diff --git a/README.md b/README.md
index d83518f..373e454 100644
--- a/README.md
+++ b/README.md
@@ -229,6 +229,9 @@ require('nuwiki').setup({
       template_default = 'default',
       template_ext     = '.tpl',
       css_name         = 'style.css',
+      custom_wiki2html = '',             -- external converter; empty = built-in renderer
+      custom_wiki2html_args = '',        -- extra args appended to the converter call
+      base_url         = '',             -- public URL prefix for RSS item links
       auto_export      = false,          -- export on save
       auto_toc         = false,          -- auto-refresh TOC on save
       auto_generate_links = false,       -- regen Generated Links on save
@@ -358,6 +361,9 @@ Each is a boolean. All default to `true` except `mouse`.
 | `css_name` | string | `'style.css'` | stylesheet filename |
 | `auto_export` | bool | `false` | `true` \| `false` (export on save) |
 | `html_filename_parameterization` | bool | `false` | `true` \| `false` |
+| `custom_wiki2html` | string | `''` | external converter command; empty = built-in renderer. Called as `<cmd> <force> <syntax> <ext> <out_dir> <in_file> <css> <tpl_path> <tpl_default> <tpl_ext> <root_path> <args>` (`-` for empty optionals), matching vimwiki |
+| `custom_wiki2html_args` | string | `''` | extra args appended to the `custom_wiki2html` call |
+| `base_url` | string | `''` | public URL prefix; when set, diary RSS item links become `<base_url><diary_rel_path>/<date>.html` instead of `file://` |
 | `exclude_files` | list | `{}` | glob patterns |
 | `color_dic` | table | `{}` | `{ name = 'color', … }` |
 
diff --git a/crates/nuwiki-lsp/src/commands.rs b/crates/nuwiki-lsp/src/commands.rs
index 9306830..526bd99 100644
--- a/crates/nuwiki-lsp/src/commands.rs
+++ b/crates/nuwiki-lsp/src/commands.rs
@@ -1143,7 +1143,7 @@ fn export_current(
         })));
     }
     let name = crate::index::page_name_from_uri(&p.uri, Some(&cfg.root));
-    let outcome = match crate::commands::export_ops::write_page(&doc.ast, &name, cfg) {
+    let outcome = match crate::commands::export_ops::write_page(&doc.ast, &name, cfg, false) {
         Ok(o) => o,
         Err(e) => return Err(format!("nuwiki.export.currentToHtml: {e}")),
     };
@@ -1222,7 +1222,7 @@ fn export_all(backend: &Backend, args: Vec<Value>, force: bool) -> Result<Option
                 }
             }
         }
-        match crate::commands::export_ops::write_page(&ast, &name, &cfg) {
+        match crate::commands::export_ops::write_page(&ast, &name, &cfg, force) {
             Ok(outcome) => exported.push(outcome.to_json()),
             Err(e) => skipped.push(serde_json::json!({"uri": uri, "reason": e.to_string()})),
         }
@@ -3342,6 +3342,7 @@ pub mod export_ops {
         doc: &DocumentNode,
         name: &str,
         cfg: &WikiConfig,
+        force: bool,
     ) -> std::io::Result<PageExport> {
         if is_excluded(&cfg.html.exclude_files, name) {
             return Err(std::io::Error::new(
@@ -3349,6 +3350,11 @@ pub mod export_ops {
                 format!("excluded by exclude_files: {name}"),
             ));
         }
+        // When a `custom_wiki2html` converter is configured, hand the page off
+        // to it instead of the built-in renderer (vimwiki parity).
+        if !cfg.html.custom_wiki2html.trim().is_empty() {
+            return run_custom_wiki2html(name, cfg, force);
+        }
         let template_source = template_for(&cfg.html, doc);
         let template = load_template(&template_source)
             .unwrap_or_else(|| fallback_template(&cfg.html.css_name));
@@ -3378,6 +3384,86 @@ pub mod export_ops {
         })
     }
 
+    /// `sh`-quote a path/string for the `custom_wiki2html` command line.
