diff --git a/README.md b/README.md
index dcdf689..da5f3cf 100644
--- a/README.md
+++ b/README.md
@@ -55,24 +55,19 @@ require('preview').setup({
 **Q: How do I override a preset?**
 
 ```lua
-local presets = require('preview.presets')
 require('preview').setup({
-  typst = vim.tbl_deep_extend('force', presets.typst, {
-    env = { TYPST_FONT_PATHS = '/usr/share/fonts' },
-  }),
+  typst = { env = { TYPST_FONT_PATHS = '/usr/share/fonts' } },
 })
 ```
 
 **Q: How do I automatically open the output file?**
 
 Set `open = true` on your provider (all built-in presets have this enabled) to
-open the output with `vim.ui.open()` after the first successful compilation.
-For a specific application, pass a command table:
+open the output with `vim.ui.open()` after the first successful compilation. For
+a specific application, pass a command table:
 
 ```lua
-typst = vim.tbl_deep_extend('force', presets.typst, {
-  open = { 'sioyek', '--new-instance' },
+require('preview').setup({
+  typst = { open = { 'sioyek', '--new-instance' } },
 })
 ```
-
-See `:h preview.nvim` for more information.
diff --git a/doc/preview.nvim.txt b/doc/preview.nvim.txt
index 3ed587a..0b44a91 100644
--- a/doc/preview.nvim.txt
+++ b/doc/preview.nvim.txt
@@ -1,6 +1,6 @@
 *preview.nvim.txt*                    Async document compilation for Neovim
 
-Author: Raphael
+Author:  Barrett Ruth <br.barrettruth@gmail.com>
 License: MIT
 
 ==============================================================================
@@ -20,19 +20,14 @@ REQUIREMENTS                                          *preview.nvim-requirements
 - A compiler binary for each configured provider (e.g. `typst`, `latexmk`)
 
 ==============================================================================
-INSTALLATION                                          *preview.nvim-installation*
+SETUP                                                  *preview.nvim-setup*
 
-With luarocks (recommended):
->
-    :Rocks install preview.nvim
-<
-
-With lazy.nvim:
->lua
+Load preview.nvim with your package manager. For example, with lazy.nvim: >lua
     {
       'barrettruth/preview.nvim',
     }
 <
+Call |preview.setup()| to configure providers before use.
 
 ==============================================================================
 CONFIGURATION                                      *preview.nvim-configuration*
@@ -42,9 +37,18 @@ Configure via `require('preview').setup()`.
                                                             *preview.setup()*
 setup({opts?})
 
-  `opts` is a mixed table. Array entries are preset names (see
-  |preview.nvim-presets|). Hash entries with table values are custom
-  provider configs keyed by filetype.
+  `opts` is a table where keys are preset names or filetypes. For each
+  key `k` with value `v` (excluding `debug`):
+
+  - If `k` is a preset name and `v` is `true`, the preset is registered
+    as-is under its filetype.
+  - If `k` is a preset name and `v` is a table, it is deep-merged with
+    the preset and registered under the preset's filetype.
+  - If `k` is not a preset name and `v` is a table, it is registered
+    directly as a custom provider keyed by filetype `k`.
+  - If `v` is `false`, the entry is skipped (no-op).
+
+  See |preview.nvim-presets| for available preset names.
 
   Fields:~
 
@@ -91,33 +95,28 @@ Context fields:~
   `root`    string     Project root (git root or file directory).
   `ft`      string     Filetype.
 
-Example using preset names:~
+Example enabling presets:~
 >lua
-    require('preview').setup({ 'typst', 'latex', 'markdown' })
+    require('preview').setup({ typst = true, latex = true, github = true })
 <
 
-Example with a custom provider:~
+Example overriding a preset field:~
 >lua
     require('preview').setup({
-      typst = {
-        cmd = { 'typst', 'compile' },
+      typst = { open = { 'sioyek', '--new-instance' } },
+    })
+<
+
+Example with a fully custom provider (key is not a preset name):~
+>lua
+    require('preview').setup({
+      rst = {
+        cmd = { 'rst2html' },
         args = function(ctx)
           return { ctx.file }
         end,
         output = function(ctx)
-          return ctx.file:gsub('%.typ$', '.pdf')
-        end,
-        error_parser = function(stderr, ctx)
-          local diagnostics = {}
-          for line, col, msg in stderr:gmatch('error:.-(%d+):(%d+):%s*(.-)%\n') do
-            table.insert(diagnostics, {
-              lnum = tonumber(line) - 1,
-              col = tonumber(col) - 1,
-              message = msg,
-              severity = vim.diagnostic.severity.ERROR,
-            })
-          end
-          return diagnostics
+          return ctx.file:gsub('%.rst$', '.html')
         end,
       },
     })
@@ -132,20 +131,17 @@ Import them from `preview.presets`:
   `presets.typst`              typst compile → PDF
   `presets.latex`              latexmk -pdf → PDF (with clean support)
   `presets.markdown`           pandoc → HTML (standalone, embedded)
-  `presets.github`             pandoc → HTML (GitHub-styled)
+  `presets.github`             pandoc → HTML (GitHub-styled, `-f gfm` input)
 
