> ## Documentation Index
> Fetch the complete documentation index at: https://docs.langchain.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Errors

This page contains guides around resolving common errors you may find while building with LangChain and LangGraph.

Errors referenced below will have an `lc_error_code` property corresponding to one of the below codes when they are thrown in code.

| Error code                                                                                              |
| ------------------------------------------------------------------------------------------------------- |
| [GRAPH\_RECURSION\_LIMIT](/oss/javascript/langgraph/errors/GRAPH_RECURSION_LIMIT)                       |
| [INVALID\_CHAT\_HISTORY](/oss/javascript/langgraph/errors/INVALID_CHAT_HISTORY)                         |
| [INVALID\_CONCURRENT\_GRAPH\_UPDATE](/oss/javascript/langgraph/errors/INVALID_CONCURRENT_GRAPH_UPDATE)  |
| [INVALID\_GRAPH\_NODE\_RETURN\_VALUE](/oss/javascript/langgraph/errors/INVALID_GRAPH_NODE_RETURN_VALUE) |
| [INVALID\_PROMPT\_INPUT](/oss/javascript/langchain/errors/INVALID_PROMPT_INPUT)                         |
| [INVALID\_TOOL\_RESULTS](/oss/javascript/langchain/errors/INVALID_TOOL_RESULTS)                         |
| [MESSAGE\_COERCION\_FAILURE](/oss/javascript/langchain/errors/MESSAGE_COERCION_FAILURE)                 |
| [MISSING\_CHECKPOINTER](/oss/javascript/langgraph/errors/MISSING_CHECKPOINTER)                          |
| [MODEL\_AUTHENTICATION](/oss/javascript/langchain/errors/MODEL_AUTHENTICATION)                          |
| [MODEL\_NOT\_FOUND](/oss/javascript/langchain/errors/MODEL_NOT_FOUND)                                   |
| [MODEL\_RATE\_LIMIT](/oss/javascript/langchain/errors/MODEL_RATE_LIMIT)                                 |
| [MULTIPLE\_SUBGRAPHS](/oss/javascript/langgraph/errors/MULTIPLE_SUBGRAPHS)                              |
| [OUTPUT\_PARSING\_FAILURE](/oss/javascript/langchain/errors/OUTPUT_PARSING_FAILURE)                     |

***

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