+    fn sh_quote(s: &str) -> String {
+        format!("'{}'", s.replace('\'', "'\\''"))
+    }
+
+    /// Run an external `custom_wiki2html` converter for `name`, mirroring
+    /// vimwiki's argument order:
+    ///   script force syntax ext output_dir input_file css_file
+    ///          template_path template_default template_ext root_path args
+    /// Empty optional args are passed as `-` (vimwiki convention). The script
+    /// is responsible for writing the output file; we return the path it is
+    /// expected to produce (`output_path_for`).
+    fn run_custom_wiki2html(
+        name: &str,
+        cfg: &WikiConfig,
+        force: bool,
+    ) -> std::io::Result<PageExport> {
+        let h = &cfg.html;
+        let input = cfg.root.join(format!("{name}{}", cfg.file_extension));
+        std::fs::create_dir_all(&h.html_path)?;
+        let css = crate::export::css_path(h);
+        let ext = cfg.file_extension.trim_start_matches('.');
+        let dash = |s: &str| {
+            if s.is_empty() {
+                "-".to_string()
+            } else {
+                s.to_string()
+            }
+        };
+        let tpl_path = if h.template_path.as_os_str().is_empty() {
+            "-".to_string()
+        } else {
+            sh_quote(&h.template_path.display().to_string())
+        };
+        let root_path = {
+            let rp = crate::export::compute_root_path(name);
+            if rp.is_empty() {
+                "-".to_string()
+            } else {
+                sh_quote(&rp)
+            }
+        };
+        let cmd = format!(
+            "{} {} {} {} {} {} {} {} {} {} {} {}",
+            h.custom_wiki2html,
+            if force { 1 } else { 0 },
+            cfg.syntax,
+            ext,
+            sh_quote(&h.html_path.display().to_string()),
+            sh_quote(&input.display().to_string()),
+            sh_quote(&css.display().to_string()),
+            tpl_path,
+            dash(&h.template_default),
+            dash(&h.template_ext),
+            root_path,
+            dash(h.custom_wiki2html_args.trim()),
+        );
+        let status = std::process::Command::new("sh")
+            .arg("-c")
+            .arg(&cmd)
+            .status()
+            .map_err(|e| {
+                std::io::Error::new(
+                    std::io::ErrorKind::Other,
+                    format!("custom_wiki2html spawn failed: {e}"),
+                )
+            })?;
+        if !status.success() {
+            return Err(std::io::Error::new(
+                std::io::ErrorKind::Other,
+                format!("custom_wiki2html exited with {status}"),
+            ));
+        }
+        Ok(PageExport {
+            page: name.to_string(),
+            output_path: output_path_for(&cfg.html, name),
+            source_uri: tower_lsp::lsp_types::Url::from_file_path(&input).ok(),
+        })
+    }
+
     /// Two-tier template load. Returns the resolved template body, or
     /// `None` if neither file exists — caller falls back to the built-in
     /// template.
@@ -3423,12 +3509,29 @@ pub mod export_ops {
 "#,
         );
         xml.push_str(&format!("<title>{}</title>\n", xml_escape(&cfg.name)));
+        // `base_url` (per-wiki) prefixes the feed + item links so a hosted
+        // feed points at public URLs rather than local `file://` paths.
+        let base_url = cfg.html.base_url.trim();
+        if !base_url.is_empty() {
+            xml.push_str(&format!("<link>{}</link>\n", xml_escape(base_url)));
+        }
         xml.push_str("<description>nuwiki diary</description>\n");
         for e in sorted {
+            // With base_url set, build a public URL from the diary path + date;
+            // otherwise fall back to the entry's `file://` URI.
