Letta vs Mastra (2026): which should you pick?
As of Nov 12, 2026, Mastra grades higher than Letta: 2.8 against 2.0 out of 4.0.
Checked Nov 12, 2026 · graded Nov 12, 2026 by ToolGPA
Mastra grades higher on value for money, the free plan and features. They get the same grade on ease of use and platforms.
Price, platforms and features side by side. The table says where each price was read and when.
Letta
Stateful agents with long-term memory, from the MemGPT team
Mastra
TypeScript framework for building and running AI agents
Which one is for you
Pick Letta if
- Fits if you are a developer who wants agents that keep their memory between runs
- Works for people who already pay for a coding plan and can bring that key
Look elsewhere if
- Tight if you stay free, because there is no included model usage and 3 agents is the cap
- Pricey if you code heavily, as the pricing page says $100 to $200 a month or more of usage
- Watch out: server tool time is billed at $0.00015 a second against your credits
- Watch out: more than one person needs Teams Pro, since Pro covers a single user
Pick Mastra if
- Fits if you write TypeScript and want to build your own agents
- Works for teams that want to deploy agents on Vercel or Cloudflare
Look elsewhere if
- Not for you if you want no-code, since building an agent means writing TypeScript
- Pricey if you grow, as past the allowance egress is $0.10 a GB and events $10 per 100K
- Watch out: RBAC, SSO and audit logs are Enterprise only, and the SOC 2 report starts at Team at $250
- Watch out: some repository folders (ee/) sit under a separate enterprise licence
How we grade them
| 2.0GPALettaFair | 2.8GPAMastraGood | |
|---|---|---|
| Value for money | CPro is $20 a month with $20 of credits, around the category's $21 middle. Teams Pro is $20 a seat. | AThe framework is open source and the cloud has a free plan. Starter is $25 a workspace a month and Team $250. |
| Free plan and trial | CFree covers 3 stateful agents but no model usage, so you bring your own keys or buy credits. | BFree cloud plan: unlimited agents, users and deployments, 100K observability events and 15-day trace retention. A solo developer can live on that. |
| Features | CPersistent memory, a coding CLI, an SDK, and Slack and GitHub channels. Memory repositories are capped at 5 MiB on Free, and web search and tools spend credits. | BAgents, workflows, memory, evals, MCP servers and deployment to many hosts. Nothing in the listing is missing for code-first agent work. |
| Ease of use | DNo store rating, and the main route is an npm-installed CLI and SDK, so you work from a command line. | DNo store rating, and building an agent means writing TypeScript and running it yourself. |
| Platforms and integrations | BWeb plus a CLI and SDK, with Slack, GitHub, Telegram, Discord, WhatsApp and Signal channels. | BWeb with deployment to Vercel, Netlify and Cloudflare, and Next.js, React, Hono and Express listed. |
| Best for | developers building agents that remember across sessions | TypeScript developers building their own agents |
The GPA is the average of the five grades: an A is 4 points, an F is none. The full reasons are on each tool's page: Letta and Mastra. How we grade
Price against what you get
Letta starts at $20 a month and scores 2.0 out of 4 on features, ease of use and platforms. Mastra starts at $25 a month and scores 2.3.
Mastra scores higher, and starts $5 a month higher: the question is whether the extra is worth that to you. Of the other AI agents on the chart, 17 score higher than Letta for less, and 20 score higher than Mastra for less.
Features, ease of use and platforms, averaged
What paid plans start at, a month (each step along is roughly double) →
- The best score at each price
- Has a free plan
- No free plan
Where they differ
- Mastra is self-hostable, according to its own site.
At a glance
| Letta | Mastra | |
|---|---|---|
| Pricing | Free plan | Free plan |
| Starts at | $20 per month | $25 per workspace / month |
| Free plan | Up to 3 stateful agents and 5 MiB per memory repository; bring your own API keys or an external coding plan. | Unlimited agents, users and deployments, 100K observability events, 1 GB egress, 5 connections and 15-day trace retention. |
| Free trial | None listed | None listed |
| Web | ||
| Made by | Letta, Inc. | Mastra |
| Price read from | docs.letta.com | mastra.ai |
| Checked | Nov 12, 2026 | Nov 12, 2026 |
Worth knowing
Letta
- The free plan has no included model usage; you bring your own keys or buy credits.
