diff --git a/static/sessions.js b/static/sessions.js
index ec53094f..e75785a9 100644
--- a/static/sessions.js
+++ b/static/sessions.js
@@ -934,7 +934,11 @@ async function newSession(flash, options={}){
     };
     if(S.session&&S.session.session_id) reqBody.prev_session_id=S.session.session_id;
     if(options&&options.worktree) reqBody.worktree=true;
-    if(_activeProject&&_activeProject!==NO_PROJECT_FILTER) reqBody.project_id=_activeProject;
+    if(Object.prototype.hasOwnProperty.call(options,'project_id')){
+      reqBody.project_id=options.project_id;
+    } else if(_activeProject&&_activeProject!==NO_PROJECT_FILTER){
+      reqBody.project_id=_activeProject;
+    }
     // Forward a pre-session toolset override only from the empty composer (#4490).
     if(!S.session && Array.isArray(S._pendingSessionToolsets)) reqBody.enabled_toolsets=S._pendingSessionToolsets;
     const modelSelForNew=$('modelSelect');
@@ -6144,6 +6148,28 @@ function _renderSidebarRowsFromRawSessions(sessionsRaw, referenceSessionsRaw){
   return _attachChildSessionsToSidebarRows(_collapseSessionLineageForSidebar(sessionsRaw), sessionsRaw, referenceRows);
 }
 
+function _attachProjectQuickCreateButton(chip, project){
+  const btn=document.createElement('button');
+  btn.type='button';
+  btn.className='project-chip-quick-create';
+  btn.textContent='+';
+  btn.title='New conversation in this project';
+  const stop=function(e){
+    if(!e) return;
+    if(typeof e.preventDefault==='function') e.preventDefault();
+    if(typeof e.stopPropagation==='function') e.stopPropagation();
+    if(typeof e.stopImmediatePropagation==='function') e.stopImmediatePropagation();
+  };
+  btn.onclick=(e)=>{
+    stop(e);
+    _setActiveProjectFilter(project.project_id);
+    void newSession(false,{project_id:project.project_id});
+  };
+  btn.ondblclick=(e)=>{stop(e);};
+  btn.oncontextmenu=(e)=>{stop(e);};
+  chip.appendChild(btn);
+}
+
 
 function renderSessionListFromCache(){
   // #4671: while a profile-switch skeleton is up, bail — _allSessions still holds the
@@ -6358,6 +6384,7 @@ function renderSessionListFromCache(){
         clearTimeout(_lpTimer);_lpTimer=null;_lpHandled=false;
         chip.classList.remove('long-pressing');
       },{passive:true});
+      _attachProjectQuickCreateButton(chip,p);
       bar.appendChild(chip);
     }
     // Create button
diff --git a/static/style.css b/static/style.css
index cd976b27..3cc235c2 100644
--- a/static/style.css
+++ b/static/style.css
@@ -5358,6 +5358,47 @@ main.main > #mainPlugin{display:none;}
 .project-chip:hover{background:rgba(255,255,255,.08);color:var(--text);}
 .project-chip.active{background:var(--accent-bg);color:var(--accent-text);border-color:var(--accent-bg);}
 .project-chip.long-pressing{background:var(--accent-bg);color:var(--accent-text);border-color:var(--accent-bg-strong);transform:scale(1.05);}
+.project-chip-quick-create{
+  border:1px solid transparent;
+  border-radius:999px;
+  min-width:16px;
+  min-height:16px;
+  padding:0 4px;
+  font-size:11px;
+  line-height:1;
+  font-weight:700;
+  display:inline-flex;
+  align-items:center;
+  justify-content:center;
+  color:var(--muted);
+  background:transparent;
+  opacity:0;
+  transition:opacity .15s,color .15s,background .15s,border-color .15s,transform .12s;
+}
+.project-chip:hover .project-chip-quick-create,
+.project-chip:focus-within .project-chip-quick-create{
+  opacity:1;
+  color:var(--text);
+  border-color:var(--border2);
+}
+.project-chip-quick-create:hover{
+  opacity:1;
+  color:var(--blue);
+  border-color:var(--blue);
+  background:rgba(255,255,255,.08);
+}
+@media (hover:none) and (pointer:coarse){
+  .project-chip-quick-create{
+    opacity:.72;
+    min-width:18px;
+    min-height:18px;
+    padding:0 6px;
+  }
+  .project-chip:hover .project-chip-quick-create,
+  .project-chip:focus-within .project-chip-quick-create{
+    opacity:1;
+  }
+}
 /* "Unassigned" filter chip — dashed border distinguishes it from real
    project chips so it reads as a meta-filter ("things without a project")
    rather than another project. Keeps full color treatment in the active
diff --git a/tests/test_4676_project_new_session_shortcuts.py b/tests/test_4676_project_new_session_shortcuts.py
new file mode 100644
index 00000000..639a81b7
--- /dev/null
+++ b/tests/test_4676_project_new_session_shortcuts.py
@@ -0,0 +1,312 @@
+"""Regression coverage for #4676: project-scope quick conversation creation."""
