diff --git a/CHANGELOG.md b/CHANGELOG.md
index f67890a..1c007e7 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,12 @@
 # Changelog
 
+## 0.4.0
+
+46 built-in definitions cover filesystem, permissions, networking, module loading, streams, HTTP response lifecycle and JavaScript errors. Each has a specific explanation, likely causes and practical checks. Rubber-duck commentary has a distinct original line for every supported definition. No commands run automatically and unknown errors remain explicitly unrecognized.
+
+```sh
+
+
 ## 0.3.0 — 2026-10-08
 
 - Useful structured API/CLI additions described in README.
@@ -22,3 +29,4 @@
 - Plain-English translations for ECONNREFUSED, ENOENT, EADDRINUSE, MODULE_NOT_FOUND, ERR_MODULE_NOT_FOUND, and TypeError.
 - Structured results, text rendering, and CLI with JSON output.
 - Automated tests, linting, formatting, and Node 22/24 CI.
+```
diff --git a/MIGRATION.md b/MIGRATION.md
index c14f761..5058fa7 100644
--- a/MIGRATION.md
+++ b/MIGRATION.md
@@ -3,3 +3,9 @@
 Node 22.13+ is required. Existing core APIs remain available; TypeScript declarations and CommonJS exports are new. The CLI now lives in src/cli.js behind the same executable path. Input/stdout behavior for new options is documented in README.
 
 Install 0.3.0 with npm. Seeds and exact humorous wording are version-specific. Do not treat jokes or heuristic scores as production evidence.
+
+## 0.3.0 to 0.4.0
+
+46 distinct error definitions with explanations, causes and practical checks; original duck commentary for each; structured errorCatalog API and --catalog CLI.
+
+Default behavior is retained except that the expanded error catalog now recognizes additional errors. New rotation and release-plan features are opt-in.
diff --git a/README.md b/README.md
index 9e16799..ae1a523 100644
--- a/README.md
+++ b/README.md
@@ -1,6 +1,24 @@
 # error-translator
 
-> **Version 0.3.0:** install from npm with Node 22.13+ or Node 24. See MIGRATION.md for changes from 0.2.0.
+## Browse the debugging library (0.4.0)
+
+46 built-in definitions cover filesystem, permissions, networking, module loading, streams, HTTP response lifecycle and JavaScript errors. Each has a specific explanation, likely causes and practical checks. Rubber-duck commentary has a distinct original line for every supported definition. No commands run automatically and unknown errors remain explicitly unrecognized.
+
+```sh
+npx @deployanyway/error-translator ERR_HTTP_HEADERS_SENT --mode rubber-duck
+npx @deployanyway/error-translator --catalog --json
+npx @deployanyway/error-translator --list
+```
+
+```js
+import { errorCatalog, translateError } from "@deployanyway/error-translator";
+console.log(errorCatalog({ mode: "plain" }));
+console.log(translateError({ code: "EACCES", message: "open config.json" }));
+```
+
+`errorCatalog(options?)` returns independent structured translations for the complete catalog. `--catalog` prints all guidance, or JSON with `--json`. Explicit codes still take precedence over message matching. This is a focused Node/JavaScript debugging catalog, not diagnosis of every platform or framework error. Technical reference: https://nodejs.org/api/errors.html.
+
+> **Version 0.4.0:** install from npm with Node 22.13+ or Node 24. See MIGRATION.md for changes from 0.2.0.
 
 [![npm version](https://img.shields.io/npm/v/%40deployanyway%2Ferror-translator)](https://www.npmjs.com/package/@deployanyway/error-translator)
 [![CI](https://github.com/DeployAnyway/error-translator/actions/workflows/ci.yml/badge.svg?branch=main)](https://github.com/DeployAnyway/error-translator/actions/workflows/ci.yml)
@@ -84,14 +102,54 @@ Invalid result shapes throw TypeError.