+            let link = if base_url.is_empty() {
+                e.uri.as_str().to_string()
+            } else {
+                format!(
+                    "{base_url}{}/{}.html",
+                    cfg.diary_rel_path.trim_matches('/'),
+                    e.date.format()
+                )
+            };
             xml.push_str("<item>");
             xml.push_str(&format!("<title>{}</title>", e.date.format()));
-            xml.push_str(&format!("<link>{}</link>", e.uri.as_str()));
-            xml.push_str(&format!("<guid>{}</guid>", e.uri.as_str()));
+            xml.push_str(&format!("<link>{}</link>", xml_escape(&link)));
+            xml.push_str(&format!("<guid>{}</guid>", xml_escape(&link)));
             xml.push_str("</item>\n");
         }
         xml.push_str("</channel></rss>\n");
diff --git a/crates/nuwiki-lsp/src/config.rs b/crates/nuwiki-lsp/src/config.rs
index 46596c3..94a0ecb 100644
--- a/crates/nuwiki-lsp/src/config.rs
+++ b/crates/nuwiki-lsp/src/config.rs
@@ -130,6 +130,13 @@ pub struct HtmlConfig {
     /// renderer falls back to `class="color-<name>"` when a name
     /// isn't in the dict.
     pub color_dic: std::collections::HashMap<String, String>,
+    /// External wiki→HTML converter (vimwiki's `custom_wiki2html`). When
+    /// non-empty, export shells out to it instead of the built-in renderer.
+    pub custom_wiki2html: String,
+    /// Extra args appended to the `custom_wiki2html` invocation.
+    pub custom_wiki2html_args: String,
+    /// URL prefix prepended to RSS feed / diary item links (`base_url`).
+    pub base_url: String,
 }
 
 impl Default for HtmlConfig {
@@ -145,6 +152,9 @@ impl Default for HtmlConfig {
             html_filename_parameterization: false,
             exclude_files: Vec::new(),
             color_dic: std::collections::HashMap::new(),
+            custom_wiki2html: String::new(),
+            custom_wiki2html_args: String::new(),
+            base_url: String::new(),
         }
     }
 }
@@ -634,6 +644,12 @@ struct RawWiki {
     exclude_files: Option<Vec<String>>,
     #[serde(default)]
     color_dic: Option<std::collections::HashMap<String, String>>,
+    #[serde(default)]
+    custom_wiki2html: Option<String>,
+    #[serde(default)]
+    custom_wiki2html_args: Option<String>,
+    #[serde(default)]
+    base_url: Option<String>,
     // per-wiki keys mirroring vimwiki globals. All optional so
     // existing single-wiki configs migrate without touching anything.
     #[serde(default)]
@@ -720,6 +736,15 @@ impl From<RawWiki> for WikiConfig {
         if let Some(v) = r.color_dic {
             html.color_dic = v;
         }
+        if let Some(s) = r.custom_wiki2html {
+            html.custom_wiki2html = s;
+        }
+        if let Some(s) = r.custom_wiki2html_args {
+            html.custom_wiki2html_args = s;
+        }
+        if let Some(s) = r.base_url {
+            html.base_url = s;
+        }
         let d = wiki_defaults();
         WikiConfig {
             name: r.name.unwrap_or(derived_name),
diff --git a/crates/nuwiki-lsp/src/lib.rs b/crates/nuwiki-lsp/src/lib.rs
index 0f6d5b1..7dd1d31 100644
--- a/crates/nuwiki-lsp/src/lib.rs
+++ b/crates/nuwiki-lsp/src/lib.rs
@@ -728,7 +728,7 @@ impl LanguageServer for Backend {
             return;
         }
         let name = index::page_name_from_uri(&uri, Some(&wiki.config.root));
-        let outcome = commands::export_ops::write_page(&doc.ast, &name, &wiki.config);
