diff --git a/.env.example b/.env.example
index a792e87..bd32787 100644
--- a/.env.example
+++ b/.env.example
@@ -3,5 +3,6 @@ PORT=3000
 DATABASE_URL=postgres://boocode:CHANGE_ME@boocode_db:5432/boocode
 LLAMA_SWAP_URL=http://100.101.41.16:8401
 PROJECT_ROOT_WHITELIST=/opt
+BOOTSTRAP_ROOT=/opt/projects
 DEFAULT_MODEL=qwen3.6-35b-a3b-mxfp4
 POSTGRES_PASSWORD=CHANGE_ME
diff --git a/CLAUDE.md b/CLAUDE.md
index 6f0fd5c..6fc5049 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -88,7 +88,7 @@ Position-shift pattern for panes (legacy `session_panes` table): negate-and-rest
 
 ## Environment
 
-Required: `DATABASE_URL`, `LLAMA_SWAP_URL`. Optional: `PORT` (3000), `HOST` (0.0.0.0), `PROJECT_ROOT_WHITELIST` (/opt), `DEFAULT_MODEL`, `LOG_LEVEL`.
+Required: `DATABASE_URL`, `LLAMA_SWAP_URL`. Optional: `PORT` (3000), `HOST` (0.0.0.0), `PROJECT_ROOT_WHITELIST` (/opt, read-only scope for add-existing path resolution), `BOOTSTRAP_ROOT` (/opt/projects, writable scope for create-new-project bootstrap mkdir target — host must `mkdir -p /opt/projects` before container start), `DEFAULT_MODEL`, `LOG_LEVEL`.
 
 ## Workflow
 
diff --git a/apps/server/src/config.ts b/apps/server/src/config.ts
index bc30e48..5350741 100644
--- a/apps/server/src/config.ts
+++ b/apps/server/src/config.ts
@@ -7,6 +7,7 @@ const ConfigSchema = z.object({
   DATABASE_URL: z.string().url(),
   LLAMA_SWAP_URL: z.string().url(),
   PROJECT_ROOT_WHITELIST: z.string().default('/opt'),
+  BOOTSTRAP_ROOT: z.string().default('/opt/projects'),
   DEFAULT_MODEL: z.string().default('qwen3.6-35b-a3b-mxfp4'),
   LOG_LEVEL: z.string().default('info'),
   GITEA_BASE_URL: z.string().url().default('https://git.indifferentketchup.com'),
diff --git a/apps/server/src/services/project_bootstrap.ts b/apps/server/src/services/project_bootstrap.ts
index 7762ce3..c080549 100644
--- a/apps/server/src/services/project_bootstrap.ts
+++ b/apps/server/src/services/project_bootstrap.ts
@@ -82,11 +82,13 @@ export async function bootstrapProject(
     throw new BootstrapNameError(`invalid name after sanitization: "${folder}"`);
   }
 
-  // Whitelist resolution
-  const whitelistReal = await realpath(config.PROJECT_ROOT_WHITELIST);
-  const fullPath = resolve(whitelistReal, folder);
-  if (!fullPath.startsWith(whitelistReal + sep)) {
-    throw new BootstrapPathError('path escapes whitelist');
+  // Bootstrap target resolution. Uses BOOTSTRAP_ROOT (writable), not
+  // PROJECT_ROOT_WHITELIST (which may be a wider read-only scope for
+  // add-existing flow).
+  const bootstrapReal = await realpath(config.BOOTSTRAP_ROOT);
+  const fullPath = resolve(bootstrapReal, folder);
+  if (!fullPath.startsWith(bootstrapReal + sep)) {
+    throw new BootstrapPathError('path escapes bootstrap root');
   }
   if (existsSync(fullPath)) {
     throw new BootstrapCollisionError(`path already exists: ${fullPath}`);
diff --git a/docker-compose.yml b/docker-compose.yml
index 2ca91e7..45dd681 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -9,7 +9,11 @@ services:
     environment:
       DATABASE_URL: postgres://boocode:${POSTGRES_PASSWORD}@boocode_db:5432/boocode
     volumes:
-      - /opt:/opt:rw
+      # Read-only mount for legacy/existing project add-existing flow.
+      - /opt:/opt:ro
+      # Writable mount only for the create-new-project bootstrap target.
+      # Host must `mkdir -p /opt/projects` before container start.
+      - /opt/projects:/opt/projects:rw
     depends_on:
       - boocode_db
     networks: