CAS Blob Viewer

Render content-addressed vault blobs inline from durable sha256 references.

Why

Some vault workflows store file payloads once in a CAS layout:

blobs/sha256/<first-two>/<sha256>

Daily notes can then reference the durable hash instead of keeping duplicate attachment files around.

Syntax

Image/embed syntax:

![[cas-sha256-aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa|500]]

The plugin also accepts legacy cas:sha256:<hash> and blob://sha256/<hash> references, but the hyphenated form is preferred because native wikilinks handle it cleanly.

Code block fallback:

```cas-blob
sha256: aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
width: 500
caption: Pasted image
```

Scope and safety

• Read-only: the plugin reads blobs and optional metadata, but does not write or delete vault files.
• No network access.
• No duplicate preview files.
• Payload source of truth remains the CAS blob.

Settings

• Blob root: default blobs/sha256
• Metadata records file: default records/files.jsonl
• Maximum render bytes: default 25 MB

Live Preview

Live Preview rendering is off by default. Reading view rendering is the safe default because editor replacement widgets can interfere with opening large notes. Enable Live Preview rendering only after testing in a small note.

Installation and compatibility

CAS Blob Viewer is published on Obsidian Community as version 0.1.6 with a passed review and byte-for-byte build verification. A fresh installation through the Community catalog was verified on 13 November 2026 in Obsidian 1.15.0 on macOS Apple Silicon. Install it through Settings → Community plugins → Browse.

Manual installation uses main.js, manifest.json and styles.css from the 0.1.6 release. Place them in .obsidian/plugins/cas-blob-viewer/ in a test vault first. Both manual and Community installation have been tested separately. See publication evidence.

The plugin reads existing blobs; it does not create a CAS store or import attachments. All paths must remain relative to the current vault. Optional metadata must use record_type: "file", sha256, and optionally filename/mime_type. Invalid metadata rows are ignored. HTML, XHTML and text render as inert source, never as an executable web page. PDF content opens in the browser's PDF viewer. Images render inline. Unsupported content and oversized blobs display a card. The size limit controls preview reads; the hash syntax identifies the expected blob but does not verify its digest.

Rendering toggles require reloading the plugin. Live Preview remains experimental and off by default. Version 0.1.6 is validated on current desktop Obsidian on macOS; mobile and exact minimum-version execution are not claimed by those tests.

Development

Run npm ci, npm run lint, npm run typecheck, npm test, npm run build and npm run community:check. CodeMirror is supplied by Obsidian and kept external to the bundle. No runtime network request, external helper or package installation is required.

License

MIT; see LICENSE. No vendored third-party runtime code is included in the release bundle.