> ## Documentation Index
> Fetch the complete documentation index at: https://www.testmuai.com/docs/llms.txt
> Use this file to discover all available pages before exploring further.
# Error Codes Reference
> Complete reference of Kane CLI result codes: what each code means, why it occurred, and what action to take. Designed for both human and AI agent consumption.
export const BrandName = ({type = 'default'}) => {
const getBrandName = () => 'TestMu AI';
const getBrandNameLowercase = () => 'testmu ai';
if (type === 'lowercase') {
return getBrandNameLowercase();
}
return getBrandName();
};
***
**Using Claude Code, Cursor, or another coding agent?** Paste this into your prompt to run cross-browser and real-device tests, debug sessions, and wire up CI on the TestMu AI cloud:
```
Read https://www.testmuai.com/support/docs/SKILL.md to set up TestMu AI (formerly LambdaTest) cloud testing.
```
Every Kane CLI run ends with a `result_code` in the `run_end` event. This page lists every code, explains what triggered it, and tells you what to do next.
## How to Read Result Codes
Result codes follow HTTP-style groupings:
| Range | Category | Meaning |
| ------- | --------------- | ---------------------------------------------------------------- |
| **1xx** | Success | The objective completed successfully. |
| **2xx** | Cancelled | The run was cancelled before completion. |
| **3xx** | Stuck | The agent could not make further progress. |
| **4xx** | Agent Error | An internal agent failure prevented completion. |
| **5xx** | Infra Error | A platform or infrastructure issue stopped the run. |
| **6xx** | Blocker | An external obstacle (CAPTCHA, paywall, etc.) blocked the agent. |
| **7xx** | Assertion Error | The objective's assertions or checkpoints failed. |
The `run_end` event includes both `result_code` (numeric) and `reason_code` (descriptive string):
```json theme={null}
{
"type": "run_end",
"status": "failed",
"result_code": 310,
"reason_code": "stuck.max_steps",
"summary": "Agent reached maximum step limit..."
}
```
***
## 1xx — Success
### 100 COMPLETE
| Field | Value |
| ----------------- | ------------------------------------------------------------------------- |
| **Reason code** | `success.complete` |
| **Status** | `COMPLETE` |
| **What happened** | All checkpoints passed and the agent confirmed the objective is achieved. |
| **Action** | None required. |
***
## 2xx — Cancelled
### 200 USER\_CANCELLED
| Field | Value |
| ----------------- | ---------------------------------------------------------------------------------------- |
| **Reason code** | `cancelled.user` |
| **Status** | `CANCELLED` |
| **What happened** | The run was cancelled by the caller (e.g., Ctrl+C, `cancel` event, or API cancellation). |
| **Action** | No action required. Re-run the objective if needed. |
***
## 3xx — Stuck
The agent ran into a dead end. These are not crashes - the agent recognized it could not make further progress.
### 310 MAX\_STEPS
| Field | Value |
| ----------------- | ------------------------------------------------------------------------------------------------------ |
| **Reason code** | `stuck.max_steps` |
| **Status** | `STUCK` |
| **What happened** | The agent exceeded the configured `--max-steps` limit before completing the objective. |
| **Action** | Increase `--max-steps` (e.g., `--max-steps 60`), or break the objective into smaller, sequential runs. |
### 320 DAG\_CYCLE
| Field | Value |
| ----------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------ |
| **Reason code** | `stuck.dag_cycle` |
| **Status** | `STUCK` |
| **What happened** | The agent detected 3 repeated page-state cycles (it keeps returning to the same state after each action). |
| **Action** | Rephrase the objective with a different approach. The current path leads to a loop - try an alternative navigation route or add explicit intermediate steps. |
### 330 AP\_STUCK
| Field | Value |
| ----------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| **Reason code** | `stuck.ap_stuck` |
| **Status** | `STUCK` |
| **What happened** | The action planner determined there are no viable actions available on the current page to progress toward the objective. |
| **Action** | Manual intervention is needed. Check the screenshot at `{session_id}/runs/{run_dir}/run-test/screenshots/` to understand what page state the agent ended on. You may need to adjust the objective, provide credentials, or navigate to a different starting URL. |
***
## 4xx — Agent Error
An internal agent component failed. These typically indicate a transient issue or a problem with the session state.