+
+import json
+import shutil
+import subprocess
+from pathlib import Path
+
+import pytest
+
+
+ROOT = Path(__file__).resolve().parents[1]
+SESSIONS_JS = ROOT / "static" / "sessions.js"
+STYLE_CSS = ROOT / "static" / "style.css"
+NODE = shutil.which("node")
+
+
+def _read(path: Path) -> str:
+    return path.read_text(encoding="utf-8")
+
+
+def _extract_function(source: str, name: str) -> str:
+    marker = f"function {name}("
+    start = source.find(marker)
+    assert start >= 0, f"{name} function not found in static/sessions.js"
+    brace = source.find("{", start)
+    assert brace >= 0, f"{name} declaration has no opening brace"
+    depth = 0
+    for idx in range(brace, len(source)):
+        ch = source[idx]
+        if ch == "{":
+            depth += 1
+        elif ch == "}":
+            depth -= 1
+            if depth == 0:
+                return source[start : idx + 1]
+    raise AssertionError(f"{name} function body not closed")
+
+
+def test_new_session_uses_explicit_project_override_before_active_filter():
+    src = _read(SESSIONS_JS)
+    assert "Object.prototype.hasOwnProperty.call(options,'project_id')" in src
+    assert "reqBody.project_id=options.project_id" in src
+
+
+def test_quick_create_button_attaches_filter_align_and_request_path():
+    src = _read(SESSIONS_JS)
+    helper = _extract_function(src, "_attachProjectQuickCreateButton")
+    assert "project-chip-quick-create" in helper
+    assert "_setActiveProjectFilter(project.project_id)" in helper
+    assert "newSession(false,{project_id:project.project_id})" in helper
+    assert "btn.ondblclick" in helper
+    assert "btn.oncontextmenu" in helper
+
+
+def test_project_quick_create_styles_exist_and_are_discrete_to_pointer_layouts():
+    css = _read(STYLE_CSS)
+    assert ".project-chip-quick-create" in css
+    assert ".project-chip:hover .project-chip-quick-create" in css
+    assert ".project-chip:focus-within .project-chip-quick-create" in css
+    assert ".project-chip-quick-create:hover" in css
+    assert "@media (hover:none) and (pointer:coarse)" in css
+
+
+def _run_new_session_case(options, active_project=None):
+    src = _read(SESSIONS_JS)
+
+    _DRIVER = r"""
+const fs = require('fs');
+const path = process.argv[1];
+const args = JSON.parse(process.argv[2]);
+const src = fs.readFileSync(path, 'utf8');
+
+function extractAsyncFunction(source, name) {
+  const marker = `async function ${name}(`;
+  const start = source.indexOf(marker);
+  if (start < 0) throw new Error(name + ' not found');
+  const brace = source.indexOf('{', source.indexOf(')', start));
+  let depth = 0;
+  for (let i = brace; i < source.length; i++) {
+    if (source[i] === '{') depth += 1;
+    else if (source[i] === '}') {
+      depth -= 1;
+      if (depth === 0) return source.slice(start, i + 1);
+    }
+  }
+  throw new Error('function body not closed for ' + name);
+}
+
+const newSessionSrc = extractAsyncFunction(src, 'newSession');
+
+globalThis.window = globalThis;
+globalThis.document = {
+  baseURI: 'http://example.test/',
+  createElement(tag) {
+    const node = {
+      tagName: String(tag || '').toUpperCase(),
+      children: [],
+      appendChild(child) { this.children.push(child); },
+      textContent: '',
+      value: '',
+      selectedOptions: [{ dataset: { provider: '' } }],
+      dataset: {},
+    };
+    return node;
+  },
+};
+globalThis.localStorage = { getItem: () => null, setItem: () => {} };
+globalThis.history = { replaceState: () => {} };
+globalThis.NO_PROJECT_FILTER = '__none__';
+globalThis._activeProject = args.activeProject;