 
 ### Built-in errors
 
-| Code/name            | Guidance                                   |
-| -------------------- | ------------------------------------------ |
-| ECONNREFUSED         | Service availability, host, port, firewall |
-| ENOENT               | Missing paths and working directories      |
-| EADDRINUSE           | Port conflicts and duplicate instances     |
-| MODULE_NOT_FOUND     | CommonJS dependencies and paths            |
-| ERR_MODULE_NOT_FOUND | ES module dependencies, paths, extensions  |
-| TypeError            | Unexpected types and null/undefined values |
+| Code/name                      | Guidance                          |
+| ------------------------------ | --------------------------------- |
+| EACCES                         | Permission denied                 |
+| EPERM                          | Operation not permitted           |
+| EEXIST                         | Target already exists             |
+| ENOTDIR                        | Expected a directory              |
+| EISDIR                         | Expected a file                   |
+| ENOTEMPTY                      | Directory is not empty            |
+| EMFILE                         | Too many open files               |
+| ENFILE                         | System file table exhausted       |
+| ENOSPC                         | No space left                     |
+| EROFS                          | Read-only filesystem              |
+| EBUSY                          | Resource busy                     |
+| EXDEV                          | Cross-device operation            |
+| EPIPE                          | Broken pipe                       |
+| ECONNRESET                     | Connection reset                  |
+| ETIMEDOUT                      | Operation timed out               |
+| ENOTFOUND                      | Name lookup failed                |
+| EAI_AGAIN                      | Temporary name lookup failure     |
+| EADDRNOTAVAIL                  | Local address unavailable         |
+| ECONNABORTED                   | Connection aborted                |
+| ENETUNREACH                    | Network unreachable               |
+| EHOSTUNREACH                   | Host unreachable                  |
+| EINVAL                         | Invalid argument                  |
+| ABORT_ERR                      | Operation aborted                 |
+| ERR_INVALID_ARG_TYPE           | Wrong argument type               |
+| ERR_INVALID_ARG_VALUE          | Invalid argument value            |
+| ERR_OUT_OF_RANGE               | Value outside allowed range       |
+| ERR_HTTP_HEADERS_SENT          | Headers already sent              |
+| ERR_HTTP_INVALID_STATUS_CODE   | Invalid HTTP status               |
+| ERR_INVALID_URL                | Invalid URL                       |
+| ERR_PACKAGE_PATH_NOT_EXPORTED  | Package path not exported         |
+| ERR_PACKAGE_IMPORT_NOT_DEFINED | Package import not defined        |
+| ERR_INVALID_PACKAGE_CONFIG     | Invalid package configuration     |
+| ERR_UNKNOWN_FILE_EXTENSION     | Unknown module file extension     |
+| ERR_IMPORT_ATTRIBUTE_MISSING   | Required import attribute missing |
+| ERR_STREAM_WRITE_AFTER_END     | Write after stream end            |
+| ERR_STREAM_DESTROYED           | Stream destroyed                  |
+| ERR_SOCKET_BAD_PORT            | Invalid socket port               |
+| SyntaxError                    | Invalid JavaScript syntax         |
+| ReferenceError                 | Name is not available             |
+| RangeError                     | Value exceeds a permitted range   |
+| ECONNREFUSED                   | Connection refused                |
+| ENOENT                         | File or directory not found       |
+| EADDRINUSE                     | Address already in use            |
+| MODULE_NOT_FOUND               | Module not found                  |
+| ERR_MODULE_NOT_FOUND           | ES module not found               |
+| TypeError                      | Unexpected value type             |
 
 Translations describe likely causes, not a diagnosis. Keep the original error
 and stack trace for context. No AI API or remote service is used.
diff --git a/RELEASE-NOTES.md b/RELEASE-NOTES.md
index ba21b4e..3810819 100644
--- a/RELEASE-NOTES.md
+++ b/RELEASE-NOTES.md
@@ -1,3 +1,9 @@
-# 0.3.0 — 2026-10-08
+# 0.4.0 — 2026-10-08
 
-Adds useful API/CLI capabilities, TypeScript and CommonJS, coverage and installed-archive gates, and consistent contributor documentation. See README and MIGRATION.md for behavior and compatibility. Published through the repository’s trusted GitHub Actions workflow.
+46 distinct error definitions with explanations, causes and practical checks; original duck commentary for each; structured errorCatalog API and --catalog CLI.
+
+Requires Node 22.13+ or 24. See README for copyable CLI and API examples. All required source, type, coverage and installed archive checks passed locally; CI must pass on the final PR head before merging. Original content, MIT code, no backend calls from the libraries.
+
+## Compatibility
+
+Existing APIs remain available; new modes are explicit. Expanded error matching may recognize codes that were previously unknown.