### 410 AP\_NO\_ACTION
| Field | Value |
| ----------------- | ----------------------------------------------------------------------------------------------------------------------------------- |
| **Reason code** | `agent_error.ap_no_action` |
| **Status** | `ERROR` |
| **What happened** | The action planner returned 3 consecutive empty decisions (no action selected). |
| **Action** | Retry the run. If the error persists, simplify the objective or file a [bug report](https://github.com/LambdaTest/kane-cli/issues). |
### 420 REASONING\_FAILURE
| Field | Value |
| ----------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| **Reason code** | `agent_error.reasoning_failure` |
| **Status** | `ERROR` |
| **What happened** | An unhandled exception occurred in the reasoning engine. |
| **Action** | Check `{session_id}/runs/{run_dir}/run.log` for the full stack trace. Retry the run - this is usually transient. If it persists, file a [bug report](https://github.com/LambdaTest/kane-cli/issues) with the log file. |
### 430 CLEAN\_START\_INVALID
| Field | Value |
| ----------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| **Reason code** | `agent_error.clean_start_invalid` |
| **Status** | `ERROR` |
| **What happened** | The `clean_start` validation failed - the agent could not establish a valid initial session state (e.g., the starting URL did not load, or the browser context is corrupted). |
| **Action** | Verify the `--url` is accessible and loads correctly. If using `--cdp-endpoint`, ensure the browser is in a clean state. |
### 440 CHILD\_FAILED
| Field | Value |
| ----------------- | ---------------------------------------------------------------------------------------------------------------------------------------- |
| **Reason code** | `agent_error.child_failed` |
| **Status** | `ERROR` |
| **What happened** | A child agent (spawned for a sub-objective during analysis) failed. The parent run cannot continue. |
| **Action** | Check the `child_agent_end` event in the NDJSON output for the child's failure details. Fix the child objective, then re-run the parent. |
***
## 5xx — Infra Error
Platform or infrastructure failures. These are independent of the objective itself.
### 510 SCREENSHOT\_FAILED
| Field | Value |
| ----------------- | ---------------------------------------------------------------------------------------------------------------------------------- |
| **Reason code** | `infra_error.screenshot_failed` |
| **Status** | `ERROR` |
| **What happened** | The browser failed to capture a screenshot (Playwright exception). The agent cannot proceed without visual input. |
| **Action** | Check that the browser is still running. If using `--cdp-endpoint`, verify the connection is alive. Restart the browser and retry. |
### 520 BROWSER\_CRASHED
| Field | Value |
| ----------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------- |
| **Reason code** | `infra_error.browser_crashed` |
| **Status** | `ERROR` |
| **What happened** | The browser process crashed or became unresponsive. |
| **Action** | Restart the browser and retry the run. If this happens repeatedly, check available system memory and ensure no other processes are competing for resources. |
### 530 TIMEOUT
| Field | Value |
| ----------------- | ------------------------------------------------------------------------------------------------------------ |
| **Reason code** | `infra_error.timeout` |
| **Status** | `ERROR` |
| **What happened** | The run exceeded its configured timeout. |
| **Action** | Increase `--timeout` (in seconds): `--timeout 300`. If the objective is complex, break it into smaller runs. |
### 540 EVENT\_DISPATCH
| Field | Value |
| ----------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| **Reason code** | `infra_error.event_dispatch` |
| **Status** | `ERROR` |
| **What happened** | A custom event dispatch (e.g., browser event injection) failed. |
| **Action** | Check `{session_id}/runs/{run_dir}/run.log` for the failing event handler. This usually indicates a page script error or an incompatible browser state. Retry the run, and if it persists, file a [bug report](https://github.com/LambdaTest/kane-cli/issues). |
### 550 CONTROLLER\_AUTH
| Field | Value |
| ----------------- | ------------------------------------------------------------------------------------------------------------------------- |
| **Reason code** | `infra_error.controller_auth` |
| **Status** | `ERROR` |
| **What happened** | The controller returned a `401 Unauthorized` response. Your authentication token has expired or is invalid. |
| **Action** | Refresh your authentication token: |
```bash theme={null}
kane-cli login
# or re-run login with basic auth
kane-cli login --username "YOUR_LT_USERNAME" --access-key "YOUR_LT_ACCESS_KEY"
```
Verify with `kane-cli whoami`, then retry the run.
