fastmcp API reference

400 public APIs from fastmcp (PrefectHQ/fastmcp) — 152 classes, 97 functions, 151 methods. Signatures extracted by static analysis of the actual source.

Repository: PrefectHQ/fastmcp

Kind	Count
Classes	152
Functions	97
Methods	151

API list

classfastmcp_slim.fastmcp._warnings.FastMCPDeprecationWarning

Deprecation warning for FastMCP APIs.

classfastmcp_slim.fastmcp.apps.app.FastMCPApp

A Provider that represents an MCP application.

methodfastmcp_slim.fastmcp.apps.app.FastMCPApp.add_tool(tool:Tool | Callable[..., Any]) -> Tool

Add a tool to this app programmatically.

funcfastmcp_slim.fastmcp.apps.choice.Choice.choose(prompt:str, options:list[str], title:str | None=None) -> PrefabApp

Present the user with a set of options to choose from.

classfastmcp_slim.fastmcp.apps.config.AppConfig

Configuration for MCP App tools and resources.

classfastmcp_slim.fastmcp.apps.config.ResourceCSP

Content Security Policy for MCP App resources.

classfastmcp_slim.fastmcp.apps.config.ResourcePermissions

Iframe sandbox permissions for MCP App resources.

funcfastmcp_slim.fastmcp.apps.file_upload.FileUpload.file_manager(ctx:Context) -> PrefabApp

Upload and manage files.

funcfastmcp_slim.fastmcp.apps.file_upload.FileUpload.list_files(ctx:Context) -> list[dict]

List all uploaded files with metadata.

methodfastmcp_slim.fastmcp.apps.file_upload.FileUpload.on_list(ctx:Context) -> list[dict[str, Any]]

List all stored files.

methodfastmcp_slim.fastmcp.apps.file_upload.FileUpload.on_read(name:str, ctx:Context) -> dict[str, Any]

Read a file's contents by name.

method

fastmcp_slim.fastmcp.apps.file_upload.FileUpload.on_store(files:list[dict[str, Any]], ctx:Context) -> list[dict[str, Any]]

Store uploaded files and return summaries.

funcfastmcp_slim.fastmcp.apps.file_upload.FileUpload.read_file(name:str, ctx:Context) -> dict

Read an uploaded file's contents by name.

funcfastmcp_slim.fastmcp.apps.file_upload.FileUpload.store_files(files:list[dict], ctx:Context) -> list[dict]

Store uploaded files.

func

fastmcp_slim.fastmcp.apps.form.FormInput.collect_input(prompt:str, title:str | None=None, submit_text:str | None=None, default:dict[str, Any] | None=None) -> PrefabApp

Collect structured input from the user.

funcfastmcp_slim.fastmcp.apps.form.FormInput.submit_form(data:dict[str, Any] | None=None) -> str

Validate and process form submission.

funcfastmcp_slim.fastmcp.cli.apps_dev.api_logs(request:Request) -> Response

Return message log entries since a given id.

funcfastmcp_slim.fastmcp.cli.apps_dev.api_logs_clear(request:Request) -> Response

Clear the message log.

funcfastmcp_slim.fastmcp.cli.apps_dev.launch(request:Request) -> HTMLResponse

Host page: GET /launch?tool=name&args={...}

funcfastmcp_slim.fastmcp.cli.apps_dev.picker_app(request:Request) -> HTMLResponse

Prefab picker UI — tool list with one tab per UI tool.

funcfastmcp_slim.fastmcp.cli.apps_dev.serve_app_bridge_js(request:Request) -> Response

Serve the locally patched app-bridge.js.

funcfastmcp_slim.fastmcp.cli.apps_dev.ui_resource(request:Request) -> Response

Fetch an MCP resource server-side and return it as HTML.

funcfastmcp_slim.fastmcp.cli.cli.with_argv(args:list[str] | None)

Temporarily replace sys.argv if args provided.

funcfastmcp_slim.fastmcp.cli.client.coerce_value(raw:str, schema:dict[str, Any]) -> Any

Coerce a string CLI value according to a JSON-Schema type hint.

methodfastmcp_slim.fastmcp.cli.discovery.DiscoveredServer.qualified_name() -> str

Fully qualified ``source:name`` identifier.

funcfastmcp_slim.fastmcp.cli.discovery.discover_servers(start_dir:Path | None=None) -> list[DiscoveredServer]

Run all scanners and return the combined results.

func

fastmcp_slim.fastmcp.cli.generate.generate_cli_script(server_name:str, server_spec:str, transport_code:str, extra_imports:set[str], tools:list[mcp_types.Tool]) -> str

Generate the full CLI script source code.