diff --git a/index.d.cts b/index.d.cts
index a210e34..8f44227 100644
--- a/index.d.cts
+++ b/index.d.cts
@@ -21,3 +21,5 @@ export function translateErrors(
 ): Translation[];
 export function renderTranslation(result: Translation): string;
 export function listErrors(): string[];
+
+export function errorCatalog(options?: TranslationOptions): Translation[];
diff --git a/index.d.ts b/index.d.ts
index a210e34..8f44227 100644
--- a/index.d.ts
+++ b/index.d.ts
@@ -21,3 +21,5 @@ export function translateErrors(
 ): Translation[];
 export function renderTranslation(result: Translation): string;
 export function listErrors(): string[];
+
+export function errorCatalog(options?: TranslationOptions): Translation[];
diff --git a/package-lock.json b/package-lock.json
index ad6d16e..661b1be 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,12 +1,12 @@
 {
   "name": "@deployanyway/error-translator",
-  "version": "0.3.0",
+  "version": "0.4.0",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "@deployanyway/error-translator",
-      "version": "0.3.0",
+      "version": "0.4.0",
       "license": "MIT",
       "bin": {
         "error-translator": "bin/cli.js"
diff --git a/package.json b/package.json
index 3dd0a2f..97a575d 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@deployanyway/error-translator",
-  "version": "0.3.0",
+  "version": "0.4.0",
   "description": "Plain-English Node.js error explanations and debugging tips, because the stack trace has chosen violence.",
   "type": "module",
   "exports": {
diff --git a/src/cli.js b/src/cli.js
index 4053bbb..b680f7b 100644
--- a/src/cli.js
+++ b/src/cli.js
@@ -6,6 +6,7 @@ import {
   renderTranslation,
   translateErrors,
   listErrors,
+  errorCatalog,
 } from "./index.js";
 
 import { readStdin } from "./input.js";
@@ -19,12 +20,13 @@ try {
       json: { type: "boolean" },
       batch: { type: "boolean" },
       list: { type: "boolean" },
+      catalog: { type: "boolean" },
       mode: { type: "string", default: "plain" },
     },
   });
   if (values.help) {
     console.log(
-      'Usage: error-translator <error code or quoted message> [--json] [--mode plain|rubber-duck]\n\nTranslate errors into human-readable guidance. Without arguments, read stdin (256 KiB). --batch reads a JSON array of 1–100 errors. --list lists supported codes.\n\nOptions:\n  -h, --help     Show help\n  -v, --version  Show version\n  --json         Print a structured JSON result\n  --mode plain|rubber-duck   Keep useful guidance; add duck commentary\n\nExamples:\n  error-translator ECONNREFUSED\n  error-translator "TypeError: value is not a function" --json\n\nExit codes: 0 translation/help/version; 2 invalid arguments.',
+      'Usage: error-translator <error code or quoted message> [--json] [--mode plain|rubber-duck]\n\nTranslate errors into human-readable guidance. Without arguments, read stdin (256 KiB). --batch reads a JSON array of 1–100 errors. --list lists supported codes. --catalog prints all explanations and checks.\n\nOptions:\n  -h, --help     Show help\n  -v, --version  Show version\n  --json         Print a structured JSON result\n  --mode plain|rubber-duck   Keep useful guidance; add duck commentary\n\nExamples:\n  error-translator ECONNREFUSED\n  error-translator "TypeError: value is not a function" --json\n\nExit codes: 0 translation/help/version; 2 invalid arguments.',
     );
   } else if (values.version) {
     console.log(
@@ -32,6 +34,19 @@ try {
         readFileSync(new URL("../package.json", import.meta.url), "utf8"),
       ).version,
     );
+  } else if (values.catalog) {
+    if (positionals.length || values.batch || values.list)
+      throw new TypeError(
+        "--catalog does not accept input, --batch or --list.",
+      );
+    const catalog = errorCatalog({ mode: values.mode });
+    console.log(
+      values.json
+        ? JSON.stringify(catalog, null, 2)
+        : catalog
+            .map((item) => item.code + " — " + renderTranslation(item))
+            .join("\n\n---\n\n"),
+    );
   } else if (values.list) {
     if (positionals.length || values.batch)
       throw new TypeError("--list does not accept input or --batch.");
diff --git a/src/definitions.js b/src/definitions.js
index 7474583..ebad2b3 100644
--- a/src/definitions.js
+++ b/src/definitions.js
@@ -1,5 +1,7 @@
+import { extraDefinitions } from "./extra-definitions.js";
 // Keep technical guidance here so contributors can add errors without changing logic.
 export const definitions = {
+  ...extraDefinitions,
   ECONNREFUSED: {
     title: "Connection refused",
     explanation:
diff --git a/src/extra-definitions.js b/src/extra-definitions.js
new file mode 100644
index 0000000..92decce
--- /dev/null
+++ b/src/extra-definitions.js
@@ -0,0 +1,494 @@
+// Original explanations and practical checks; no automatic remediation.