+        let outcome = commands::export_ops::write_page(&doc.ast, &name, &wiki.config, false);
         drop(doc);
         match outcome {
             Ok(out) => {
diff --git a/crates/nuwiki-lsp/tests/html_export.rs b/crates/nuwiki-lsp/tests/html_export.rs
index 7a729f2..5235483 100644
--- a/crates/nuwiki-lsp/tests/html_export.rs
+++ b/crates/nuwiki-lsp/tests/html_export.rs
@@ -428,7 +428,7 @@ fn write_page_writes_html_to_disk() {
     let mut c = WikiConfig::from_root(root.clone());
     c.html = HtmlConfig::from_root(&root);
     let ast = parse("= Hello =\nworld\n");
-    let outcome = nuwiki_lsp::commands::export_ops::write_page(&ast, "Hello", &c).unwrap();
+    let outcome = nuwiki_lsp::commands::export_ops::write_page(&ast, "Hello", &c, false).unwrap();
     assert_eq!(outcome.page, "Hello");
     assert!(outcome.output_path.exists());
     let body = std::fs::read_to_string(&outcome.output_path).unwrap();
@@ -442,7 +442,7 @@ fn write_page_creates_subdirs() {
     c.html = HtmlConfig::from_root(&root);
     let ast = parse("= Daily =\n");
     let outcome =
-        nuwiki_lsp::commands::export_ops::write_page(&ast, "diary/2026-05-11", &c).unwrap();
+        nuwiki_lsp::commands::export_ops::write_page(&ast, "diary/2026-05-11", &c, false).unwrap();
     assert!(outcome.output_path.exists());
     assert!(outcome
         .output_path
@@ -463,7 +463,7 @@ fn write_page_uses_template_file_when_present() {
     )
     .unwrap();
     let ast = parse("%title T\n= H =\nbody\n");
-    let outcome = nuwiki_lsp::commands::export_ops::write_page(&ast, "P", &c).unwrap();
+    let outcome = nuwiki_lsp::commands::export_ops::write_page(&ast, "P", &c, false).unwrap();
     let body = std::fs::read_to_string(outcome.output_path).unwrap();
     assert!(body.starts_with("<x>T|"));
     assert!(body.ends_with("</x>"));
@@ -518,6 +518,60 @@ fn write_rss_emits_valid_xml_with_entries() {
     let i11 = xml.find("2026-05-11").unwrap();
     let i10 = xml.find("2026-05-10").unwrap();
     assert!(i11 < i10);
+    // No base_url → item links keep the file:// URI.
+    assert!(xml.contains("<link>file:///tmp/diary/2026-05-11.wiki</link>"));
+}
+
+#[test]
+fn write_rss_uses_base_url_for_public_links() {
+    use nuwiki_lsp::diary::DiaryEntry;
+    use tower_lsp::lsp_types::Url;
+
+    let root = temp_root("rss_base");
+    let mut c = WikiConfig::from_root(root.clone());
+    c.html = HtmlConfig::from_root(&root);
+    c.html.base_url = "https://example.com/wiki/".into();
+    c.diary_rel_path = "diary".into();
+    let entries = vec![DiaryEntry {
+        date: DiaryDate::from_ymd(2026, 5, 11).unwrap(),
+        uri: Url::parse("file:///tmp/diary/2026-05-11.wiki").unwrap(),
+    }];
+    let path = nuwiki_lsp::commands::export_ops::write_rss(&c, &entries).unwrap();
+    let xml = std::fs::read_to_string(&path).unwrap();
+    // Channel + item links use the public base URL, not file://.
+    assert!(xml.contains("<link>https://example.com/wiki/</link>"));
+    assert!(xml.contains("<link>https://example.com/wiki/diary/2026-05-11.html</link>"));
+    assert!(xml.contains("<guid>https://example.com/wiki/diary/2026-05-11.html</guid>"));
+    assert!(!xml.contains("file:///tmp/diary"));
+}
+
+#[test]
+fn write_page_invokes_custom_wiki2html_converter() {
+    let root = temp_root("custom_w2h");
+    let mut c = WikiConfig::from_root(root.clone());
+    c.html = HtmlConfig::from_root(&root);
+    // Source file must exist on disk — the converter receives its path.
