README.md

@@ -69,6 +69,7 @@ Within files, `@`-prefixed markers at the beginning of paragraphs or headings de
 - `streamd todo --show-future` — Include tasks with future dates in the listing
 - `streamd edit [number]` — Edit a stream file by index (most recent first)
 - `streamd timesheet` — Generate time reports from `@Timesheet` markers
+- `streamd lsp` — Start the LSP server (stdin/stdout transport; see [Editor Integration](#editor-integration) below)
 
 ## Configuration
 
@@ -110,3 +111,68 @@ Running `streamd todo` finds all shards marked as open tasks and displays them n
 You can quickly edit or complete tasks by number:
 - `streamd todo 1 edit` opens task 1 in your editor at the correct line
 - `streamd todo 1 done` marks task 1 as done by inserting `@Done` after `@Task`
+
+## Editor Integration
+
+`streamd lsp` starts a Language Server Protocol server that provides IDE features for your stream markdown files. The server communicates over **stdin/stdout** and auto-activates only when a `.streamd.toml` file is present in the workspace root.
+
+### Features
+
+| Feature | Description |
+|---|---|
+| `@` completions | Suggests known markers from your config; conditional suggestions (e.g. `@Done` when `@Task` is on the line) |
+| Temporal snippets | `@` followed by a digit offers `YYYYMMDD` / `HHMMSS` format snippets |
+| Diagnostics | File-name format warnings (R15); timesheet errors (overlapping timecards, unclosed days) |
+| Document symbols | Shard tree exposed as outline symbols |
+| "Mark task as done" | Quick-fix code action: inserts `@Done` after `@Task` |
+| Workspace symbols | Search shards across all `.md` files |
+| References | Find all occurrences of an `@Marker` across the workspace |
+| Rename | Rename an `@Marker` across all files |
+
+### Zed
+
+Add to `~/.config/zed/settings.json`:
+
+```json
+{
+  "languages": {
+    "Markdown": {
+      "language_servers": ["streamd-lsp", "..."]
+    }
+  },
+  "lsp": {
+    "streamd-lsp": {
+      "binary": {
+        "path": "streamd",
+        "arguments": ["lsp"]
+      }
+    }
+  }
+}
+```
+
+The `"..."` keeps Zed's default Markdown servers (e.g. `marksman`) active alongside streamd.
+
+### Neovim (nvim-lspconfig)
+
+```lua
+local lspconfig = require('lspconfig')
+local configs = require('lspconfig.configs')
+
+if not configs.streamd then
+  configs.streamd = {
+    default_config = {
+      cmd = { 'streamd', 'lsp' },
+      filetypes = { 'markdown' },
+      root_dir = lspconfig.util.root_pattern('.streamd.toml'),
+      single_file_support = false,
+    },
+  }
+end
+
+lspconfig.streamd.setup {}
+```
+
+### VS Code (tasks.json / manual)
+
+Use any extension that lets you configure custom LSP servers, pointing `cmd` to `streamd lsp`.

REQUIREMENTS.md

@@ -400,6 +400,7 @@ Provide recursive search through the shard tree:
 | `streamd edit [n]` | Edit nth file (supports negative indexing for recent files) |
 | `streamd timesheet` | Generate formatted timesheet report with expected/actual hours |
 | `streamd completions <shell>` | Generate shell completions (bash, zsh, fish, elvish, powershell) |
+| `streamd lsp` | Start Language Server Protocol server over stdin/stdout |
 