+export const extraDefinitions = {
+  EACCES: {
+    title: "Permission denied",
+    explanation: "The process lacks permission for the requested operation.",
+    likelyCauses: [
+      "A directory or file belongs to another account",
+      "The application runs under a restricted service identity",
+    ],
+    suggestions: [
+      "Check the service identity and permissions on each parent directory.",
+      "Grant only the access the application needs; avoid running everything as administrator.",
+    ],
+  },
+  EPERM: {
+    title: "Operation not permitted",
+    explanation:
+      "The operating system rejected an operation even though the target may exist.",
+    likelyCauses: [
+      "A protected resource or locked file",
+      "An operation forbidden by the current platform or identity",
+    ],
+    suggestions: [
+      "Inspect the operation, ownership and platform restrictions.",
+      "Close the process holding the resource and retry only if the operation is intended.",
+    ],
+  },
+  EEXIST: {
+    title: "Target already exists",
+    explanation:
+      "A creation operation requires a new target, but that target already exists.",
+    likelyCauses: ["A repeated initialization step", "A filename collision"],
+    suggestions: [
+      "Check the target before creating it and make initialization idempotent.",
+      "Use a distinct name rather than deleting an existing target blindly.",
+    ],
+  },
+  ENOTDIR: {
+    title: "Expected a directory",
+    explanation:
+      "A path component used as a directory is actually another kind of file.",
+    likelyCauses: [
+      "A file appears in the middle of the path",
+      "A configuration value points to the wrong target",
+    ],
+    suggestions: [
+      "Inspect each path component and its type.",
+      "Correct the directory configuration before retrying.",
+    ],
+  },
+  EISDIR: {
+    title: "Expected a file",
+    explanation: "The operation received a directory where it expected a file.",
+    likelyCauses: [
+      "The filename is missing from a configured path",
+      "A directory was passed to a file operation",
+    ],
+    suggestions: [
+      "Check the complete path and inspect the target type.",
+      "Use the appropriate directory API when working with directories.",
+    ],
+  },
+  ENOTEMPTY: {
+    title: "Directory is not empty",
+    explanation:
+      "A directory operation requires an empty target, but entries remain.",
+    likelyCauses: [
+      "Generated files remain in the directory",
+      "Another process is still writing files",
+    ],
+    suggestions: [
+      "List the remaining entries and identify their owner.",
+      "Remove only confirmed disposable content or choose a new directory.",
+    ],
+  },
+  EMFILE: {
+    title: "Too many open files",
+    explanation: "The process has exhausted its available file descriptors.",
+    likelyCauses: [
+      "Handles are not closed",
+      "Too many files or sockets are opened concurrently",
+    ],
+    suggestions: [
+      "Close handles in cleanup paths and bound concurrent work.",
+      "Inspect descriptor usage before considering a higher process limit.",
+    ],
+  },
+  ENFILE: {
+    title: "System file table exhausted",
+    explanation: "The system cannot allocate another file handle.",
+    likelyCauses: [
+      "Many processes hold open files",
+      "The host has reached a system resource limit",
+    ],
+    suggestions: [
+      "Inspect host-wide handle usage and identify runaway processes.",
+      "Reduce concurrency and resolve leaks before changing system limits.",
+    ],
+  },
+  ENOSPC: {
+    title: "No space left",
+    explanation:
+      "The filesystem cannot allocate the space or resources required by the operation.",
+    likelyCauses: [
+      "The volume is full",
+      "Filesystem quotas or resource limits are exhausted",
+    ],
+    suggestions: [
+      "Check free space, quotas and the volume receiving the write.",
+      "Clear verified disposable data and investigate rapid growth.",
+    ],
+  },
+  EROFS: {
+    title: "Read-only filesystem",
+    explanation: "The target filesystem does not permit writes.",
+    likelyCauses: [
+      "A read-only container mount",
+      "A protected or recovery-mounted volume",
+    ],
+    suggestions: [
+      "Inspect mount settings and choose an intended writable data location.",
+      "Change mount configuration only when the write is part of the deployment design.",
+    ],
+  },
+  EBUSY: {
+    title: "Resource busy",
+    explanation:
+      "A resource cannot complete the requested operation while another operation holds it.",
+    likelyCauses: [
+      "A mounted or open resource",
+      "A concurrent operation has not finished",
+    ],
+    suggestions: [
+      "Identify the process or operation holding the resource.",
+      "Wait for its completion or coordinate ownership instead of looping without a limit.",
+    ],
+  },
+  EXDEV: {
+    title: "Cross-device operation",
+    explanation:
+      "An operation such as a rename crosses filesystem boundaries that it cannot cross directly.",
