Merge pull request #66 from langchain-ai/dqbd/read-raw-filesystem-backend

feat: add readRaw method to filesystem backend protocol

Author: dqbd

.changeset/young-papers-thank.md

@@ -0,0 +1,5 @@
+---
+"deepagents": minor
+---
+
+Add readRaw method to filesystem backend protocol

examples/backends/store-backend.ts

@@ -65,16 +65,12 @@ export const agent = createDeepAgent({
 async function main() {
   const threadId = uuidv4();
 
+  const message = new HumanMessage(
+    "Research the latest trends in AI agents for 2025",
+  );
   await agent.invoke(
-    {
-      messages: [
-        new HumanMessage("Research the latest trends in AI agents for 2025"),
-      ],
-    },
-    {
-      recursionLimit: 50,
-      configurable: { thread_id: threadId },
-    },
+    { messages: [message] },
+    { recursionLimit: 50, configurable: { thread_id: threadId } },
   );
 
   const threadId2 = uuidv4();

examples/research/research-agent.ts

@@ -202,6 +202,7 @@ export const agent = createDeepAgent({
     model: "claude-sonnet-4-20250514",
     temperature: 0,
   }),
+
   tools: [internetSearch],
   systemPrompt: researchInstructions,
   subagents: [critiqueSubAgent, researchSubAgent],

package.json

@@ -52,9 +52,9 @@
     "@changesets/cli": "^2.29.7",
     "@eslint/eslintrc": "^3.1.0",
     "@eslint/js": "^9.19.0",
-    "@langchain/langgraph-checkpoint": "^0.0.13",
+    "@langchain/langgraph-checkpoint": "^1.0.0",
     "@langchain/openai": "^1.0.0",
-    "@langchain/tavily": "^0.1.4",
+    "@langchain/tavily": "^1.0.0",
     "@tsconfig/recommended": "^1.0.10",
     "@types/micromatch": "^4.0.10",
     "@types/node": "^22.13.5",

pnpm-lock.yaml

@@ -5,6 +5,7 @@
 import type {
   BackendProtocol,
   EditResult,
+  FileData,
   FileInfo,
   GrepMatch,
   WriteResult,
@@ -128,6 +129,17 @@ export class CompositeBackend implements BackendProtocol {
     return await backend.read(strippedKey, offset, limit);
   }
 
+  /**
+   * Read file content as raw FileData.
+   *
+   * @param filePath - Absolute file path
+   * @returns Raw file content as FileData
+   */
+  async readRaw(filePath: string): Promise<FileData> {
+    const [backend, strippedKey] = this.getBackendAndKey(filePath);
+    return await backend.readRaw(strippedKey);
+  }
+
   /**
    * Structured search results or error string for invalid input.
    */

src/backends/composite.ts

@@ -17,6 +17,7 @@ import micromatch from "micromatch";
 import type {
   BackendProtocol,
   EditResult,
+  FileData,
   FileInfo,
   GrepMatch,
   WriteResult,
@@ -241,6 +242,46 @@ export class FilesystemBackend implements BackendProtocol {
     }
   }
 
+  /**
+   * Read file content as raw FileData.
+   *
+   * @param filePath - Absolute file path
+   * @returns Raw file content as FileData
+   */
+  async readRaw(filePath: string): Promise<FileData> {
+    const resolvedPath = this.resolvePath(filePath);
+
+    let content: string;
+    let stat: fsSync.Stats;
+
+    if (SUPPORTS_NOFOLLOW) {
+      stat = await fs.stat(resolvedPath);
+      if (!stat.isFile()) throw new Error(`File '${filePath}' not found`);
+      const fd = await fs.open(
+        resolvedPath,
+        fsSync.constants.O_RDONLY | fsSync.constants.O_NOFOLLOW,
+      );
+      try {
+        content = await fd.readFile({ encoding: "utf-8" });
+      } finally {
+        await fd.close();
+      }
+    } else {
+      stat = await fs.lstat(resolvedPath);
+      if (stat.isSymbolicLink()) {
+        throw new Error(`Symlinks are not allowed: ${filePath}`);
+      }
+      if (!stat.isFile()) throw new Error(`File '${filePath}' not found`);
+      content = await fs.readFile(resolvedPath, "utf-8");
+    }
+
+    return {
+      content: content.split("\n"),
+      created_at: stat.ctime.toISOString(),
+      modified_at: stat.mtime.toISOString(),
+    };
+  }
+
   /**
    * Create a new file with content.
    * Returns WriteResult. External storage sets filesUpdate=null.

src/backends/filesystem.ts

@@ -128,6 +128,14 @@ export interface BackendProtocol {
     limit?: number,
   ): string | Promise<string>;
 
+  /**
+   * Read file content as raw FileData.
+   *
+   * @param filePath - Absolute file path
+   * @returns Raw file content as FileData
+   */
+  readRaw(filePath: string): FileData | Promise<FileData>;
+
   /**
    * Structured search results or error string for invalid input.
    *

src/backends/protocol.ts

@@ -124,6 +124,20 @@ export class StateBackend implements BackendProtocol {
     return formatReadResponse(fileData, offset, limit);
   }
 
+  /**
+   * Read file content as raw FileData.
+   *
+   * @param filePath - Absolute file path
+   * @returns Raw file content as FileData
+   */
+  readRaw(filePath: string): FileData {
+    const files = this.getFiles();
+    const fileData = files[filePath];
+
+    if (!fileData) throw new Error(`File '${filePath}' not found`);
+    return fileData;
+  }
+
   /**
    * Create a new file with content.
    * Returns WriteResult with filesUpdate to update LangGraph state.

src/backends/state.ts

@@ -238,22 +238,29 @@ export class StoreBackend implements BackendProtocol {
     offset: number = 0,
     limit: number = 2000,
   ): Promise<string> {
-    const store = this.getStore();
-    const namespace = this.getNamespace();
-    const item = await store.get(namespace, filePath);
-
-    if (!item) {
-      return `Error: File '${filePath}' not found`;
-    }
-
     try {
-      const fileData = this.convertStoreItemToFileData(item);
+      const fileData = await this.readRaw(filePath);
       return formatReadResponse(fileData, offset, limit);
     } catch (e: any) {
       return `Error: ${e.message}`;
     }
   }
 
+  /**
+   * Read file content as raw FileData.
+   *
+   * @param filePath - Absolute file path
+   * @returns Raw file content as FileData
+   */
+  async readRaw(filePath: string): Promise<FileData> {
+    const store = this.getStore();
+    const namespace = this.getNamespace();
+    const item = await store.get(namespace, filePath);
+
+    if (!item) throw new Error(`File '${filePath}' not found`);
+    return this.convertStoreItemToFileData(item);
+  }
+
   /**
    * Create a new file with content.
    * Returns WriteResult. External storage sets filesUpdate=null.