-Pass preset names as array entries to `setup()`:
+Enable presets with `preset_name = true`:
 >lua
-    require('preview').setup({ 'typst', 'latex', 'markdown' })
+    require('preview').setup({ typst = true, latex = true, github = true })
 <
 
-Override individual fields using `vim.tbl_deep_extend`:
+Override individual fields by passing a table instead of `true`:
 >lua
-    local presets = require('preview.presets')
     require('preview').setup({
-      typst = vim.tbl_deep_extend('force', presets.typst, {
-        env = { TYPST_FONT_PATHS = '/usr/share/fonts' },
-      }),
+      typst = { env = { TYPST_FONT_PATHS = '/usr/share/fonts' } },
     })
 <
 
@@ -160,7 +156,7 @@ COMMANDS                                              *preview.nvim-commands*
     `stop`       Kill active compilation for the current buffer.
     `clean`      Run the provider's clean command.
     `toggle`     Toggle auto-compile on save for the current buffer.
-    `status`     Echo compilation status (idle, compiling, watching).
+    `status`     Echo compilation status (idle, compiling, toggled).
 
 ==============================================================================
 API                                                        *preview.nvim-api*
@@ -175,9 +171,9 @@ preview.clean({bufnr?})                                    *preview.clean()*
     Run the provider's clean command for the buffer.
 
 preview.toggle({bufnr?})                                  *preview.toggle()*
-    Toggle watch mode for the buffer. When enabled, the buffer is
+    Toggle auto-compile for the buffer. When enabled, the buffer is
     immediately compiled and automatically recompiled on each save
-    (`BufWritePost`). Call again to stop watching.
+    (`BufWritePost`). Call again to stop.
 
 preview.status({bufnr?})                                  *preview.status()*
     Returns a |preview.Status| table.
@@ -186,7 +182,7 @@ preview.status({bufnr?})                                  *preview.status()*
 Status fields:~
 
   `compiling`    boolean    Whether compilation is active.
-  `watching`     boolean    Whether watch mode is active.
+  `watching`     boolean    Whether auto-compile is active.
   `provider`     string?    Name of the active provider.
   `output_file`  string?    Path to the output file.
 
@@ -207,12 +203,6 @@ preview.nvim fires User autocmds with structured data:
 `PreviewCompileFailed`   Compilation failed (non-zero exit).
                         data: `{ bufnr, provider, code, stderr }`
 
-`PreviewWatchStarted`   Watch mode enabled for a buffer.
-                        data: `{ bufnr, provider }`
-
-`PreviewWatchStopped`   Watch mode disabled for a buffer.
-                        data: `{ bufnr }`
-
 Example:~
 >lua
     vim.api.nvim_create_autocmd('User', {
diff --git a/lua/preview/compiler.lua b/lua/preview/compiler.lua
index 6907524..b0c7402 100644
--- a/lua/preview/compiler.lua
+++ b/lua/preview/compiler.lua
@@ -188,11 +188,6 @@ function M.toggle(bufnr, name, provider, ctx_builder)
     end,
   })
 
-  vim.api.nvim_exec_autocmds('User', {
-    pattern = 'PreviewWatchStarted',
-    data = { bufnr = bufnr, provider = name },
-  })
-
   M.compile(bufnr, name, provider, ctx_builder(bufnr))
 end
 
@@ -205,11 +200,6 @@ function M.unwatch(bufnr)
   vim.api.nvim_del_autocmd(au_id)
   watching[bufnr] = nil
   log.dbg('unwatched buffer %d', bufnr)
-
-  vim.api.nvim_exec_autocmds('User', {
-    pattern = 'PreviewWatchStopped',
-    data = { bufnr = bufnr },
-  })
 end
 
