pikchr.c built to a standalone WASI module (-DPIKCHR_SHELL -sSTANDALONE_WASM) and run under wazero, so the CGO-free constraint holds. Its own CLI reads - and writes SVG, so the host ABI is a pipe: no memory marshalling to get wrong. Renders text/x-pikchr artifacts and pikchr fences inside markdown; a diagram that will not compile degrades to its source plus the compiler's message.

SVG does NOT ride the document policy. It gets a narrow allow-list derived by enumerating what the module actually emits (six elements, a closed geometry/paint attribute set, no script/href/foreignObject), so even a hole in Pikchr's own label escaping cannot reach a page. Fence placeholders are alphanumeric with a per-render nonce: an HTML parser rewrites control bytes, so a NUL-based marker does not survive sanitizing (caught by test). Provenance and the rebuild recipe are in the ledger. check-in: 58fe4cf214 user: dmestas tags: trunk