- Credits are spent by model usage at provider-based rates, and the pricing page says heavy coding use can run $100 to $200 a month or more.
- Server-side tool time is billed at $0.00015 per second against credits, and web search and fetch tools also cost credits.
- Adding members to an organization needs Teams Pro; Pro covers a single user.
Mastra
- It is a code framework, so building an agent means writing TypeScript; there is no no-code builder.
- Cloud usage past each plan's allowance is billed separately, for example $0.10 per GB of egress and $10 per 100K observability events.
- RBAC, SSO and audit logs are Enterprise only, and the SOC 2 report starts at the Team plan.
- Some directories in the repository are under a separate enterprise license (ee/), so not every file carries the main open-source terms.
Key features
Letta
- Persistent agent memory
- Agents are stateful: they carry memory across sessions, and memory repositories are versioned in git so changes can be tracked.
- Letta Code CLI
- An open-source harness installed with npm for coding agents, personal assistants and agents that work on local files, with skills and schedules.
- Agent SDK and app server
- Developers can embed stateful agents in their own applications, with a self-hosting option and a protocol for external tools.
- Channels and cloud agents
- Cloud-hosted agents connect to Slack and a GitHub integration; the channels guide also lists Telegram, Discord, WhatsApp and Signal.
- Bring your own keys
- All plans accept your own model API keys, and usage then goes through your provider account instead of using Letta credits.
Mastra
- Agents
- Typed agents are defined in code with instructions, a model, tools and runtime behavior in one place.
- Workflows
- Typed steps can be chained with retries and branches into workflows that a team can inspect.
- Memory
- Agents can keep durable context through thread-aware storage, semantic recall and an observational memory option.
- Observability and evals
- Traces, metrics and logs sit alongside evaluation tools such as scorers, datasets and experiments.
- MCP servers
- Agents, tools and other resources can be exposed as Model Context Protocol servers that any MCP-capable system can call.
- Deploy anywhere
- A Mastra app runs on any Node.js host or as a standalone server, with optional deployers for Vercel, Netlify and Cloudflare, or on Mastra Cloud.
Plans
Letta
Free$0
per month
Up to 3 stateful agents; no included model usage, so bring your own keys or buy credits.
Pro$20
per month
Includes $20 of credits a month for any model and remote sandboxes, up to 20 stateful agents.
Teams Pro$20
per seat / month
Everything in Pro, plus teammates in an organization, shared agents and access control.
EnterpriseCustom
Volume-based pricing with role-based access control, SAML/OIDC SSO and dedicated support.
Mastra
Free$0
Unlimited agents, users and deployments, 100K observability events, 1 GB egress, 5 connections and 15-day trace retention.
Starter$25
per workspace / month
One small dedicated project, usage alerts, 250K observability events, 10 GB egress, 10 connections and 60-day trace retention.
Team$250
per workspace / month
One small and two medium dedicated projects, a SOC 2 report, 10M observability events, 100 GB egress, 50 connections and 180-day trace retention.
EnterpriseCustom
RBAC, SSO, audit logs, custom allowances and connections, and dedicated support.
Common questions
Which is cheaper, Letta or Mastra?
As of Nov 12, 2026, Letta is cheaper to start with: $20 a month, against $25 a month for Mastra. Letta starts at $20 per month, and Mastra starts at $25 per workspace / month.
Which has a free plan, Letta or Mastra?
As of Nov 12, 2026, both Letta and Mastra have a free plan.
More comparisons
How this page was made
- The verdict at the top follows a fixed rule. When both tools are in the same category and either is in our top three for it, the verdict follows that ranking: the higher-placed tool is our pick. The top three weigh who each tool suits as well as its grades, so a pick can go against the GPA. Otherwise the page does not pick one and says which grades higher: the higher GPA first; on a tie, the one with a free plan, then the one that starts cheaper in dollars a month, counted the same way for both; if they are still level, what the choice depends on.
- The grades are our own, from each tool’s review or report card. The GPA is their average.
- Prices, plans and platforms come from each tool’s listing. The table above says where each price was read and when.
- The differences and the answers to the questions are worked out from those listings.