+globalThis._sessionSourceFilter = 'webui';
+globalThis._newSessionInFlight = null;
+globalThis._messagesTruncated = false;
+globalThis._oldestIdx = 0;
+globalThis.INFLIGHT = {};
+globalThis.S = {
+  session: args.session || null,
+  toolCalls: [],
+  messages: [],
+  activeProfile: 'default',
+  _pendingSessionToolsets: null,
+  _profileSwitchWorkspace: null,
+  _profileDefaultWorkspace: null,
+};
+globalThis._defaultModel = null;
+globalThis._activeProvider = 'openai';
+globalThis._emptyComposerModelOverride = null;
+globalThis._readPersistedModelState = () => null;
+globalThis._readEmptyComposerModelOverride = () => null;
+globalThis._clearEmptyComposerModelOverride = () => {};
+globalThis.$ = (id) => (id === 'modelSelect' ? { value: 'gpt-4', selectedOptions: [{ dataset: { provider: 'openai' } }] } : null);
+for (const name of [
+  '_setNewSessionPending', 'updateQueueBadge', '_clearPendingSelections',
+  'clearLiveToolCards', 'setComposerStatus', 'setStatus', 'updateSendBtn',
+  'syncTopbar', 'renderMessages', 'startSessionStream', '_setSessionViewedCount',
+  '_setActiveSessionUrl', '_rememberNewChatDraftSession', '_hydrateTodosFromSession',
+  '_setLiveAssistantTps', '_syncCtxIndicator', 'showToast'
+]) {
+  globalThis[name] = () => {};
+}
+globalThis.loadDir = async () => null;
+globalThis._applyModelToDropdown = () => true;
+globalThis._modelStateForSelect = () => ({ model: 'gpt-4', model_provider: 'openai' });
+globalThis._readPersistedModelState = () => null;
+globalThis.getModelLabel = (v) => v || '';
+globalThis._defaultModel = null;
+
+const calls = [];
+globalThis.api = async (_url, opts) => {
+  calls.push(JSON.parse(opts.body));
+  return { session: { session_id: 's-1', messages: [], model: 'gpt-4', model_provider: 'openai', workspace: null, message_count: 0, last_usage: {} } };
+};
+
+eval(newSessionSrc);
+
+(async () => {
+  await newSession(false, args.options);
+  console.log(JSON.stringify({ body: calls[0] || {} }));
+})().catch(err => {
+  console.error(String(err && err.stack ? err.stack : err));
+  process.exit(1);
+});
+"""
+
+    payload = {
+        "activeProject": active_project,
+        "options": options,
+        "session": {"session_id": "session-1"},
+    }
+    result = subprocess.run(
+        [NODE, "-e", _DRIVER, str(SESSIONS_JS), json.dumps(payload)],
+        capture_output=True,
+        text=True,
+        timeout=30,
+        check=False,
+    )
+    if result.returncode != 0:
+        raise RuntimeError(
+            f"node driver failed:\nSTDOUT={result.stdout}\nSTDERR={result.stderr}"
+        )
+    return json.loads(result.stdout.strip().splitlines()[-1])["body"]
+
+
+@pytest.mark.skipif(NODE is None, reason="node not on PATH")
+def test_new_session_aligns_project_id_override_when_explicitly_set():
+    body = _run_new_session_case({"project_id": "explicit-project"}, active_project="active-project")
+    assert body["project_id"] == "explicit-project"
+
+
+@pytest.mark.skipif(NODE is None, reason="node not on PATH")
+def test_new_session_respects_explicit_project_id_none():
+    body = _run_new_session_case({"project_id": None}, active_project="active-project")
+    assert "project_id" in body
+    assert body["project_id"] is None
+
+
+@pytest.mark.skipif(NODE is None, reason="node not on PATH")
+def test_new_session_falls_back_to_active_project_when_override_missing():
+    body = _run_new_session_case({}, active_project="active-project")
+    assert body["project_id"] == "active-project"
+
+
+_HELPER = r"""
+const fs = require('fs');