+    likelyCauses: [
+      "Temporary and destination files live on different volumes",
+      "A container mount creates a filesystem boundary",
+    ],
+    suggestions: [
+      "Create temporary files on the destination filesystem when atomic rename is required.",
+      "Use an intentional copy-and-cleanup workflow when atomic movement is unnecessary.",
+    ],
+  },
+  EPIPE: {
+    title: "Broken pipe",
+    explanation:
+      "The application wrote to a stream whose receiving end has closed.",
+    likelyCauses: [
+      "A downstream command exited",
+      "A peer disconnected before the write completed",
+    ],
+    suggestions: [
+      "Handle stream errors and stop producing data when the consumer closes.",
+      "Distinguish an expected pipeline close from an unexpected connection failure.",
+    ],
+  },
+  ECONNRESET: {
+    title: "Connection reset",
+    explanation:
+      "A connection was forcibly closed while the application was using it.",
+    likelyCauses: [
+      "The remote peer closed the connection",
+      "An intermediary interrupted the session",
+    ],
+    suggestions: [
+      "Inspect peer logs, timeout settings and recent connection changes.",
+      "Retry only safe operations with a bounded backoff and avoid duplicate side effects.",
+    ],
+  },
+  ETIMEDOUT: {
+    title: "Operation timed out",
+    explanation:
+      "A connection or operation did not finish within its allowed time.",
+    likelyCauses: [
+      "An unreachable or slow peer",
+      "A timeout shorter than the expected operation",
+    ],
+    suggestions: [
+      "Check network reachability, service latency and the configured timeout.",
+      "Use bounded retries only for operations that are safe to repeat.",
+    ],
+  },
+  ENOTFOUND: {
+    title: "Name lookup failed",
+    explanation:
+      "The requested hostname could not be resolved by the lookup operation.",
+    likelyCauses: [
+      "A misspelled hostname",
+      "Resolver configuration or lookup resources failed",
+    ],
+    suggestions: [
+      "Check the exact hostname and DNS behavior from the same runtime environment.",
+      "Do not assume every lookup failure proves the hostname does not exist.",
+    ],
+  },
+  EAI_AGAIN: {
+    title: "Temporary name lookup failure",
+    explanation: "Name resolution reported a temporary failure.",
+    likelyCauses: [
+      "A resolver is temporarily unavailable",
+      "A transient network or DNS problem",
+    ],
+    suggestions: [
+      "Check the resolver and network from the affected host.",
+      "Apply bounded retry with backoff and report persistent failures.",
+    ],
+  },
+  EADDRNOTAVAIL: {
+    title: "Local address unavailable",
+    explanation:
+      "The application tried to use an address that is not available on the local system.",
+    likelyCauses: [
+      "Binding to an address on another host",
+      "An interface address changed",
+    ],
+    suggestions: [
+      "Inspect local interfaces and the configured bind address.",
+      "Use the intended local interface rather than a remote destination address.",
+    ],
+  },
+  ECONNABORTED: {
+    title: "Connection aborted",
+    explanation: "A connection was aborted before the operation completed.",
+    likelyCauses: [
+      "A connection failure during setup or transfer",
+      "A local or intermediary cancellation",
+    ],
+    suggestions: [
+      "Inspect the failure timing and both ends of the connection.",
+      "Handle cancellation separately from application errors when appropriate.",
+    ],
+  },
+  ENETUNREACH: {
+    title: "Network unreachable",
+    explanation: "The host has no usable route to the requested network.",
+    likelyCauses: [
+      "Missing route or disconnected interface",
+      "Network isolation in a container or host",
+    ],
+    suggestions: [
+      "Inspect connectivity and routing in the application environment.",
+      "Confirm the destination network is intended to be reachable.",
+    ],
+  },
+  EHOSTUNREACH: {
+    title: "Host unreachable",
+    explanation:
+      "The destination host could not be reached through the available network path.",
+    likelyCauses: [
+      "The destination is unavailable",
+      "Routing or filtering blocks the path",
+    ],
+    suggestions: [
+      "Check the destination address and routing from the affected host.",
+      "Inspect network policy rather than disabling protection blindly.",
+    ],
+  },
+  EINVAL: {
+    title: "Invalid argument",
+    explanation: "The operating system rejected an argument to the operation.",
+    likelyCauses: [
+      "A value outside the operation contract",
+      "A platform-specific unsupported value",
+    ],
+    suggestions: [
+      "Inspect the syscall and the exact values passed to it.",
+      "Validate values against the API and platform requirements.",
+    ],
+  },
+  ABORT_ERR: {
+    title: "Operation aborted",
+    explanation: "An operation was cancelled through an abort mechanism.",
+    likelyCauses: [
+      "An AbortSignal was triggered",
