From 8b9336466f711626fb2c27e2a880d559102f3f88 Mon Sep 17 00:00:00 2001
From: Dayuan Jiang <34411969+DayuanJiang@users.noreply.github.com>
Date: Thu, 11 Dec 2025 14:14:31 +0900
Subject: [PATCH] feat: make PDF/text extraction char limit configurable via
 env (#214)

Add NEXT_PUBLIC_MAX_EXTRACTED_CHARS environment variable to allow
configuring the maximum characters extracted from PDF and text files.
Defaults to 150000 (150k chars) if not set.
---
 env.example      | 1 +
 lib/pdf-utils.ts | 7 +++++--
 2 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/env.example b/env.example
index 616243e..65dd428 100644
--- a/env.example
+++ b/env.example
@@ -90,3 +90,4 @@ AI_MODEL=global.anthropic.claude-sonnet-4-5-20250929-v1:0
 # Enable PDF file upload to extract text and generate diagrams
 # Enabled by default. Set to "false" to disable.
 # ENABLE_PDF_INPUT=true
+# NEXT_PUBLIC_MAX_EXTRACTED_CHARS=150000  # Max characters for PDF/text extraction (default: 150000)
diff --git a/lib/pdf-utils.ts b/lib/pdf-utils.ts
index b069cc4..2e5c4ad 100644
--- a/lib/pdf-utils.ts
+++ b/lib/pdf-utils.ts
@@ -1,7 +1,10 @@
 import { extractText, getDocumentProxy } from "unpdf"
 
-// Maximum characters allowed for extracted text
-export const MAX_EXTRACTED_CHARS = 150000 // 150k chars
+// Maximum characters allowed for extracted text (configurable via env)
+const DEFAULT_MAX_EXTRACTED_CHARS = 150000 // 150k chars
+export const MAX_EXTRACTED_CHARS =
+    Number(process.env.NEXT_PUBLIC_MAX_EXTRACTED_CHARS) ||
+    DEFAULT_MAX_EXTRACTED_CHARS
 
 // Text file extensions we support
 const TEXT_EXTENSIONS = [