 ---@param bufnr integer
diff --git a/lua/preview/init.lua b/lua/preview/init.lua
index 968b201..e2cf794 100644
--- a/lua/preview/init.lua
+++ b/lua/preview/init.lua
@@ -68,15 +68,17 @@ function M.setup(opts)
     if k == 'debug' then
       vim.validate('preview.setup opts.debug', v, { 'boolean', 'string' })
       debug = v
-    elseif type(k) == 'number' then
-      vim.validate('preview.setup preset name', v, 'string')
-      local preset = presets[v]
+    elseif type(k) ~= 'number' then
+      local preset = presets[k]
       if preset then
-        providers[preset.ft] = preset
+        if v == true then
+          providers[preset.ft] = preset
+        elseif type(v) == 'table' then
+          providers[preset.ft] = vim.tbl_deep_extend('force', preset, v)
+        end
+      elseif type(v) == 'table' then
+        providers[k] = v
       end
-    else
-      vim.validate('preview.setup provider config', v, 'table')
-      providers[k] = v
     end
   end
 
diff --git a/lua/preview/presets.lua b/lua/preview/presets.lua
index 3579a8d..8a414e8 100644
--- a/lua/preview/presets.lua
+++ b/lua/preview/presets.lua
@@ -8,7 +8,7 @@ M.typst = {
     return { ctx.file }
   end,
   output = function(ctx)
-    return ctx.file:gsub('%.typ$', '.pdf')
+    return (ctx.file:gsub('%.typ$', '.pdf'))
   end,
   open = { 'xdg-open' },
 }
@@ -21,7 +21,7 @@ M.latex = {
     return { '-pdf', '-interaction=nonstopmode', ctx.file }
   end,
   output = function(ctx)
-    return ctx.file:gsub('%.tex$', '.pdf')
+    return (ctx.file:gsub('%.tex$', '.pdf'))
   end,
   clean = function(ctx)
     return { 'latexmk', '-c', ctx.file }
@@ -38,7 +38,7 @@ M.markdown = {
     return { ctx.file, '-s', '--embed-resources', '-o', output }
   end,
   output = function(ctx)
-    return ctx.file:gsub('%.md$', '.html')
+    return (ctx.file:gsub('%.md$', '.html'))
   end,
   clean = function(ctx)
     return { 'rm', '-f', (ctx.file:gsub('%.md$', '.html')) }
@@ -53,17 +53,19 @@ M.github = {
   args = function(ctx)
     local output = ctx.file:gsub('%.md$', '.html')
     return {
+      '-f',
+      'gfm',
       ctx.file,
       '-s',
       '--embed-resources',
       '--css',
-      'https://cdn.jsdelivr.net/gh/pixelbrackets/gfm-stylesheet@master/github.css',
+      'https://cdn.jsdelivr.net/gh/pixelbrackets/gfm-stylesheet@master/dist/gfm.css',
       '-o',
       output,
     }
   end,
   output = function(ctx)
-    return ctx.file:gsub('%.md$', '.html')
+    return (ctx.file:gsub('%.md$', '.html'))
   end,
   clean = function(ctx)
     return { 'rm', '-f', (ctx.file:gsub('%.md$', '.html')) }
diff --git a/spec/compiler_spec.lua b/spec/compiler_spec.lua
index 7360ceb..6802dee 100644
--- a/spec/compiler_spec.lua
+++ b/spec/compiler_spec.lua
@@ -190,31 +190,6 @@ describe('compiler', function()
       helpers.delete_buffer(bufnr)
     end)
 
-    it('fires PreviewWatchStarted event', function()
-      local bufnr = helpers.create_buffer({ 'hello' }, 'text')
-      vim.api.nvim_buf_set_name(bufnr, '/tmp/preview_test_watch_event.txt')
-
-      local fired = false
-      vim.api.nvim_create_autocmd('User', {
-        pattern = 'PreviewWatchStarted',
-        once = true,
-        callback = function()
-          fired = true
-        end,
-      })
-
-      local provider = { cmd = { 'echo', 'ok' } }
-      local ctx_builder = function(b)
-        return { bufnr = b, file = '/tmp/preview_test_watch_event.txt', root = '/tmp', ft = 'text' }
-      end
-
-      compiler.toggle(bufnr, 'echo', provider, ctx_builder)
-      assert.is_true(fired)
-
-      compiler.unwatch(bufnr)
-      helpers.delete_buffer(bufnr)
-    end)
-
     it('toggles off when called again', function()
       local bufnr = helpers.create_buffer({ 'hello' }, 'text')
       vim.api.nvim_buf_set_name(bufnr, '/tmp/preview_test_watch_toggle.txt')
@@ -233,32 +208,6 @@ describe('compiler', function()
       helpers.delete_buffer(bufnr)
     end)
 