### 560 CREDITS\_EXHAUSTED
| Field | Value |
| ----------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| **Reason code** | `infra_error.credits_exhausted` |
| **Status** | `ERROR` |
| **What happened** | The controller returned a `402 Payment Required` response. Your account has no remaining credits for AI agent runs. |
| **Action** | Purchase additional credits or upgrade your plan on the [ billing page](https://billing.lambdatest.com/billing/plans/). Contact your account administrator if you are on a team plan. |
***
## 6xx — Blocker
An external obstacle on the target website prevented the agent from completing the objective. These are not agent bugs - they require changes to the environment or objective.
### 610 CAPTCHA
| Field | Value |
| ----------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| **Reason code** | `blocker.captcha` |
| **Status** | `ERROR` |
| **What happened** | The page presented a CAPTCHA challenge that the agent cannot solve. |
| **Action** | Solve the CAPTCHA manually in an interactive session first, then re-run. Alternatively, use a test environment that has CAPTCHAs disabled, or allowlist the test IP. |
### 620 PAYWALL
| Field | Value |
| ----------------- | ------------------------------------------------------------------------------------------------------------------------------------------------- |
| **Reason code** | `blocker.paywall` |
| **Status** | `ERROR` |
| **What happened** | The page requires a paid subscription to access the content the objective needs. |
| **Action** | Provide credentials for a subscribed account via [variables](/docs/docs/kane-cli-variables-and-context/), or test against a non-paywalled environment. |
### 640 BLOCKED
| Field | Value |
| ----------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| **Reason code** | `blocker.blocked` |
| **Status** | `ERROR` |
| **What happened** | The target site blocked access (IP ban, WAF rule, geo-restriction, or bot detection). |
| **Action** | Use a different IP address, allowlist the test IP on the target site, or use a different test account. Check whether the site has bot-detection that needs to be configured for testing. |
### 650 ERROR\_PAGE
| Field | Value |
| ----------------- | -------------------------------------------------------------------------------------------------------------------------------------------------- |
| **Reason code** | `blocker.error_page` |
| **Status** | `ERROR` |
| **What happened** | The page returned an HTTP error (404 Not Found, 500 Internal Server Error, etc.) instead of the expected content. |
| **Action** | Verify the `--url` is correct and the target site is operational. Check `{session_id}/runs/{run_dir}/run-test/screenshots/` to see the error page. |
### 660 AUTH\_NO\_CREDENTIALS
| Field | Value |
| ----------------- | -------------------------------------------------------------------------------------------------- |
| **Reason code** | `blocker.auth_no_credentials` |
| **Status** | `ERROR` |
| **What happened** | The agent encountered a login page but no credentials were provided in the objective or variables. |
| **Action** | Provide login credentials using [variables](/docs/docs/kane-cli-variables-and-context/): |
```bash theme={null}
kane-cli run "Log in and navigate to dashboard" \
--url https://myapp.com/login \
--variables '{"username": {"value": "test@example.com"}, "password": {"value": "s3cret", "secret": true}}' \
--agent
```
***
## 7xx — Assertion Error
The agent completed its actions but one or more assertions or checkpoints did not pass.