+    std::fs::write(root.join("Hello.wiki"), "= Hello =\nworld\n").unwrap();
+    // A tiny shell "converter": writes a marker into the output path it is told
+    // to produce. nuwiki appends args positionally after `_` ($0), so
+    // $1=force, $2=syntax, $3=ext, $4=output_dir, $5=input_file, …
+    let script = "mkdir -p \"$4\" && printf 'CUSTOM:%s' \"$5\" > \"$4\"/Hello.html";
+    c.html.custom_wiki2html = format!("sh -c {} _", shell_words_quote(script));
+    let outcome =
+        nuwiki_lsp::commands::export_ops::write_page(&parse("= Hello =\n"), "Hello", &c, true)
+            .unwrap();
+    assert_eq!(outcome.page, "Hello");
+    assert!(outcome.output_path.exists(), "converter must produce output");
+    let body = std::fs::read_to_string(&outcome.output_path).unwrap();
+    assert!(
+        body.starts_with("CUSTOM:"),
+        "marker from converter, got {body}"
+    );
+}
+
+/// Minimal single-quote shell escaping for the test command above.
+fn shell_words_quote(s: &str) -> String {
+    format!("'{}'", s.replace('\'', "'\\''"))
 }
 
 // ===== COMMANDS list completeness =====
diff --git a/crates/nuwiki-lsp/tests/index_and_config.rs b/crates/nuwiki-lsp/tests/index_and_config.rs
index 9aa2f3b..a3a5279 100644
--- a/crates/nuwiki-lsp/tests/index_and_config.rs
+++ b/crates/nuwiki-lsp/tests/index_and_config.rs
@@ -284,6 +284,10 @@ fn defaults_carry_vimwiki_per_wiki_keys() {
     assert_eq!(cfg.links_header, "Generated Links");
     assert_eq!(cfg.tags_header, "Generated Tags");
     assert_eq!(cfg.listsym_rejected, "-");
+    // No external converter / public base URL by default.
+    assert_eq!(cfg.html.custom_wiki2html, "");
+    assert_eq!(cfg.html.custom_wiki2html_args, "");
+    assert_eq!(cfg.html.base_url, "");
 }
 
 #[test]
@@ -312,6 +316,9 @@ fn raw_wiki_parses_every_new_key() {
             "links_header": "All Pages",
             "tags_header": "Tag Index",
             "tags_header_level": 3,
+            "custom_wiki2html": "~/bin/my_wiki2html.sh",
+            "custom_wiki2html_args": "--flag",
+            "base_url": "https://example.com/wiki/",
         }],
     }));
     let w = &cfg.wikis[0];
@@ -338,6 +345,11 @@ fn raw_wiki_parses_every_new_key() {
     assert_eq!(w.links_header_level, 1); // unspecified → default
     assert_eq!(w.tags_header, "Tag Index");
     assert_eq!(w.tags_header_level, 3);
+    // custom_wiki2html keeps the literal command string (tilde-expansion is
+    // the converter's job, not ours); args + base_url round-trip verbatim.
+    assert_eq!(w.html.custom_wiki2html, "~/bin/my_wiki2html.sh");
+    assert_eq!(w.html.custom_wiki2html_args, "--flag");
+    assert_eq!(w.html.base_url, "https://example.com/wiki/");
 
     // The parsed keys drive a date-mode, Sunday-start diary calendar:
     // a weekly note is the week-start date (YYYY-MM-DD), stepping ±7 days.
diff --git a/development/vimwiki-gap.md b/development/vimwiki-gap.md
index f3d58d8..583a180 100644
--- a/development/vimwiki-gap.md
+++ b/development/vimwiki-gap.md
@@ -118,8 +118,22 @@ fix site.
   custom rejected glyph both lexes and round-trips. Tests:
   `listsyms::custom_rejected_glyph_is_honoured` + config round-trip in
   `index_and_config.rs`.
