Visitor Web Router ABI v0
This document freezes the web-request-router ABI contract for Visitor Router v0.
Go implementation for this ABI contract lives under internal/routerabi.
Required Exports
All exports below are required and use Wasm i32 values for pointers, sizes, counts, and status codes.
| Export name | Kind | Signature |
|---|
memory | memory | linear memory |
input_ptr | function | () -> i32 |
input_cap | function | () -> i32 |
route | function | (path_size: i32, query_size: i32) -> i32 |
etag_ptr | function | () -> i32 |
etag_size | function | () -> i32 |
content_type_ptr | function | () -> i32 |
content_type_size | function | () -> i32 |
content_sha256_ptr | function | () -> i32 |
content_sha256_count | function | () -> i32 |
recipe_sha256_ptr | function | () -> i32 |
recipe_sha256_count | function | () -> i32 |
location_ptr | function | () -> i32 |
location_size | function | () -> i32 |
Input Buffer Layout
At input_ptr:
path_bytes | query_bytes (UTF-8 bytes only)route(path_size, query_size) receives sizes only- Host writes exactly
path_size + query_size bytes
path_size + query_size must be <= input_cap
Route Semantics
- Host calls
status := route(path_size, query_size).
- If
300 <= status <= 399: response is a redirect and location_size > 0 is required.
- If
status >= 400: response is an error.
- Otherwise: response body is resolved from
content[] digests folded through recipes[] digests.
Host Invariants (Must Enforce)
The host must validate all exported pointer/size/count outputs before reading bytes:
- all pointer+size reads must stay in wasm memory bounds
content_sha256_count >= 0recipe_sha256_count >= 0- digest arrays are exactly
count * 32 bytes
- for 3xx responses,
location_size > 0
Digest shape:
content_sha256_ptr points to content_sha256_count consecutive SHA-256 digestsrecipe_sha256_ptr points to recipe_sha256_count consecutive SHA-256 digests- each digest is 32 bytes
Reference Fixture
Reference fixture spec is in:
fixtures/visitor_router_v0_reference.json