+      "A caller timeout cancelled the operation",
+    ],
+    suggestions: [
+      "Inspect who owns the abort controller and when cancellation occurred.",
+      "Treat expected cancellation separately and clean up resources.",
+    ],
+  },
+  ERR_INVALID_ARG_TYPE: {
+    title: "Wrong argument type",
+    explanation: "A Node API received an argument of the wrong type.",
+    likelyCauses: [
+      "A missing or incorrect value",
+      "An unexpected return type passed to another API",
+    ],
+    suggestions: [
+      "Read the parameter name in the error and inspect its actual value.",
+      "Validate the argument at the boundary where it enters your application.",
+    ],
+  },
+  ERR_INVALID_ARG_VALUE: {
+    title: "Invalid argument value",
+    explanation: "An argument has a value the API does not accept.",
+    likelyCauses: [
+      "A valid type with an unsupported value",
+      "An invalid option combination",
+    ],
+    suggestions: [
+      "Inspect the named parameter and documented accepted values.",
+      "Validate options before calling the API.",
+    ],
+  },
+  ERR_OUT_OF_RANGE: {
+    title: "Value outside allowed range",
+    explanation: "A numeric or size argument falls outside the API range.",
+    likelyCauses: [
+      "An invalid offset or length",
+      "A computed limit exceeds the supported bounds",
+    ],
+    suggestions: [
+      "Check the reported minimum and maximum and the calculation producing the value.",
+      "Add boundary tests for zero, limits and oversized input.",
+    ],
+  },
+  ERR_HTTP_HEADERS_SENT: {
+    title: "Headers already sent",
+    explanation:
+      "The server tried to change headers after the response headers had been sent.",
+    likelyCauses: [
+      "Two code paths respond to the same request",
+      "An asynchronous callback runs after the response is complete",
+    ],
+    suggestions: [
+      "Trace every response path and return after sending the response.",
+      "Coordinate asynchronous work so only one path owns the final response.",
+    ],
+  },
+  ERR_HTTP_INVALID_STATUS_CODE: {
+    title: "Invalid HTTP status",
+    explanation: "The response status code is outside the accepted API range.",
+    likelyCauses: [
+      "An undefined value becomes a status",
+      "A business code is mistaken for an HTTP status",
+    ],
+    suggestions: [
+      "Check the status value before assigning or sending it.",
+      "Keep internal result codes separate from HTTP status codes.",
+    ],
+  },
+  ERR_INVALID_URL: {
+    title: "Invalid URL",
+    explanation: "The URL parser cannot interpret the supplied URL.",
+    likelyCauses: [
+      "A malformed absolute URL",
+      "A relative URL without a valid base",
+    ],
+    suggestions: [
+      "Inspect the original input and supply an explicit base for relative paths.",
+      "Validate user-controlled URL inputs before making requests.",
+    ],
+  },
+  ERR_PACKAGE_PATH_NOT_EXPORTED: {
+    title: "Package path not exported",
+    explanation: "A package exports map does not expose the requested subpath.",
+    likelyCauses: [
+      "Importing an internal package file",
+      "A dependency changed its public entry points",
+    ],
+    suggestions: [
+      "Inspect the package exports and use a documented public entry.",
+      "Upgrade or pin compatible dependencies instead of relying on private paths.",
+    ],
+  },
+  ERR_PACKAGE_IMPORT_NOT_DEFINED: {
+    title: "Package import not defined",
+    explanation: "A package imports map has no matching internal specifier.",
+    likelyCauses: [
+      "A missing imports mapping",
+      "A specifier is used outside its intended package scope",
+    ],
+    suggestions: [
+      "Check package.json imports and the exact specifier.",
+      "Keep internal import aliases inside the package that defines them.",
+    ],
+  },
+  ERR_INVALID_PACKAGE_CONFIG: {
+    title: "Invalid package configuration",
+    explanation: "Node could not use the package configuration.",
+    likelyCauses: ["Malformed package.json", "An invalid configuration field"],
+    suggestions: [
+      "Read the named package.json and validate its JSON and relevant fields.",
+      "Check the first configuration error before reinstalling dependencies.",
+    ],
+  },
+  ERR_UNKNOWN_FILE_EXTENSION: {
+    title: "Unknown module file extension",
+    explanation:
+      "The module loader does not recognize the file extension in this context.",
+    likelyCauses: [
+      "An unsupported file type is imported",
+      "The required build or loader is missing",
+    ],
+    suggestions: [
+      "Check the imported extension and the runtime module configuration.",
+      "Compile to a supported format or use a documented loader setup.",
+    ],
+  },
+  ERR_IMPORT_ATTRIBUTE_MISSING: {
+    title: "Required import attribute missing",
+    explanation: "A module import requires an attribute that was not provided.",
+    likelyCauses: [
+      "A JSON import lacks the required type attribute",
+      "An import was copied from a different runtime version",
+    ],
+    suggestions: [