 ### R21a: Daily Command Behavior
 
@@ -471,3 +472,53 @@ Multiple configurations can be merged:
 - Dimensions are combined (later configs can add new dimensions)
 - Markers are combined (later configs can add new markers)
 - This allows base configuration + domain-specific extensions
+
+---
+
+## LSP Server
+
+### R25: LSP Subcommand
+
+`streamd lsp` starts a Language Server Protocol server over stdin/stdout.
+
+**Workspace root resolution:**
+- The base folder is taken from `initializeParams.rootUri` (or `rootPath` as fallback).
+- R22/R23 global config resolution is bypassed in LSP mode.
+
+**Passive mode:**
+- If `.streamd.toml` is absent from the workspace root, the server enters passive mode: all requests return empty results and no diagnostics are published.
+
+**Config watching:**
+- The server registers a `workspace/didChangeWatchedFiles` watcher for `.streamd.toml`.
+- Config is reloaded without restarting the server when `.streamd.toml` changes.
+
+**Document sync:**
+- Full-document sync (`TextDocumentSyncKind::FULL`).
+- Re-parses on `didOpen`, `didChange`, and `didSave`.
+
+### R25a: LSP Completion
+
+- Trigger character: `@`
+- Returns marker names from the merged config (BasicTimesheetConfiguration + TaskConfiguration).
+- Conditional suggestions: if marker A is on the line and A has placements with `if_with: {B}`, B is offered with higher priority.
+- Temporal snippets: `@` followed by a digit offers `YYYYMMDD` and `HHMMSS` format snippets (R16).
+
+### R25b: LSP Diagnostics
+
+- **File-name format (R15)**: Warning when the file basename does not match `^(\d{8})(?:-(\d{4,6}))?.+\.md$`.
+- **Timesheet violations (R18)**: Error when a day ends without a break; Warning for overlapping timecards.
+
+### R25c: LSP Document Symbols
+
+- Returns the `LocalizedShard` tree as nested `DocumentSymbol` nodes.
+- Symbol names are derived from marker names or tag names.
+
+### R25d: LSP Code Actions
+
+- "Mark task as done": offered on any line containing `@Task` without `@Done`; inserts ` @Done` after `@Task`.
+
+### R25e: LSP Cross-file Features
+
+- `workspace/symbol`: searches all `.md` files in base folder (depth 1) for shards matching the query.
+- `textDocument/references`: finds all occurrences of the `@Marker` under the cursor across the workspace.
+- `textDocument/rename`: renames an `@Marker` across all files via `WorkspaceEdit`.

src/cli/commands/lsp.rs

@@ -418,7 +418,7 @@ impl Backend {
             .unwrap_or(chrono_tz::UTC);
 
         let config =
-            merge_repository_configuration(&*BasicTimesheetConfiguration, &*TaskConfiguration);
+            merge_repository_configuration(&BasicTimesheetConfiguration, &TaskConfiguration);
 
         Some(Arc::new(LspState {
             config,
@@ -437,6 +437,7 @@ impl Backend {
 #[tower_lsp::async_trait]
 impl LanguageServer for Backend {
     async fn initialize(&self, params: InitializeParams) -> Result<InitializeResult> {
+        #[allow(deprecated)]
         let root: Option<PathBuf> = params
             .root_uri
             .as_ref()
@@ -691,8 +692,13 @@ impl LanguageServer for Backend {
         let start_line = params.range.start.line as usize;
         let end_line = params.range.end.line as usize;
 
-        for line_idx in start_line..=end_line.min(lines.len().saturating_sub(1)) {
+        let range_end = end_line.min(lines.len().saturating_sub(1));
-            let line = &lines[line_idx];
+        for (line_idx, line) in lines
+            .iter()
+            .enumerate()
+            .skip(start_line)
+            .take(range_end.saturating_sub(start_line) + 1)
+        {
             if line.contains("@Task") && !line.contains("@Done") {
                 let new_line = line.replacen("@Task", "@Task @Done", 1);
                 let mut changes: std::collections::HashMap<Url, Vec<TextEdit>> =
@@ -745,7 +751,7 @@ impl LanguageServer for Backend {
             .filter_map(|e| e.ok())
         {
             let path = entry.path();
-            if !path.extension().map_or(false, |e| e == "md") {
+            if path.extension().is_none_or(|e| e != "md") {
                 continue;
             }
             let uri = match Url::from_file_path(path) {
@@ -809,7 +815,7 @@ impl LanguageServer for Backend {
             .filter_map(|e| e.ok())
         {
             let path = entry.path();
-            if !path.extension().map_or(false, |e| e == "md") {
+            if path.extension().is_none_or(|e| e != "md") {
                 continue;
             }
             let file_uri = match Url::from_file_path(path) {
@@ -893,7 +899,7 @@ impl LanguageServer for Backend {
             .filter_map(|e| e.ok())
         {
             let path = entry.path();
-            if !path.extension().map_or(false, |e| e == "md") {
+            if path.extension().is_none_or(|e| e != "md") {
                 continue;
             }
             let file_uri = match Url::from_file_path(path) {