feat: allow max context length

[ParkerSm1th]

Summary

• Added the ability to optionally pass in maxContextLength to Agent

This is a feature that existed in LangChain + LangSmith workflow, allowing for a sticky systemMessage (instructions in Mastra terms). Adding this allows for devs to utilize this without having to self implement

Tests Added

• Added unit tests

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🦋 Changeset detected

Latest commit: 93c3df4

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 46 packages

Name	Type
@mastra/core	Patch
mastra	Patch
@mastra/deployer	Patch
@mastra/evals	Patch
@mastra/loggers	Patch
@mastra/mcp	Patch
@mastra/memory	Patch
@mastra/rag	Patch
@mastra/deployer-cloudflare	Patch
@mastra/deployer-netlify	Patch
@mastra/deployer-vercel	Patch
@mastra/astra	Patch
@mastra/chroma	Patch
@mastra/pg	Patch
@mastra/pinecone	Patch
@mastra/qdrant	Patch
@mastra/upstash	Patch
@mastra/vectorize	Patch
@mastra/speech-azure	Patch
@mastra/speech-deepgram	Patch
@mastra/speech-elevenlabs	Patch
@mastra/speech-google	Patch
@mastra/speech-ibm	Patch
@mastra/speech-murf	Patch
@mastra/speech-openai	Patch
@mastra/speech-playai	Patch
@mastra/speech-replicate	Patch
@mastra/speech-speechify	Patch
@mastra/voice-deepgram	Patch
@mastra/voice-elevenlabs	Patch
@mastra/voice-google	Patch
@mastra/voice-murf	Patch
@mastra/voice-openai	Patch
@mastra/voice-playai	Patch
@mastra/voice-speechify	Patch
@mastra/client-js	Patch
@mastra/composio	Patch
@mastra/firecrawl	Patch
@mastra/github	Patch
@mastra/ragie	Patch
@mastra/stabilityai	Patch
mastra-ai-sdk-use-chat-example	Patch
memory-todo-agent	Patch
voice-agent	Patch
insert-embedding-in-libsql	Patch
insert-embedding-in-chroma	Patch

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[dennis-magical]

This would be super helpful for us

[wardpeet]

I'm not sure we should add it. Shouldn't we throw an error instead that the message got to big? If we cut the message from the start, we might not get the expected result.

[abhiaiyer91]

Ah i understand now, this trims the context between System (instructions) and user prompt.

[wardpeet]

Ok i misread it, it's just context being sliced. Let's remove the dynamic function.

Thank you for contributing!

[wardpeet]

Let's remove dynamic updatinhg of max length for now

Suggested change

	__updateMaxContextLength(newMaxContextLength: number) {
	this.maxContextLength = newMaxContextLength;
	this.logger.debug(`[Agents:${this.name}] Max context length updated.`, {
	model: this.model,
	name: this.name,
	});
	}