+      "Check the module type and import syntax for your supported Node version.",
+      "Use the required import attributes or an appropriate file-reading API.",
+    ],
+  },
+  ERR_STREAM_WRITE_AFTER_END: {
+    title: "Write after stream end",
+    explanation: "Data was written after the writable stream had ended.",
+    likelyCauses: [
+      "A late callback writes to a closed stream",
+      "Multiple owners end and write the same stream",
+    ],
+    suggestions: [
+      "Trace the stream lifecycle and coordinate the writer with completion.",
+      "Test delayed callbacks and ensure end is called once work is complete.",
+    ],
+  },
+  ERR_STREAM_DESTROYED: {
+    title: "Stream destroyed",
+    explanation: "An operation used a stream after it had been destroyed.",
+    likelyCauses: [
+      "A prior error destroyed the stream",
+      "Cleanup ran while work was still pending",
+    ],
+    suggestions: [
+      "Inspect the original stream error and cancellation timing.",
+      "Stop dependent work when the stream closes or is destroyed.",
+    ],
+  },
+  ERR_SOCKET_BAD_PORT: {
+    title: "Invalid socket port",
+    explanation: "A socket port value is not accepted by the API.",
+    likelyCauses: [
+      "A malformed environment variable",
+      "A number outside the port range",
+    ],
+    suggestions: [
+      "Validate and parse the port configuration before creating the connection.",
+      "Do not substitute a silent default for a visibly invalid production setting.",
+    ],
+  },
+  SyntaxError: {
+    title: "Invalid JavaScript syntax",
+    explanation: "The parser cannot interpret the source or input syntax.",
+    likelyCauses: [
+      "Malformed JavaScript or JSON",
+      "Syntax unsupported by the current runtime",
+    ],
+    suggestions: [
+      "Read the first reported location and inspect nearby delimiters and tokens.",
+      "Confirm the input format and runtime version before changing unrelated code.",
+    ],
+  },
+  ReferenceError: {
+    title: "Name is not available",
+    explanation:
+      "An expression refers to a binding that is not available in its current scope or initialization state.",
+    likelyCauses: [
+      "A misspelled or out-of-scope variable",
+      "Access before initialization",
+    ],
+    suggestions: [
+      "Inspect the referenced name and its scope at the reported line.",
+      "Check initialization order and add a focused regression test.",
+    ],
+  },
+  RangeError: {
+    title: "Value exceeds a permitted range",
+    explanation:
+      "An operation received a value outside its allowed range or exhausted a range-related resource.",
+    likelyCauses: [
+      "An invalid numeric size or index",
+      "Excessive recursion or allocation",
+    ],
+    suggestions: [
+      "Read the exact message to distinguish numeric bounds from stack exhaustion.",
+      "Inspect boundary values and recursion termination rather than treating every RangeError alike.",
+    ],
+  },
+};
diff --git a/src/index.js b/src/index.js
index 3e94828..a20ed7e 100644
--- a/src/index.js
+++ b/src/index.js
@@ -8,6 +8,55 @@ export function translateErrors(errors, options = {}) {
   return Array.from(errors, (error) => translateError(error, options));
 }
 const duckLines = {
+  EACCES: "The file has a guest list. Your process is not on it.",
+  EPERM: "The operating system has declined your ambitious proposal.",
+  EEXIST: "The target is already here and has not agreed to be replaced.",
+  ENOTDIR: "That hallway is actually a cupboard.",
+  EISDIR: "You asked for one file and received the whole neighborhood.",
+  ENOTEMPTY: "The directory still has roommates.",
+  EMFILE: "Your process opened every door and forgot to close them.",
+  ENFILE: "The host has run out of chairs for file handles.",
+  ENOSPC: "The disk has eaten the final snack.",
+  EROFS: "This filesystem is a museum: look, but do not rearrange.",
+  EBUSY: "The resource is in another meeting.",
+  EXDEV: "The rename has reached the border and needs a different passport.",
+  EPIPE: "The audience left before your stream finished the speech.",
+  ECONNRESET: "The other end hung up without the usual pleasantries.",
+  ETIMEDOUT: "The operation is late and has not brought a believable excuse.",
+  ENOTFOUND: "The hostname is not answering roll call.",
+  EAI_AGAIN: "DNS requests a brief intermission, not eternal optimism.",
+  EADDRNOTAVAIL: "That address does not live on this machine.",
+  ECONNABORTED: "The connection left before the conversation was finished.",
+  ENETUNREACH: "The packet has no road to the destination.",
+  EHOSTUNREACH:
+    "The route exists; the destination is still playing hard to reach.",
+  EINVAL: "The argument has failed the entrance interview.",
+  ABORT_ERR: "The caller pulled the emergency stop. Ask why before restarting.",
+  ERR_INVALID_ARG_TYPE:
+    "The parameter ordered a string and received a surprise guest.",
+  ERR_INVALID_ARG_VALUE: "The type is correct. Its life choices are not.",
+  ERR_OUT_OF_RANGE: "The number wandered beyond the approved fence.",
+  ERR_HTTP_HEADERS_SENT:
+    "The response left the station. You cannot redecorate its headers now.",
+  ERR_HTTP_INVALID_STATUS_CODE:
+    "That number is not a useful mood for an HTTP response.",
+  ERR_INVALID_URL:
+    "The address has syntax ambitions but no navigable destination.",
+  ERR_PACKAGE_PATH_NOT_EXPORTED: "You are trying the package staff entrance.",
+  ERR_PACKAGE_IMPORT_NOT_DEFINED:
+    "The alias has not been introduced to this package.",
+  ERR_INVALID_PACKAGE_CONFIG:
+    "The package instructions have become abstract art.",
+  ERR_UNKNOWN_FILE_EXTENSION: "The loader does not speak this file dialect.",
+  ERR_IMPORT_ATTRIBUTE_MISSING:
+    "The import arrived without its required name badge.",
+  ERR_STREAM_WRITE_AFTER_END:
+    "The stream said goodbye. Your callback is still talking.",
+  ERR_STREAM_DESTROYED: "The stream has retired. Please respect its notice.",
+  ERR_SOCKET_BAD_PORT: "The port number did not pass the harbor inspection.",
+  SyntaxError: "The parser has found punctuation with questionable intentions.",
+  ReferenceError: "That name is not available for comment in this scope.",
+  RangeError: "The value or call stack has climbed over the fence.",
   ECONNREFUSED: "Your app knocked. The service has apparently gone for coffee.",
   ENOENT: "The file is playing hide-and-seek. It is currently winning.",
   EADDRINUSE: "Two servers reserved the same chair. Only one gets to sit.",
@@ -114,3 +163,8 @@ export function renderTranslation(result) {
       : []),
   ].join("\n\n");
 }
+
+/** Read the built-in guidance as independent structured records. */
+export function errorCatalog(options = {}) {
+  return listErrors().map((code) => translateError({ code }, options));
+}
diff --git a/test/catalog.test.js b/test/catalog.test.js
new file mode 100644
index 0000000..7227ff5
--- /dev/null
+++ b/test/catalog.test.js
@@ -0,0 +1,48 @@
+import { URL } from "node:url";
+import test from "node:test";
+import assert from "node:assert/strict";
+import { listErrors, translateError } from "../src/index.js";
+test("expanded technical catalog covers practical errors without pretending to recognize unknown codes", () => {
+  assert.equal(listErrors().length, 46);
+  for (const code of listErrors()) {
+    const result = translateError({ code });
+    assert.equal(result.code, code);
+    assert.ok(result.likelyCauses.length >= 2);
+    assert.ok(result.suggestions.length >= 2);
+    result.suggestions.pop();
+    assert.ok(translateError(code).suggestions.length >= 2);
+  }
+  assert.match(
+    translateError("ERR_HTTP_HEADERS_SENT").suggestions.join(" "),
+    /response/,
+  );
+  assert.match(translateError("ENOSPC").suggestions.join(" "), /space/);
+  assert.match(translateError("EACCES").suggestions.join(" "), /permissions/);
+  assert.equal(
+    translateError({ code: "CUSTOM", message: "ENOENT" }).title,
+    "Unrecognized error",
+  );
+  assert.equal(
+    translateError("ERR_STREAM_WRITE_AFTER_END: write after end").code,
+    "ERR_STREAM_WRITE_AFTER_END",
+  );
+});
+import { errorCatalog } from "../src/index.js";
+import { spawnSync } from "node:child_process";
+test("structured catalogs are independent and CLI JSON agrees with API", () => {
+  const catalog = errorCatalog({ mode: "rubber-duck" });
+  assert.equal(catalog.length, 46);
+  catalog[0].suggestions.pop();
+  assert.equal(errorCatalog()[0].suggestions.length, 2);
+  assert.throws(() => errorCatalog({ mode: "unknown" }), RangeError);
+  const run = (args) =>
+    spawnSync(process.execPath, ["bin/cli.js", ...args], {
+      cwd: new URL("..", import.meta.url),
+      encoding: "utf8",
+    });
+  let result = run(["--catalog", "--json"]);
+  assert.equal(result.status, 0);
+  assert.deepEqual(JSON.parse(result.stdout), errorCatalog());
+  assert.match(run(["--catalog"]).stdout, /EACCES/);
+  assert.equal(run(["--catalog", "ENOENT"]).status, 2);
+});
diff --git a/test/index.test.js b/test/index.test.js
index 50ad081..a043c19 100644
--- a/test/index.test.js
+++ b/test/index.test.js
@@ -92,7 +92,7 @@ test("CLI text, JSON, help, version, unknown errors", () => {
   );
   assert.equal(cli("--help").status, 0);
   assert.ok(cli("--help").stdout.includes("Usage:"));
-  assert.equal(cli("--version").stdout.trim(), "0.3.0");
+  assert.equal(cli("--version").stdout.trim(), "0.4.0");
   assert.equal(cli("custom error").status, 0);
 });
 test("CLI invalid arguments exit 2 with stderr", () => {
diff --git a/test/types.cts b/test/types.cts
index 4a8c22d..d09a40b 100644
--- a/test/types.cts
+++ b/test/types.cts
@@ -4,3 +4,4 @@ api.translateErrors(["ENOENT", new Error("TypeError")], {
 });
 // @ts-expect-error invalid literal
 api.translateError("x", { mode: "pirate" });
+api.errorCatalog({ mode: "plain" })[0].suggestions;
diff --git a/test/types.mts b/test/types.mts
index 1a21628..8bce457 100644
--- a/test/types.mts
+++ b/test/types.mts
@@ -4,3 +4,5 @@ api.translateErrors(["ENOENT", new Error("TypeError")], {
 });
 // @ts-expect-error invalid literal
 api.translateError("x", { mode: "pirate" });
+import { errorCatalog } from "@deployanyway/error-translator";
+errorCatalog({ mode: "rubber-duck" })[0].suggestions;