diff --git a/src/orchestrator/agent-loader.ts b/src/orchestrator/agent-loader.ts
index 96130b7..147c185 100644
--- a/src/orchestrator/agent-loader.ts
+++ b/src/orchestrator/agent-loader.ts
@@ -210,7 +210,7 @@ export async function assembleSystemPrompt(
     const env = await detectEnvironment(projectRoot);
     const toolNames =
       ROLE_TOOLS[role as keyof typeof ROLE_TOOLS] ?? [];
-    return `${decorated}\n\n${formatEnvironmentContext(env, [...toolNames])}`;
+    return `${decorated}\n\n${formatEnvironmentContext(env, [...toolNames], projectRoot)}`;
   } catch {
     // Environment detection is best-effort — never block agent spawn.
     return decorated;
diff --git a/src/orchestrator/environment.test.ts b/src/orchestrator/environment.test.ts
new file mode 100644
index 0000000..ce2435e
--- /dev/null
+++ b/src/orchestrator/environment.test.ts
@@ -0,0 +1,53 @@
+/**
+ * Unit tests for formatEnvironmentContext — the markdown block injected into
+ * agent system prompts. Focus on the project-root + relative-path guidance
+ * added to stop non-Claude models inventing absolute paths.
+ */
+
+import { describe, it, expect } from "vitest";
+
+import { formatEnvironmentContext, type HostEnvironment } from "./environment.js";
+
+const ENV: HostEnvironment = {
+  platform: "darwin",
+  osName: "macOS",
+  osRelease: "25.2.0",
+  arch: "arm64",
+  shell: "/bin/zsh",
+  nodeVersion: "v22.14.0",
+  packageManager: "npm",
+  installedTools: ["git", "node", "npm"],
+};
+
+const ROOT = "/Users/bober4ik/agent-bober-workspace/agent-bober-ide";
+
+describe("formatEnvironmentContext", () => {
+  it("surfaces the absolute project root when provided", () => {
+    const out = formatEnvironmentContext(ENV, ["read_file", "glob"], ROOT);
+    expect(out).toContain(`- Project root (absolute): ${ROOT}`);
+  });
+
+  it("omits the project-root line when not provided", () => {
+    const out = formatEnvironmentContext(ENV, ["read_file", "glob"]);
+    expect(out).not.toContain("Project root (absolute)");
+  });
+
+  it("adds relative-path guidance when a path-bearing tool is present", () => {
+    const out = formatEnvironmentContext(ENV, ["glob", "grep"], ROOT);
+    expect(out).toContain("pass paths RELATIVE to the project root");
+    expect(out).toContain("Do NOT construct absolute");
+  });
+
+  it("omits relative-path guidance when no path tool is available", () => {
+    const out = formatEnvironmentContext(ENV, ["report"], ROOT);
+    expect(out).not.toContain("pass paths RELATIVE to the project root");
+  });
+
+  it("still lists the exact tools and host OS", () => {
+    const out = formatEnvironmentContext(ENV, ["read_file", "glob"], ROOT);
+    expect(out).toContain("# Host Environment");
+    expect(out).toContain("- OS: macOS (darwin 25.2.0, arm64)");
+    expect(out).toContain("# Your Tools");
+    expect(out).toContain("You have EXACTLY these tools: read_file, glob.");
+  });
+});
diff --git a/src/orchestrator/environment.ts b/src/orchestrator/environment.ts
index afcfa72..a3f3ede 100644
--- a/src/orchestrator/environment.ts
+++ b/src/orchestrator/environment.ts
@@ -139,14 +139,18 @@ export function resetEnvironmentCache(): void {
  * Render the environment + the role's exact harness tools as a markdown block
  * for injection into an agent's system prompt.
  *
- * @param env       Detected host environment.
- * @param toolNames The exact harness tool names available to this role (e.g.
- *                  ["read_file","glob","grep"]). Used to stop models inventing
- *                  tools (e.g. a non-existent "bash" for read-only roles).
+ * @param env         Detected host environment.
+ * @param toolNames   The exact harness tool names available to this role (e.g.
+ *                    ["read_file","glob","grep"]). Used to stop models inventing
+ *                    tools (e.g. a non-existent "bash" for read-only roles).
+ * @param projectRoot Absolute path to the project root. Surfaced so models stop
+ *                    guessing it — non-Claude models otherwise invent an absolute
+ *                    path with the wrong home dir, which the path sandbox rejects.
