aster

README

aster

Read any file, rendered. Terminal or browser.

brew install wildreason/tap/aster

Usage

aster readme.md                    # Markdown with colors and tables
aster page.html                    # HTML rendered as readable text
aster screenshot.png               # Image inline (iTerm2, Kitty, WezTerm)
aster changes.patch                # Diff with syntax highlighting
aster data.csv                     # CSV as formatted table
aster transcript.jsonl             # JSONL conversation viewer
aster data.json                    # JSON with highlighting
aster server.log                   # Plain text

aster pick                         # Choose from recently viewed files
aster latest                       # Open newest file in cwd

Pipe support:

git diff | aster
curl -s api.example.com | aster
cat log.jsonl | aster --type jsonl
curl -s example.com | aster        # HTML auto-detected

Browser

aster readme.md --share            # Open rendered HTML in browser
aster readme.md --port 3000        # Serve with live reload
aster data.csv --port 3000         # Sortable, filterable table
aster session.jsonl --port 3000    # Agent transcript as activity feed
aster ~/docs/ --port 8080          # Directory as web index
aster readme.md --html > out.html  # Self-contained HTML to stdout

Web features: live reload (SSE), syntax highlighting, copy button on code blocks, sortable tables (numeric-aware), TOC sidebar with scroll-spy, search (/ or Ctrl+K), CSV per-column filters, diff side-by-side with word-level highlighting, video player with speed controls.

Formats

Format	Extensions
Markdown	.md .markdown
HTML	.html .htm .xhtml
CSV / TSV	.csv .tsv
Unified diffs	.diff .patch
JSON	.json
JSONL transcripts	.jsonl
YAML	.yaml .yml
Images	.png .jpg .gif .webp .bmp .svg
Video	.mp4 .webm .mov
Plain text	.txt .log

Auto-detected from extension. Override with --type TYPE.

HTML is converted to markdown by a built-in tokenizer (no external dependency), then rendered like any other document: headings, lists, tables, code blocks, links and images all survive the trip.

Flags

--share      Open rendered HTML in the default browser
--port N     Serve as web page on localhost:N
--html       Export self-contained HTML to stdout
-t           Render in the terminal instead of the browser
--type TYPE  Force content type (md, html, json, jsonl, diff, txt, yaml, csv)
-n           Show source line numbers in gutter
-f           Follow mode (watch file for changes)

Navigation

Terminal:

j / k           Scroll down / up
d / u           Half-page down / up
g / G           Top / bottom
PgDn / PgUp     Full page down / up
q               Quit

Examples

# Git diffs in browser
git diff HEAD | aster --share
git diff main..feature | aster --port 3000

# Agent transcripts
aster session.jsonl --share

# Static export
git diff HEAD | aster --html > review.html
aster data.csv --html > table.html

# Directory index
aster ~/notes/ --port 8080

Install

Homebrew:

brew install wildreason/tap/aster

Build from source:

git clone https://github.com/wildreason/reader.git
cd reader
make install

Shell alias: alias as=aster

Terminal image rendering requires chafa: brew install chafa

License

MIT