The error message you’re receiving, [400 Bad Request] The input token count (1377054) exceeds the maximum number of tokens allowed (1048576), is a clear indication that the data you are sending to the Gemini 2.5 Pro model is too large. The model has a hard limit on the number of tokens it can process in a single request, and your input is significantly over that limit.
This is a common issue when dealing with large files, long conversation histories, or extensive data in your prompts. You can’t increase the model’s token limit, so the solution is to reduce the size of your input.
Here are some strategies to solve this problem:
* Shrink your input: The most direct solution is to make your prompt and any associated data (like text from a file, a conversation history, or other content) shorter.
* Use the countTokens method: Many of the Gemini SDKs provide a countTokens function. You can use this to check the token count of your prompt before you send it to the model. This allows you to programmatically manage your input size and avoid the error.
* Summarize or pre-process your data: Instead of sending the full, raw text, you can summarize it or extract only the most relevant information before making the API call. This is particularly useful for things like long documents or chat histories.
* Implement Retrieval-Augmented Generation (RAG): For applications that need to interact with a large knowledge base, a more advanced solution is to use RAG. This involves storing your data in a separate database and then, for each user query, retrieving only the most relevant snippets to include in the prompt. This keeps your token count low while still allowing the model to access a large amount of information.
* Use a ChatSession with CachedContent (if applicable): If your app involves a conversation around a set of static documents, a feature like CachedContent can be a very effective solution. It processes and tokenizes the large files once, and then subsequent API calls use a lightweight reference to that cached content, dramatically reducing the token count for each message.
* Break down your requests: If your task can be broken into smaller parts, consider making multiple, smaller API calls instead of one large one.
Since the error has persisted for four days, it’s likely that your application is repeatedly attempting to send the same oversized request. You need to identify where in your app the large input is being generated and implement one or more of the strategies above to reduce its size.