CLI Commands
You can use the Command-Line Interface (CLI) provided by Mastra to develop, build, and start your Mastra project.
mastra devDirect link to mastra-dev
Starts a server which exposes Studio and REST endpoints for your agents, tools, and workflows. You can visit http://localhost:4111/swagger-ui for an overview of all available endpoints once mastra dev is running.
You can also configure the server.
FlagsDirect link to Flags
The command accepts common flags and the following additional flags:
--httpsDirect link to --https
Enable local HTTPS support. Learn more.
--inspectDirect link to --inspect
Start the development server in inspect mode, helpful for debugging. Optionally specify a custom host and port (e.g., --inspect=0.0.0.0:9229 for Docker). This can't be used together with --inspect-brk.
--inspect-brkDirect link to --inspect-brk
Start the development server in inspect mode and break at the beginning of the script. Optionally specify a custom host and port (e.g., --inspect-brk=0.0.0.0:9229). This can't be used together with --inspect.
--custom-argsDirect link to --custom-args
Comma-separated list of custom arguments to pass to the development server. You can pass arguments to the Node.js process, e.g. --experimental-transform-types.
ConfigsDirect link to Configs
You can set certain environment variables to modify the behavior of mastra dev.
Disable build cachingDirect link to Disable build caching
Set MASTRA_DEV_NO_CACHE=1 to force a full rebuild rather than using the cached assets under .mastra/:
MASTRA_DEV_NO_CACHE=1 mastra dev
This helps when you are debugging bundler plugins or suspect stale output.
Limit parallelismDirect link to Limit parallelism
MASTRA_CONCURRENCY caps how many expensive operations run in parallel (primarily build and evaluation steps). For example:
MASTRA_CONCURRENCY=4 mastra dev
Leave it unset to let the CLI pick a sensible default for the machine.
Custom provider endpointsDirect link to Custom provider endpoints
When using providers supported by the Vercel AI SDK you can redirect requests through proxies or internal gateways by setting a base URL. For OpenAI:
OPENAI_API_KEY=<your-api-key> \
OPENAI_BASE_URL=https://openrouter.example/v1 \
mastra dev
For Anthropic:
ANTHROPIC_API_KEY=<your-api-key> \
ANTHROPIC_BASE_URL=https://anthropic.internal \
mastra dev
These are forwarded to the Mastra model router and will work with any "openai/..."
or "anthropic/..." model selections.
mastra buildDirect link to mastra-build
The mastra build command bundles your Mastra project into a production-ready Hono server. Hono is a lightweight, type-safe web framework that makes it easy to deploy Mastra agents as HTTP endpoints with middleware support.
Under the hood Mastra's Rollup server locates your Mastra entry file and bundles it to a production-ready Hono server. During that bundling it tree-shakes your code and generates source maps for debugging.
The output in .mastra can be deployed to any cloud server using mastra start.
If you're deploying to a serverless platform you need to install the correct deployer in order to receive the correct output in .mastra.
It accepts common flags.
ConfigsDirect link to Configs
You can set certain environment variables to modify the behavior of mastra build.
Limit parallelismDirect link to Limit parallelism
For CI or when running in resource constrained environments you can cap how many expensive tasks run at once by setting MASTRA_CONCURRENCY.
MASTRA_CONCURRENCY=2 mastra build
mastra startDirect link to mastra-start
You need to run mastra build before using mastra start.
Starts a local server to serve your built Mastra application in production mode. By default, OTEL Tracing is enabled.
FlagsDirect link to Flags
The command accepts common flags and the following additional flags:
--dirDirect link to --dir
The path to your built Mastra output directory. Defaults to .mastra/output.
--no-telemetryDirect link to --no-telemetry
Disable the OTEL Tracing.
mastra studioDirect link to mastra-studio
Starts Mastra Studio as a static server. After starting, you can enter your Mastra instance URL (e.g. http://localhost:4111) to connect Studio to your Mastra backend.
FlagsDirect link to Flags
The command accepts common flags and the following additional flags:
--portDirect link to --port
The port to run Studio on. Defaults to 3000.
mastra lintDirect link to mastra-lint
The mastra lint command validates the structure and code of your Mastra project to ensure it follows best practices and is error-free.
It accepts common flags.
mastra scorersDirect link to mastra-scorers
The mastra scorers command provides management capabilities for evaluation scorers that measure the quality, accuracy, and performance of AI-generated outputs.
Read the Scorers overview to learn more.
addDirect link to add
Add a new scorer to your project. You can use an interactive prompt:
mastra scorers add
Or provide a scorer name directly:
mastra scorers add answer-relevancy
Use the list command to get the correct ID.
listDirect link to list
List all available scorer templates. Use the ID for the add command.
mastra initDirect link to mastra-init
The mastra init command initializes Mastra in an existing project. Use this command to scaffold the necessary folders and configuration without generating a new project from scratch.
FlagsDirect link to Flags
The command accepts the following additional flags:
--defaultDirect link to --default
Creates files inside src using OpenAI. It also populates the src/mastra folders with example code.
--dirDirect link to --dir-1
The directory where Mastra files should be saved to. Defaults to src.
--componentsDirect link to --components
Comma-separated list of components to add. For each component a new folder will be created. Choose from: "agents" | "tools" | "workflows" | "scorers". Defaults to ['agents', 'tools', 'workflows'].
--llmDirect link to --llm
Default model provider. Choose from: "openai" | "anthropic" | "groq" | "google" | "cerebras" | "mistral".
--llm-api-keyDirect link to --llm-api-key
The API key for your chosen model provider. Will be written to an environment variables file (.env).
--exampleDirect link to --example
If enabled, example code is written to the list of components (e.g. example agent code).
--no-exampleDirect link to --no-example
Do not include example code. Useful when using the --default flag.
--mcpDirect link to --mcp
Configure your code editor with Mastra's MCP server. Choose from: "cursor" | "cursor-global" | "windsurf" | "vscode".
Common flagsDirect link to Common flags
--dirDirect link to --dir-2
Available in: dev, build, lint
The path to your Mastra folder. Defaults to src/mastra.
--debugDirect link to --debug
Available in: dev, build
Enable verbose logging for Mastra's internals. Defaults to false.
--envDirect link to --env
Available in: dev, start, studio
Custom environment variables file to include. By default, includes .env.development, .env.local, and .env.
--rootDirect link to --root
Available in: dev, build, lint
Path to your root folder. Defaults to process.cwd().
--toolsDirect link to --tools
Available in: dev, build, lint
Comma-separated list of tool paths to include. Defaults to src/mastra/tools.
Global flagsDirect link to Global flags
Use these flags to get information about the mastra CLI.
--versionDirect link to --version
Prints the Mastra CLI version and exits.
--helpDirect link to --help
Prints help message and exits.
TelemetryDirect link to Telemetry
By default, Mastra collects anonymous information about your project like your OS, Mastra version or Node.js version. You can read the source code to check what's collected.
You can opt out of the CLI analytics by setting an environment variable:
MASTRA_TELEMETRY_DISABLED=1
You can also set this while using other mastra commands:
MASTRA_TELEMETRY_DISABLED=1 mastra dev