  */
 export function formatEnvironmentContext(
   env: HostEnvironment,
   toolNames: string[],
+  projectRoot?: string,
 ): string {
   const lines: string[] = [];
   lines.push("# Host Environment");
@@ -157,6 +161,7 @@ export function formatEnvironmentContext(
   lines.push(`- Node: ${env.nodeVersion}`);
   if (env.packageManager)
     lines.push(`- Package manager: ${env.packageManager}`);
+  if (projectRoot) lines.push(`- Project root (absolute): ${projectRoot}`);
   if (env.installedTools.length > 0) {
     lines.push(`- Installed CLIs on PATH: ${env.installedTools.join(", ")}`);
   }
@@ -180,5 +185,18 @@ export function formatEnvironmentContext(
       `state that in your output rather than inventing a tool.`,
   );
 
+  const hasPathTool = toolNames.some((t) =>
+    ["read_file", "write_file", "edit_file", "glob", "grep"].includes(t),
+  );
+  if (hasPathTool) {
+    lines.push(
+      "",
+      "For file/path tool arguments, pass paths RELATIVE to the project root " +
+        "(e.g. `src`, `src/index.ts`, `src/**/*.ts`). Do NOT construct absolute " +
+        "paths — you do not know the real home directory and a wrong guess is " +
+        "rejected by the path sandbox.",
+    );
+  }
+
   return lines.join("\n");
 }
diff --git a/src/orchestrator/tools/handlers.test.ts b/src/orchestrator/tools/handlers.test.ts
new file mode 100644
index 0000000..eb4327a
--- /dev/null
+++ b/src/orchestrator/tools/handlers.test.ts
@@ -0,0 +1,76 @@
+/**
+ * Unit tests for sandboxPath — the path-sandboxing guard shared by the
+ * read_file / write_file / edit_file / glob / grep tool handlers.
+ *
+ * Focus: the re-anchoring recovery for absolute paths invented with the wrong
+ * home directory (the DeepSeek `/Users/boberik/...` failure mode), without
+ * widening the sandbox for genuinely-foreign paths.
+ */
+
+import { describe, it, expect } from "vitest";
+import { resolve } from "node:path";
+
+import { sandboxPath } from "./handlers.js";
+
+const ROOT = "/Users/bober4ik/agent-bober-workspace/agent-bober-ide";
+
+describe("sandboxPath", () => {
+  it("accepts a relative path and resolves it under the root", () => {
+    expect(sandboxPath(ROOT, "src")).toBe(resolve(ROOT, "src"));
+    expect(sandboxPath(ROOT, "src/index.ts")).toBe(
+      resolve(ROOT, "src/index.ts"),
+    );
+  });
+
+  it("accepts the root itself (empty relative path)", () => {
+    expect(sandboxPath(ROOT, ".")).toBe(resolve(ROOT));
+    expect(sandboxPath(ROOT, ROOT)).toBe(resolve(ROOT));
+  });
+
+  it("accepts a correct absolute path inside the root", () => {
+    const abs = `${ROOT}/src/app.ts`;
+    expect(sandboxPath(ROOT, abs)).toBe(resolve(abs));
+  });
+
+  it("re-anchors an absolute path invented with the wrong home dir", () => {
+    // DeepSeek hallucinated `boberik` instead of the real `bober4ik`.
+    const bogus =
+      "/Users/boberik/agent-bober-workspace/agent-bober-ide/src";
+    expect(sandboxPath(ROOT, bogus)).toBe(resolve(ROOT, "src"));
+  });
+
+  it("re-anchors a deep wrong-home absolute path to the right suffix", () => {
+    const bogus =
+      "/home/ci/agent-bober-ide/src/components/Button.tsx";
+    expect(sandboxPath(ROOT, bogus)).toBe(
+      resolve(ROOT, "src/components/Button.tsx"),
+    );
+  });
+
+  it("re-anchors a wrong-home path that points at the root itself", () => {
+    const bogus = "/Users/boberik/agent-bober-workspace/agent-bober-ide";
+    expect(sandboxPath(ROOT, bogus)).toBe(resolve(ROOT));
+  });
+
+  it("still blocks a relative traversal escaping the root", () => {
+    expect(() => sandboxPath(ROOT, "../../etc/passwd")).toThrow(
+      /outside the project root/,
+    );
+  });
+
+  it("still blocks a genuinely-foreign absolute path (no root basename)", () => {
+    expect(() => sandboxPath(ROOT, "/etc/passwd")).toThrow(
+      /outside the project root/,
+    );
+  });
+
+  it("re-anchoring never widens the sandbox: suffix stays inside root", () => {
+    // Even a malicious suffix after the root name cannot escape, because the
+    // re-anchored path is re-validated against the root.