-- [ ] **`custom_wiki2html` (+`_args`)** and **`base_url`** — external HTML
-  converter hook + export URL prefix. _Fix:_ `config.rs` `HtmlConfig`.
+- [x] **`custom_wiki2html` (+`_args`)** and **`base_url`** — external HTML
+  converter hook + export URL prefix. _Fix:_ `HtmlConfig` (`config.rs`) gained
+  `custom_wiki2html`, `custom_wiki2html_args`, `base_url` (all default `""`,
+  round-tripped through `RawWiki`/`From`/defaults). `write_page`
+  (`commands.rs`) now takes a `force` flag and, when `custom_wiki2html` is set,
+  hands the page to `run_custom_wiki2html()` — which shells out via `sh -c`
+  with vimwiki's exact arg order (`<cmd> <force> <syntax> <ext> <out_dir>
+  <in_file> <css> <tpl_path> <tpl_default> <tpl_ext> <root_path> <args>`, `-`
+  for empty optionals) instead of the built-in renderer. `force` is threaded
+  through `export_current` (false), `export_all` (its own flag), and the
+  `did_save` auto-export path (false). `write_rss` now prefixes the channel +
+  item links with `base_url` (`<base_url><diary_rel_path>/<date>.html`) when
+  set, falling back to the entry's `file://` URI otherwise. Tests:
+  `write_page_invokes_custom_wiki2html_converter`,
+  `write_rss_uses_base_url_for_public_links` (`html_export.rs`), config
+  round-trip + defaults (`index_and_config.rs`).
 - [ ] **`map_prefix`** — `<Leader>w` hardcoded across the map layer.
   _Fix:_ `plugin/nuwiki.vim`, `lua/nuwiki/keymaps.lua`, `ftplugin/vimwiki.vim`.
 - [x] **`<M-CR>` badd-link** — was mouse-only (`<MiddleMouse>`) / command-only
diff --git a/doc/nuwiki.txt b/doc/nuwiki.txt
index 51ce036..2028ab9 100644
--- a/doc/nuwiki.txt
+++ b/doc/nuwiki.txt
@@ -194,6 +194,16 @@ match upstream vimwiki.
 `template_default`       `'default'`
 `template_ext`           `'.tpl'`
 `css_name`               `'style.css'`
+`custom_wiki2html`       `''` — external converter command. When set, export
+                         shells out to it instead of the built-in renderer,
+                         called as: <cmd> <force> <syntax> <ext> <out_dir>
+                         <in_file> <css> <tpl_path> <tpl_default> <tpl_ext>
+                         <root_path> <args> (`-` for empty optionals), matching
+                         vimwiki's `g:vimwiki_custom_wiki2html` contract.
+`custom_wiki2html_args`  `''` — extra args appended to the converter call.
+`base_url`               `''` — public URL prefix. When set, diary RSS item
+                         links become <base_url><diary_rel_path>/<date>.html
+                         instead of local `file://` paths.
 `auto_export`            `false` — export to HTML on save.
 `auto_toc`               `false` — refresh TOC on save.
 `auto_generate_links`    `false` — regen an existing Generated Links section
diff --git a/lua/nuwiki/config.lua b/lua/nuwiki/config.lua
index 0295603..5dfcb97 100644
--- a/lua/nuwiki/config.lua
+++ b/lua/nuwiki/config.lua
@@ -26,7 +26,8 @@ M.defaults = {
   --   html_path, template_path, template_default, template_ext,
   --   template_date_format, css_name, auto_export, auto_toc,
   --   auto_generate_links, auto_generate_tags, auto_diary_index,
-  --   html_filename_parameterization, exclude_files, color_dic
+  --   html_filename_parameterization, exclude_files, color_dic,
+  --   custom_wiki2html, custom_wiki2html_args, base_url,
   --   toc_header, toc_header_level, links_header, links_header_level,
   --   tags_header, tags_header_level,
   --   listsyms, listsym_rejected, listsyms_propagate, list_margin,