diff --git a/src/hooks/anthropic-context-window-limit-recovery/parser.test.ts b/src/hooks/anthropic-context-window-limit-recovery/parser.test.ts
new file mode 100644
index 000000000..d0fa10584
--- /dev/null
+++ b/src/hooks/anthropic-context-window-limit-recovery/parser.test.ts
@@ -0,0 +1,97 @@
+/// <reference types="bun-types" />
+import { describe, expect, it } from "bun:test"
+import { parseAnthropicTokenLimitError } from "./parser"
+
+describe("parseAnthropicTokenLimitError", () => {
+  it("#given a standard token limit error string #when parsing #then extracts tokens", () => {
+    //#given
+    const error = "prompt is too long: 250000 tokens > 200000 maximum"
+
+    //#when
+    const result = parseAnthropicTokenLimitError(error)
+
+    //#then
+    expect(result).not.toBeNull()
+    expect(result!.currentTokens).toBe(250000)
+    expect(result!.maxTokens).toBe(200000)
+  })
+
+  it("#given a non-token-limit error #when parsing #then returns null", () => {
+    //#given
+    const error = { message: "internal server error" }
+
+    //#when
+    const result = parseAnthropicTokenLimitError(error)
+
+    //#then
+    expect(result).toBeNull()
+  })
+
+  it("#given null input #when parsing #then returns null", () => {
+    //#given
+    const error = null
+
+    //#when
+    const result = parseAnthropicTokenLimitError(error)
+
+    //#then
+    expect(result).toBeNull()
+  })
+
+  it("#given a proxy error with non-standard structure #when parsing #then returns null without crashing", () => {
+    //#given
+    const proxyError = {
+      data: [1, 2, 3],
+      error: "string-not-object",
+      message: "Failed to process error response",
+    }
+
+    //#when
+    const result = parseAnthropicTokenLimitError(proxyError)
+
+    //#then
+    expect(result).toBeNull()
+  })
+
+  it("#given a circular reference error #when parsing #then returns null without crashing", () => {
+    //#given
+    const circular: Record<string, unknown> = { message: "prompt is too long" }
+    circular.self = circular
+
+    //#when
+    const result = parseAnthropicTokenLimitError(circular)
+
+    //#then
+    expect(result).not.toBeNull()
+  })
+
+  it("#given an error where data.responseBody has invalid JSON #when parsing #then handles gracefully", () => {
+    //#given
+    const error = {
+      data: { responseBody: "not valid json {{{" },
+      message: "prompt is too long with 300000 tokens exceeds 200000",
+    }
+
+    //#when
+    const result = parseAnthropicTokenLimitError(error)
+
+    //#then
+    expect(result).not.toBeNull()
+    expect(result!.currentTokens).toBe(300000)
+    expect(result!.maxTokens).toBe(200000)
+  })
+
+  it("#given an error with data as a string (not object) #when parsing #then does not crash", () => {
+    //#given
+    const error = {
+      data: "some-string-data",
+      message: "token limit exceeded",
+    }
+
+    //#when
+    const result = parseAnthropicTokenLimitError(error)
+
+    //#then
+    expect(result).not.toBeNull()
+  })
+})
diff --git a/src/hooks/anthropic-context-window-limit-recovery/parser.ts b/src/hooks/anthropic-context-window-limit-recovery/parser.ts
index dda87bbd5..451d1ab18 100644
--- a/src/hooks/anthropic-context-window-limit-recovery/parser.ts
+++ b/src/hooks/anthropic-context-window-limit-recovery/parser.ts
@@ -74,6 +74,14 @@ function isTokenLimitError(text: string): boolean {
 }
 
 export function parseAnthropicTokenLimitError(err: unknown): ParsedTokenLimitError | null {
+  try {
+    return parseAnthropicTokenLimitErrorUnsafe(err)
+  } catch {
+    return null
+  }
+}
+
+function parseAnthropicTokenLimitErrorUnsafe(err: unknown): ParsedTokenLimitError | null {
   if (typeof err === "string") {
     if (err.toLowerCase().includes("non-empty content")) {
       return {