jeremylongshore Lindy Common Errors
Overview
Troubleshooting guide for Lindy AI agent errors. Lindy agents fail at specific points in the workflow: trigger reception, action execution, condition evaluation, or exit condition evaluation. This guide covers each failure class.
Prerequisites
- Access to Lindy dashboard (https://app.lindy.ai)
- Ability to view agent Tasks tab for error details
- For webhook debugging: curl installed
Trigger Errors
Webhook Not Firing
Symptoms: No task created when webhook is sent Causes & Solutions:
| Cause | Diagnostic | Fix |
|---|---|---|
| Wrong URL | Check webhook URL in agent config | Copy exact URL from trigger settings |
| Missing auth | curl -v shows 401 |
Add Authorization: Bearer <secret> header |
| Agent inactive | Dashboard shows agent paused | Activate the agent |
| Filter blocking | Trigger filter too restrictive | Review filter conditions, test with broader filter |
| Wrong HTTP method | Using GET instead of POST | Lindy webhooks require POST |
# Diagnostic: Test webhook connectivity
curl -v -X POST "https://public.lindy.ai/api/v1/webhooks/YOUR_ID" \
-H "Authorization: Bearer YOUR_SECRET" \
-H "Content-Type: application/json" \
-d '{"test": true}'
# Expect: 200 OK
Email Trigger Not Activating
Symptoms: Emails arrive but agent does not wake up Solutions:
- Verify Gmail/Outlook authorization is current (re-authorize if expired)
- Check label filter — Lindy Email Received trigger can filter by label
- Confirm email matches trigger filter conditions (sender, subject, etc.)
- Check that agent is active, not paused
Schedule Trigger Missed
Symptoms: Agent did not run at scheduled time Solutions:
- Verify timezone settings match your expectation
- Check credit balance — agents stop if credits exhausted
- Review schedule configuration (daily vs weekday vs custom)
Action Errors
Slack Send Failed
| Error | Cause | Fix |
|---|---|---|
| Channel not found | Channel name wrong or private | Use exact channel name; ensure bot is invited |
| Not authorized | Slack token expired | Re-authorize Slack in Lindy integrations |
| Rate limited | Too many messages | Reduce trigger frequency or batch messages |
Gmail Send Failed
| Error | Cause | Fix |
|---|---|---|
| Authentication expired | OAuth token expired | Re-authorize Gmail in Settings |
| Recipient rejected | Invalid email address | Validate email format in prior step |
| Draft not found | Thread ID mismatch | Verify thread context in action config |
HTTP Request Action Failed
| Error | Cause | Fix |
|---|---|---|
| Connection refused | Target API down | Verify target URL is reachable |
| 401 Unauthorized | Auth header misconfigured | Check Authorization header value |
| Timeout | Target API slow | Increase timeout or optimize target endpoint |
| SSL error | Invalid certificate | Ensure target uses valid HTTPS cert |
# Diagnostic: Test target API independently
curl -v -X POST "https://api.yourapp.com/endpoint" \
-H "Content-Type: application/json" \
-d '{"test": true}'
Run Code Action Failed
| Error | Cause | Fix |
|---|---|---|
| Import error | Library not available | Use only pre-installed libraries (pandas, numpy, etc.) |
| Type error | Input variable is string | Cast explicitly: int(var), json.loads(var) |
| Timeout | Long-running computation | Optimize code; avoid infinite loops |
| Return value empty | No return statement |
Add explicit return with result data |
Knowledge Base Returns No Results
| Cause | Fix |
|---|---|
| Fuzziness at 0 (keyword only) | Increase to 100 for semantic search |
| Content not indexed | Trigger Resync Knowledge Base action |
| Query too vague | Switch field to AI Prompt mode with specific instructions |
| File too large (>20MB) | Split into smaller files |
Agent Step Errors
Agent Loops Indefinitely
Cause: Exit conditions never satisfied Fix: Add measurable, achievable exit conditions:
Primary: "Found at least 3 relevant results"
Fallback: "Made 5 search attempts without finding results"
Agent Picks Wrong Condition Branch
Cause: Ambiguous condition prompt Fix: Make conditions mutually exclusive with clear criteria:
Branch A: "Go down this path if the email mentions billing, payment, or invoice"
Branch B: "Go down this path if the email mentions a technical issue, bug, or error"
Branch C: "Go down this path for all other topics"
Credit Overrun Warning
Symptom: "Task using more resources than expected" pause Cause: Agent step consuming too many credits (complex reasoning) Fix: Simplify prompt, reduce available skills (2-4 max), use smaller model
Debugging Checklist
- Open agent Tasks tab — find the failed task
- Click into the task — review each step's input/output
- Identify the failing step (red indicator)
- Check the step's error message and stack trace
- Verify integration authorizations are current
- Test the trigger independently (curl for webhooks)
- Test the action independently (manual run)
- Check credit balance — insufficient credits halt execution
Error Handling
| Error Category | HTTP Status | Retry? | Notes |
|---|---|---|---|
| Auth failure | 401 | No | Re-authorize integration |
| Rate limited | 429 | Yes | Wait for credit reset |
| Agent not found | 404 | No | Verify agent exists and is active |
| Action timeout | 504 | Yes | Simplify step or increase timeout |
| Run Code error | 500 | Maybe | Fix code, then retry |
| Credit exhausted | 402 | No | Upgrade plan or wait for monthly reset |
Resources
- Lindy Documentation
- Lindy Community
- Lindy Status
Next Steps
Proceed to lindy-debug-bundle for comprehensive diagnostics.
Source: jeremylongshore/claude-code-plugins-plus-skills → skills/.curated/lindy-common-errors/SKILL.md
Also appears in: jeremylongshore/claude-code-plugins-plus-skills/plugins/saas-packs/lindy-pack/skills/lindy-common-errors/SKILL.md