Letta alternatives

Letta is listed under Agents: Agent runtime with persistent memory, from the MemGPT project. We compare it with 15 other Agents tools that have researched data. 15 of them offer a free plan or are free to use (6 open source), and 0 are paid only. Letta itself is freemium (free plan + paid tiers).

Order: Sorted by how much you can use for free (free or open source first, then free plan with paid tiers, then paid only), then by the number of documented features, then alphabetically. No ratings or reviews are used.

Tool	Pricing	Free tier	Key features	Who it's for
Letta this tool	Freemium (free plan + paid tiers) Paid plans from $20/month	Yes	Stateful agents that remember and continue learning Store agent memory in git-based context repositories Let agents reason about context during idle time	Individuals, teams, and developers who use or build stateful AI agents.
Agensh	Free and open source	Yes	Agents discover and claim sub-tasks, share findings, verify results, and merge progress Runs without a central orchestrator, using a shared workspace, messages, and shared context Published experiments scale the harness to 1,024 agents	Engineers reproducing a self-organized multi-agent harness on one machine.
Omnara	Freemium (free plan + paid tiers) Platform fee $0; pay as you go for models and machines	Yes	Runs agents through one REST API, a TypeScript SDK, and a CLI Uses OpenAI, Anthropic, OpenRouter, LiteLLM, or a model you host Runs agents on sandboxes or on your own macOS or Linux machine	Teams who want to run production agents on their own models and machines.
Dust	Freemium (free plan + paid tiers) Paid plans from 30€/seat/month	Yes	Connect agents to Slack, Notion, Drive, GitHub, Salesforce, and Zendesk Choose among 20+ models for each workflow Run multi-agent workflows on schedules and event triggers	Company teams that create, share, and run AI agents across their workflows.
Mastra	Freemium (free plan + paid tiers) Paid plans from $250/month	Yes	Define typed agents with instructions, models, and tools Compose multi-step workflows with retries and branches Store context using observational memory and semantic recall	Developers and teams building AI agents and applications in TypeScript.
Harness²	Free and open source	Yes	Task-level recursion proposes edits, probes them on the same task, and composes a harness Harnessing-level recursion keeps adopted harnesses and lessons for the next task Eight editable parts: system prompt, guardrails, memory, tool guidance, subagents, skills, scripts, and plugins	Engineers refining an agent harness for tasks unseen when that harness was designed.
LearnHarness	Free and open source	Yes	Measures where understanding ends, then plans a dependency map from there to the goal Teaches one reasoning step at a time, then runs separate practice sessions Stores propositions and reasoning chains in a knowledge graph across sessions	People who want an agent to teach a subject from what they already understand.
OpenShell	Free and open source	Yes	Runs each agent in an isolated sandbox Confines files and system calls with kernel controls inside the sandbox Checks every network connection against policy before it leaves the sandbox	Teams that run fleets of autonomous agents and want policy on files, network, and credentials.
ESP32 iPhone Agent	Free and open source	Yes	Mirrors the iPhone screen over AirPlay into JPEG frames Controls the phone with an ESP32-S3 USB mouse and keyboard Uses any OpenAI-compatible vision model, cloud or local	People who want an AI model to operate a real iPhone.
Haystack	Free and open source	Yes	Wire retrieval, reasoning, memory, and tools into agent flows Plug in OpenAI, Anthropic, Mistral, Hugging Face, and vector databases Run serializable pipelines on Kubernetes with logging and monitoring	Teams and developers building LLM-powered agents and NLP applications.
Alter	Freemium (free plan + paid tiers) Free: 10,000 calls/mo; Starter $50/mo	Yes	Stores credentials in a vault and injects them per request Checks each call against a default-deny policy Gives each agent its own identity and scopes	Teams that need to control what AI agents can do with user credentials.
Agno	Freemium (free plan + paid tiers) Paid plans from $150/month	Yes	Build agents, teams, and workflows using 100+ toolkits Expose agents as a product API or MCP server Run the platform in any cloud, on-prem, or locally	Engineers and teams who build customer-facing and internal agents in their own cloud.
Browser Use	Freemium (free plan + paid tiers) Credits from $5	Yes	Remote browsers for agents via SDK, REST, or CDP Hosted agents that complete browser tasks MIT-licensed code you can run on your machine	For AI startups and automation teams that run browser agents.
Browserbase	Freemium (free plan + paid tiers) Paid plans from $20/month	Yes	Cloud browsers agents can drive to use websites Search for sites from a single query Fetch any URL as HTML, JSON, or markdown	Developers and companies building agents that browse and act on the web.
Composio	Freemium (free plan + paid tiers)	Yes	Gives agents access to more than 1,500 apps Loads only the catalog actions a task needs Manages OAuth sign-in and per-account scopes	Developers and teams connecting AI agents and assistants to work apps.
CrewAI	Freemium (free plan + paid tiers)	Yes	Ranks automations from tickets, chats, apps, and workflows Visual editor builds workflows and exports them to Python Traces LLM calls, tool calls, and memory reads with costs	Business teams, engineers, and platform teams that build and govern agents.

Letta alternatives: FAQ

What are the best Letta alternatives?

Agensh, Omnara, Dust, Mastra, Harness², LearnHarness, OpenShell, ESP32 iPhone Agent, Haystack, Alter, Agno, Browser Use, Browserbase, Composio, CrewAI are the Letta alternatives in our directory that have researched data. They are ordered by how much you can use for free, then by documented features. No ratings or reviews are used, so the order is not a quality ranking.

Is there a free alternative to Letta?

Agensh (free and open source), Omnara (freemium (free plan + paid tiers)), Dust (freemium (free plan + paid tiers)), Mastra (freemium (free plan + paid tiers)), Harness² (free and open source), LearnHarness (free and open source), OpenShell (free and open source), ESP32 iPhone Agent (free and open source), Haystack (free and open source), Alter (freemium (free plan + paid tiers)), Agno (freemium (free plan + paid tiers)), Browser Use (freemium (free plan + paid tiers)), Browserbase (freemium (free plan + paid tiers)), Composio (freemium (free plan + paid tiers)), CrewAI (freemium (free plan + paid tiers)). Free tiers can change, so check each site.