### 710 FINAL\_VERIFICATION
| Field | Value |
| ----------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |
| **Reason code** | `assertion_error.final_verification` |
| **Status** | `ASSERTION_ERROR` |
| **What happened** | The final checkpoint failed. The agent performed all actions but the end state did not match the expected outcome. |
| **Action** | This means the objective was **not achieved**. Review the screenshot at `{session_id}/runs/{run_dir}/run-test/screenshots/` to see the final page state. The objective itself may need adjustment, or the application under test may have a bug. |
### 720 CHECKPOINT\_FAILED
| Field | Value |
| ----------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| **Reason code** | `assertion_error.checkpoint_failed` |
| **Status** | `ASSERTION_ERROR` |
| **What happened** | An inline checkpoint (mid-run assertion) failed. The agent detected that an intermediate condition was not met. |
| **Action** | Check which checkpoint failed in the step logs at `{session_id}/runs/{run_dir}/run-test/step_N.json`. The assertion condition may be too strict, or the application did not reach the expected state at that point. |
### 730 NO\_BRANCH\_MATCHED
| Field | Value |
| ----------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| **Reason code** | `assertion_error.no_branch_matched` |
| **Status** | `ASSERTION_ERROR` |
| **What happened** | An if-else objective had multiple branches, but none of the conditions matched the actual page state. |
| **Action** | Review your branching conditions. Add a fallback branch, or check the screenshot to see what state the page was actually in. Adjust conditions to cover the observed state. |
***
## Quick Lookup Table
| Code | Name | Reason Code | Action |
| ---- | --------------------- | ------------------------------------ | ---------------------------------- |
| 100 | COMPLETE | `success.complete` | Done |
| 200 | USER\_CANCELLED | `cancelled.user` | Re-run if needed |
| 310 | MAX\_STEPS | `stuck.max_steps` | Increase `--max-steps` or simplify |
| 320 | DAG\_CYCLE | `stuck.dag_cycle` | Try a different approach |
| 330 | AP\_STUCK | `stuck.ap_stuck` | Manual intervention needed |
| 410 | AP\_NO\_ACTION | `agent_error.ap_no_action` | Retry the run |
| 420 | REASONING\_FAILURE | `agent_error.reasoning_failure` | Check logs, retry |
| 430 | CLEAN\_START\_INVALID | `agent_error.clean_start_invalid` | Fix session state |
| 440 | CHILD\_FAILED | `agent_error.child_failed` | Check child agent details |
| 510 | SCREENSHOT\_FAILED | `infra_error.screenshot_failed` | Check browser |
| 520 | BROWSER\_CRASHED | `infra_error.browser_crashed` | Restart browser |
| 530 | TIMEOUT | `infra_error.timeout` | Increase `--timeout` |
| 540 | EVENT\_DISPATCH | `infra_error.event_dispatch` | Check event handler |
| 550 | CONTROLLER\_AUTH | `infra_error.controller_auth` | Run `kane-cli login` |
| 560 | CREDITS\_EXHAUSTED | `infra_error.credits_exhausted` | Purchase credits |
| 610 | CAPTCHA | `blocker.captcha` | Solve manually or disable |
| 620 | PAYWALL | `blocker.paywall` | Provide subscription |
| 640 | BLOCKED | `blocker.blocked` | Change IP or account |
| 650 | ERROR\_PAGE | `blocker.error_page` | Fix the URL |
| 660 | AUTH\_NO\_CREDENTIALS | `blocker.auth_no_credentials` | Provide credentials |
| 710 | FINAL\_VERIFICATION | `assertion_error.final_verification` | Objective not achieved |
| 720 | CHECKPOINT\_FAILED | `assertion_error.checkpoint_failed` | Check assertion condition |
| 730 | NO\_BRANCH\_MATCHED | `assertion_error.no_branch_matched` | Update branch conditions |
***
## Handling Errors in Agent Mode
When consuming Kane CLI output programmatically, use `result_code` ranges to determine your next action:
```bash theme={null}
# Run and capture the result
RESULT=$(kane-cli run "..." --agent --headless 2>/dev/null | tail -1)
CODE=$(echo "$RESULT" | jq -r '.result_code')
case $CODE in
100) echo "Passed" ;;
2*) echo "Cancelled" ;;
3*) echo "Stuck: $(echo $RESULT | jq -r '.reason_code')" ;;
4*) echo "Agent error: retry recommended" ;;
5*) echo "Infra error: check environment" ;;
6*) echo "Blocked: manual intervention needed" ;;
7*) echo "Assertion failed: check test conditions" ;;
esac
```
***
## Related Resources
* [Agent Mode](/docs/docs/kane-cli-agent-mode/): NDJSON output format and event schema
* [Troubleshooting](/docs/docs/kane-cli-troubleshooting/): Common issues and fixes
* [CLI Reference](/docs/docs/kane-cli-cli-reference/): Full flag and command reference