+    const sneaky =
+      "/Users/attacker/agent-bober-ide/../../../../etc/passwd";
+    expect(() => sandboxPath(ROOT, sneaky)).toThrow(
+      /outside the project root/,
+    );
+  });
+});
diff --git a/src/orchestrator/tools/handlers.ts b/src/orchestrator/tools/handlers.ts
index 93ca67b..9da6134 100644
--- a/src/orchestrator/tools/handlers.ts
+++ b/src/orchestrator/tools/handlers.ts
@@ -1,5 +1,5 @@
 import { readFile, writeFile, mkdir } from "node:fs/promises";
-import { resolve, relative, isAbsolute } from "node:path";
+import { resolve, relative, isAbsolute, basename, sep } from "node:path";
 import { execa } from "execa";
 
 // ── Constants ──────────────────────────────────────────────────────
@@ -27,14 +27,41 @@ export type ToolHandler = (
 /**
  * Resolve and validate a file path, ensuring it stays within projectRoot.
  * Returns the absolute path or throws if the path escapes the sandbox.
+ *
+ * Re-anchoring recovery: non-Claude models (e.g. DeepSeek) sometimes ignore the
+ * "relative to project root" contract and invent an ABSOLUTE path with the wrong
+ * home dir — e.g. `/Users/boberik/.../agent-bober-ide/src` when the real root is
+ * `/Users/bober4ik/.../agent-bober-ide`. When such a path lands outside the root
+ * but still contains the root's basename, we re-anchor the suffix after it
+ * (`src`) relative to the real root and retry. This NEVER widens the sandbox: the
+ * re-anchored path is `resolve(projectRoot, suffix)` and is re-validated to be
+ * inside the root before use, so a genuinely-foreign path still fails closed.
  */
-function sandboxPath(projectRoot: string, inputPath: string): string {
-  const abs = isAbsolute(inputPath)
+export function sandboxPath(projectRoot: string, inputPath: string): string {
+  let abs = isAbsolute(inputPath)
     ? resolve(inputPath)
     : resolve(projectRoot, inputPath);
 
+  let rel = relative(projectRoot, abs);
+
+  if ((rel.startsWith("..") || isAbsolute(rel)) && isAbsolute(inputPath)) {
+    const rootName = basename(projectRoot);
+    if (rootName) {
+      const segments = abs.split(sep);
+      const idx = segments.lastIndexOf(rootName);
+      if (idx !== -1) {
+        const suffix = segments.slice(idx + 1).join(sep);
+        const reAnchored = resolve(projectRoot, suffix);
+        const reRel = relative(projectRoot, reAnchored);
+        if (!reRel.startsWith("..") && !isAbsolute(reRel)) {
+          abs = reAnchored;
+          rel = reRel;
+        }
+      }
+    }
+  }
+
   // Ensure the resolved path is within the project root
-  const rel = relative(projectRoot, abs);
   if (rel.startsWith("..") || isAbsolute(rel)) {
     throw new Error(
       `Path "${inputPath}" resolves outside the project root. Access denied.`,
diff --git a/src/orchestrator/tools/schemas.ts b/src/orchestrator/tools/schemas.ts
index bc808ea..1dfe6c0 100644
--- a/src/orchestrator/tools/schemas.ts
+++ b/src/orchestrator/tools/schemas.ts
@@ -37,7 +37,7 @@ export const readFileTool: ToolDef = {
       file_path: {
         type: "string",
         description:
-          "Path to the file, relative to the project root or absolute.",
+          "Path to the file, relative to the project root (e.g. `src/index.ts`). Pass a relative path, not an absolute one.",
       },
       offset: {
         type: "number",
@@ -62,7 +62,7 @@ export const writeFileTool: ToolDef = {
       file_path: {
         type: "string",
         description:
-          "Path to the file, relative to the project root or absolute.",
+          "Path to the file, relative to the project root (e.g. `src/index.ts`). Pass a relative path, not an absolute one.",
       },
       content: {
         type: "string",
@@ -83,7 +83,7 @@ export const editFileTool: ToolDef = {
       file_path: {
         type: "string",
         description:
-          "Path to the file, relative to the project root or absolute.",
+          "Path to the file, relative to the project root (e.g. `src/index.ts`). Pass a relative path, not an absolute one.",
       },
       old_text: {
         type: "string",
@@ -113,7 +113,7 @@ export const globTool: ToolDef = {
       path: {
         type: "string",
         description:
-          "Directory to search in, relative to project root. Defaults to project root.",
+          "Directory to search in, relative to project root (e.g. `src`). Pass a relative path, not an absolute one. Defaults to project root.",
       },
     },
     required: ["pattern"],
@@ -134,7 +134,7 @@ export const grepTool: ToolDef = {
       path: {
         type: "string",
         description:
-          "File or directory to search in, relative to project root. Defaults to project root.",
+          "File or directory to search in, relative to project root (e.g. `src`). Pass a relative path, not an absolute one. Defaults to project root.",
       },
       glob: {
         type: "string",