASI Preview1 path_open honor lookupflags, oflags, fdflags, and rights #34, Support writable virtual files and non-stdio fd_write in WASI Preview1 #21
• Implement path_rename for WASI Preview1 on native and web backends #39 Implement path_rename for WASI Preview1 on native and web backends. Refs: https://github.com/WebAssembly/WASI/blob/wasi-0.1/preview1/docs.md#L2249 Blocked by: Make WASI Preview1 path_open honor lookupflags, oflags, fdflags, and rights #34, Implement path_create_directory for WASI Preview1 on native and web backends #36, Implement path_unlink_file for WASI Preview1 on native and web backends #38
• Implement path_link for WASI Preview1 on native and web backends #40 Implement path_link for WASI Preview1 on native and web backends. Refs: https://github.com/WebAssembly/WASI/blob/wasi-0.1/preview1/docs.md#L2107 Blocked by: Make WASI Preview1 path_open honor lookupflags, oflags, fdflags, and rights #34, Implement path_unlink_file for WASI Preview1 on native and web backends #38
• Implement path_symlink for WASI Preview1 on native and web backends #41 Implement path_symlink for WASI Preview1 on native and web backends. Refs: https://github.com/WebAssembly/WASI/blob/wasi-0.1/preview1/docs.md#L2280 Blocked by: Make WASI Preview1 path_open honor lookupflags, oflags, fdflags, and rights #34, Implement path_unlink_file for WASI Preview1 on native and web backends #38
• Implement path_readlink for WASI Preview1 on native and web backends #42 Implement path_readlink for WASI Preview1 on native and web backends. Refs: https://github.com/WebAssembly/WASI/blob/wasi-0.1/preview1/docs.md#L2192 Blocked by: Implement path_symlink for WASI Preview1 on native and web backends #41
• Implement path_filestat_set_times for WASI Preview1 on native and web backends #43 Implement path_filestat_set_times for WASI Preview1 on native and web backends. Refs: https://github.com/WebAssembly/WASI/blob/wasi-0.1/preview1/docs.md#L2070 Blocked by: Make WASI Preview1 path_open honor lookupflags, oflags, fdflags, and rights #34, Implement fd_filestat_set_times for WASI Preview1 on native and web backends #28

Phase 4: Events, Process, and Sockets

• Align poll_oneoff with broader WASI Preview1 semantics on native and web #44 Align poll_oneoff with broader WASI Preview1 semantics on native and web. Refs: https://github.com/WebAssembly/WASI/blob/wasi-0.1/preview1/docs.md#L2334
• Decide and document proc_raise support policy for WASI Preview1 native and web #45 Decide and document proc_raise support policy for WASI Preview1 native and web. Refs: https://github.com/WebAssembly/WASI/blob/wasi-0.1/preview1/docs.md#L2378
• Define native/web support policy for WASI Preview1 socket APIs #46 Define native/web support policy for WASI Preview1 socket APIs. Refs: https://github.com/WebAssembly/WASI/blob/wasi-0.1/preview1/docs.md#L2447 , https://github.com/WebAssembly/WASI/blob/wasi-0.1/preview1/docs.md#L2474 , https://github.com/WebAssembly/WASI/blob/wasi-0.1/preview1/docs.md#L2513 , https://github.com/WebAssembly/WASI/blob/wasi-0.1/preview1/docs.md#L2543
• Implement sock_accept for WASI Preview1 on native and web backends #47 Implement sock_accept for WASI Preview1 on native and web backends. Refs: https://github.com/WebAssembly/WASI/blob/wasi-0.1/preview1/docs.md#L2447 Blocked by: Define native/web support policy for WASI Preview1 socket APIs #46
• Implement sock_recv for WASI Preview1 on native and web backends #48 Implement sock_recv for WASI Preview1 on native and web backends. Refs: https://github.com/WebAssembly/WASI/blob/wasi-0.1/preview1/docs.md#L2474 Blocked by: Define native/web support policy for WASI Preview1 socket APIs #46
• Implement sock_send for WASI Preview1 on native and web backends #49 Implement sock_send for WASI Preview1 on native and web backends. Refs: https://github.com/WebAssembly/WASI/blob/wasi-0.1/preview1/docs.md#L2513 Blocked by: Define native/web support policy for WASI Preview1 socket APIs #46
• Implement sock_shutdown for WASI Preview1 on native and web backends #50 Implement sock_shutdown for WASI Preview1 on native and web backends. Refs: https://github.com/WebAssembly/WASI/blob/wasi-0.1/preview1/docs.md#L2543 Blocked by: Define native/web support policy for WASI Preview1 socket APIs #46

Phase 5: Verification and Documentation

• Add 46-function WASI Preview1 import-surface coverage tests across native, node, and web #17 Add 46-function WASI Preview1 import-surface coverage tests across native, node, and web. Refs: https://github.com/WebAssembly/WASI/blob/wasi-0.1/preview1/docs.md#L1282 , https://github.com/WebAssembly/WASI/blob/wasi-0.1/preview1/witx/wasi_snapshot_preview1.witx#L8
• Add syscall-level regression tests for newly supported WASI Preview1 APIs #51 Add syscall-level regression tests for newly supported WASI Preview1 APIs. Refs: https://github.com/WebAssembly/WASI/blob/wasi-0.1/preview1/docs.md#L1282 , https://github.com/WebAssembly/WASI/blob/wasi-0.1/preview1/witx/wasi_snapshot_preview1.witx#L8
• Add end-to-end WASI Preview1 fixtures for file, directory, and polling flows #52 Add end-to-end WASI Preview1 fixtures for file, directory, and polling flows. Refs: https://github.com/WebAssembly/WASI/blob/wasi-0.1/preview1/docs.md#L1818 , https://github.com/WebAssembly/WASI/blob/wasi-0.1/preview1/docs.md#L1844 , https://github.com/WebAssembly/WASI/blob/wasi-0.1/preview1/docs.md#L1987 , https://github.com/WebAssembly/WASI/blob/wasi-0.1/preview1/docs.md#L2141 , https://github.com/WebAssembly/WASI/blob/wasi-0.1/preview1/docs.md#L2334 Blocked by: Support writable virtual files and non-stdio fd_write in WASI Preview1 #21, Implement fd_readdir for WASI Preview1 on native and web backends #35, Align poll_oneoff with broader WASI Preview1 semantics on native and web #44
• Document a per-runtime WASI Preview1 support matrix #53 Document a per-runtime WASI Preview1 support matrix. Refs: https://github.com/WebAssembly/WASI/blob/wasi-0.1/preview1/docs.md#L1282 , https://github.com/WebAssembly/WASI/blob/wasi-0.1/preview1/witx/wasi_snapshot_preview1.witx#L8 Blocked by: Decide and document proc_raise support policy for WASI Preview1 native and web #45, Define native/web support policy for WASI Preview1 socket APIs #46
• Verify README and compatibility docs against actual WASI Preview1 backend behavior #54 Verify README and compatibility docs against actual WASI Preview1 backend behavior. Refs: https://github.com/WebAssembly/WASI/blob/wasi-0.1/preview1/docs.md#L1282 , https://github.com/WebAssembly/WASI/blob/wasi-0.1/preview1/witx/wasi_snapshot_preview1.witx#L8 Blocked by: Document a per-runtime WASI Preview1 support matrix #53

Exit Criteria

We should close this issue only when one of these is true:

1. Native and web backends support the full Preview1 surface with tested behavior.
2. The remaining exclusions are explicitly documented, and the package/docs stop implying complete Preview1 support.