-    it('fires PreviewWatchStopped on unwatch', function()
-      local bufnr = helpers.create_buffer({ 'hello' }, 'text')
-      vim.api.nvim_buf_set_name(bufnr, '/tmp/preview_test_watch_stop.txt')
-
-      local stopped = false
-      vim.api.nvim_create_autocmd('User', {
-        pattern = 'PreviewWatchStopped',
-        once = true,
-        callback = function()
-          stopped = true
-        end,
-      })
-
-      local provider = { cmd = { 'echo', 'ok' } }
-      local ctx_builder = function(b)
-        return { bufnr = b, file = '/tmp/preview_test_watch_stop.txt', root = '/tmp', ft = 'text' }
-      end
-
-      compiler.toggle(bufnr, 'echo', provider, ctx_builder)
-      compiler.unwatch(bufnr)
-      assert.is_true(stopped)
-      assert.is_nil(compiler._test.watching[bufnr])
-
-      helpers.delete_buffer(bufnr)
-    end)
-
     it('stop_all clears watches', function()
       local bufnr = helpers.create_buffer({ 'hello' }, 'text')
       vim.api.nvim_buf_set_name(bufnr, '/tmp/preview_test_watch_stopall.txt')
diff --git a/spec/init_spec.lua b/spec/init_spec.lua
index 7921aeb..5b97c8a 100644
--- a/spec/init_spec.lua
+++ b/spec/init_spec.lua
@@ -22,7 +22,7 @@ describe('preview', function()
       assert.are.same({}, config.providers)
     end)
 
-    it('accepts full provider config via hash entry', function()
+    it('merges override table with matching preset', function()
       helpers.reset_config({
         typst = {
           cmd = { 'typst', 'compile' },
@@ -33,8 +33,8 @@ describe('preview', function()
       assert.is_not_nil(config.providers.typst)
     end)
 
-    it('resolves array preset names to provider configs', function()
-      helpers.reset_config({ 'typst', 'markdown' })
+    it('resolves preset = true to provider config', function()
+      helpers.reset_config({ typst = true, markdown = true })
       local config = require('preview').get_config()
       local presets = require('preview.presets')
       assert.are.same(presets.typst, config.providers.typst)
@@ -42,14 +42,14 @@ describe('preview', function()
     end)
 
     it('resolves latex preset under tex filetype', function()
-      helpers.reset_config({ 'latex' })
+      helpers.reset_config({ latex = true })
       local config = require('preview').get_config()
       local presets = require('preview.presets')
       assert.are.same(presets.latex, config.providers.tex)
     end)
 
     it('resolves github preset under markdown filetype', function()
-      helpers.reset_config({ 'github' })
+      helpers.reset_config({ github = true })
       local config = require('preview').get_config()
       local presets = require('preview.presets')
       assert.are.same(presets.github, config.providers.markdown)
@@ -59,7 +59,7 @@ describe('preview', function()
   describe('resolve_provider', function()
     before_each(function()
       helpers.reset_config({
-        typst = { cmd = { 'typst', 'compile' } },
+        typst = true,
       })
       preview = require('preview')
     end)
diff --git a/spec/presets_spec.lua b/spec/presets_spec.lua
index 2eba98f..b8572c5 100644
--- a/spec/presets_spec.lua
+++ b/spec/presets_spec.lua
@@ -139,16 +139,31 @@ describe('presets', function()
       local args = presets.github.args(md_ctx)
       assert.is_table(args)
       assert.are.same({
+        '-f',
+        'gfm',
         '/tmp/document.md',
         '-s',
         '--embed-resources',
         '--css',
-        'https://cdn.jsdelivr.net/gh/pixelbrackets/gfm-stylesheet@master/github.css',
+        'https://cdn.jsdelivr.net/gh/pixelbrackets/gfm-stylesheet@master/dist/gfm.css',
         '-o',
         '/tmp/document.html',
       }, args)
     end)
 
+    it('args include -f and gfm flags', function()
+      local args = presets.github.args(md_ctx)
+      local idx = nil
+      for i, v in ipairs(args) do
+        if v == '-f' then
+          idx = i
+          break
+        end
+      end
+      assert.is_not_nil(idx)
+      assert.are.equal('gfm', args[idx + 1])
+    end)
+
     it('returns html output path', function()
       local output = presets.github.output(md_ctx)
       assert.is_string(output)