+const sessionsSrc = fs.readFileSync(process.argv[1], 'utf8');
+const params = JSON.parse(process.argv[2]);
+
+function extractFunction(source, name) {
+  const marker = `function ${name}(`;
+  const start = source.indexOf(marker);
+  if (start < 0) throw new Error(name + ' not found');
+  const brace = source.indexOf('{', start);
+  let depth = 0;
+  for (let i = brace; i < source.length; i++) {
+    if (source[i] === '{') depth++;
+    else if (source[i] === '}') {
+      depth--;
+      if (depth === 0) return source.slice(start, i + 1);
+    }
+  }
+  throw new Error('function body not closed for ' + name);
+}
+
+globalThis.window = globalThis;
+globalThis.document = {
+  createElement(tag) {
+    return {
+      tagName: String(tag || '').toUpperCase(),
+      className: '',
+      textContent: '',
+      children: [],
+      appendChild(child) { this.children.push(child); },
+      appendChildCallCount: 0,
+      dataset: {},
+      type: '',
+    };
+  },
+};
+globalThis._setActiveProjectFilter = (projectId) => {
+  params.filterProjectId = projectId;
+  params.calls.push({type: 'set-filter', projectId});
+};
+globalThis.newSession = async (flash, options) => {
+  params.newSession = {flash, options};
+  params.calls.push({type: 'new-session', flash, options});
+};
+
+eval(extractFunction(sessionsSrc, '_attachProjectQuickCreateButton'));
+
+const chip = {
+  appended: [],
+  appendChild(child) { this.appended.push(child); },
+};
+_attachProjectQuickCreateButton(chip, { project_id: params.projectId });
+const btn = chip.appended[0];
+const ev = {
+  stopPropagation() { params.stopCount++; },
+  preventDefault() { params.preventCount++; },
+  stopImmediatePropagation() { params.stopImmediateCount++; },
+};
+btn.onclick(ev);
+btn.ondblclick(ev);
+btn.oncontextmenu(ev);
+console.log(JSON.stringify({
+  buttonClass: btn.className,
+  buttonTag: btn.tagName,
+  buttonText: btn.textContent,
+  newSession: params.newSession,
+  filterProjectId: params.filterProjectId,
+  stopCount: params.stopCount,
+  preventCount: params.preventCount,
+  stopImmediateCount: params.stopImmediateCount,
+  calls: params.calls,
+}));
+"""
+
+
+def _run_quick_create_case(project_id="example-project"):
+    payload = {
+        "projectId": project_id,
+        "calls": [],
+        "stopCount": 0,
+        "preventCount": 0,
+        "stopImmediateCount": 0,
+    }
+    result = subprocess.run(
+        [NODE, "-e", _HELPER, str(SESSIONS_JS), json.dumps(payload)],
+        capture_output=True,
+        text=True,
+        timeout=30,
+        check=False,
+    )
+    if result.returncode != 0:
+        raise RuntimeError(
+            f"node helper failed:\nSTDOUT={result.stdout}\nSTDERR={result.stderr}"
+        )
+    return json.loads(result.stdout.strip().splitlines()[-1])
+
+
+@pytest.mark.skipif(NODE is None, reason="node not on PATH")
+def test_project_chip_quick_create_keeps_active_filter_and_uses_project_override():
+    out = _run_quick_create_case("project-123")
+    assert out["buttonClass"] == "project-chip-quick-create"
+    assert out["buttonTag"] == "BUTTON"
+    assert out["buttonText"] == "+"
+    assert out["filterProjectId"] == "project-123"
+    assert out["newSession"] == {"flash": False, "options": {"project_id": "project-123"}}
+    assert {"type": "set-filter", "projectId": "project-123"} in out["calls"]
+    assert {"type": "new-session", "flash": False, "options": {"project_id": "project-123"}} in out["calls"]
+    assert out["stopCount"] >= 3
+    assert out["preventCount"] >= 3
+    assert out["stopImmediateCount"] >= 3