funcfastmcp_slim.fastmcp.cli.install.claude_code.check_claude_code_available() -> bool

Check if Claude Code CLI is available.

funcfastmcp_slim.fastmcp.cli.install.claude_code.find_claude_command() -> str | None

Find the Claude Code CLI command.

funcfastmcp_slim.fastmcp.cli.install.claude_desktop.get_claude_config_path(config_path:Path | None=None) -> Path | None

Get the Claude config directory based on platform.

funcfastmcp_slim.fastmcp.cli.install.gemini_cli.check_gemini_cli_available() -> bool

Check if Gemini CLI is available.

funcfastmcp_slim.fastmcp.cli.install.gemini_cli.find_gemini_command() -> str | None

Find the Gemini CLI command.

funcfastmcp_slim.fastmcp.cli.install.shared.parse_env_var(env_var:str) -> tuple[str, str]

Parse environment variable string in format KEY=VALUE.

funcfastmcp_slim.fastmcp.cli.run.create_client_server(url:str) -> Any

Create a FastMCP server from a client URL.

funcfastmcp_slim.fastmcp.cli.run.create_mcp_config_server(mcp_config_path:Path) -> FastMCP[None]

Create a FastMCP server from a MCPConfig.

funcfastmcp_slim.fastmcp.cli.run.is_url(path:str) -> bool

Check if a string is a URL.

funcfastmcp_slim.fastmcp.cli.run.load_mcp_server_config(config_path:Path) -> MCPServerConfig

Load a FastMCP configuration from a fastmcp.json file.

func

fastmcp_slim.fastmcp.cli.run.run_v1_server_async(server:SDKServer, host:str | None=None, port:int | None=None, transport:TransportType | None=None) -> None

Run a FastMCP 1.x server using async methods.

func

fastmcp_slim.fastmcp.cli.run.run_with_reload(cmd:list[str], reload_dirs:list[Path] | None=None, is_stdio:bool=False) -> None

Run a command with file watching and auto-reload.

classfastmcp_slim.fastmcp.client.client.CallToolResult

Parsed result from a tool call.

methodfastmcp_slim.fastmcp.client.client.Client.cancel(request_id:str | int, reason:str | None=None) -> None

Send a cancellation notification for an in-progress request.

method

fastmcp_slim.fastmcp.client.client.Client.initialize(timeout:datetime.timedelta | float | int | None=None) -> mcp_types.InitializeResult

Send an initialize request to the server.

methodfastmcp_slim.fastmcp.client.client.Client.is_connected() -> bool

Check if the client is currently connected.

methodfastmcp_slim.fastmcp.client.client.Client.ping() -> bool

Send a ping request.

method

fastmcp_slim.fastmcp.client.client.Client.progress(progress_token:str | int, progress:float, total:float | None=None, message:str | None=None) -> None

Send a progress notification.

methodfastmcp_slim.fastmcp.client.client.Client.send_roots_list_changed() -> None

Send a roots/list_changed notification.

methodfastmcp_slim.fastmcp.client.client.Client.session() -> ClientSession

Get the current active session.

methodfastmcp_slim.fastmcp.client.client.Client.set_elicitation_callback(elicitation_callback:ElicitationHandler) -> None

Set the elicitation callback for the client.

methodfastmcp_slim.fastmcp.client.client.Client.set_logging_level(level:mcp_types.LoggingLevel) -> None

Send a logging/setLevel request.

methodfastmcp_slim.fastmcp.client.client.Client.set_roots(roots:RootsList | RootsHandler) -> None

Set the roots for the client.

classfastmcp_slim.fastmcp.client.mixins.prompts.ClientPromptsMixin

Mixin providing prompt-related methods for Client.

classfastmcp_slim.fastmcp.client.mixins.tools.ClientToolsMixin

Mixin providing tool-related methods for Client.

method

fastmcp_slim.fastmcp.client.mixins.tools.ClientToolsMixin.list_tools(max_pages:int=AUTO_PAGINATION_MAX_PAGES) -> list[mcp_types.Tool]

Retrieve all tools available on the server.

func

fastmcp_slim.fastmcp.client.progress.default_progress_handler(progress:float, total:float | None, message:str | None) -> None

Default handler for progress notifications.

classfastmcp_slim.fastmcp.client.sampling.handlers.openai.OpenAISamplingHandler

Sampling handler that uses the OpenAI API.

classfastmcp_slim.fastmcp.client.transports.base.TransportOptions

How one client wants its connection built.

classfastmcp_slim.fastmcp.client.transports.memory.FastMCPTransport

In-memory transport for FastMCP servers.

classfastmcp_slim.fastmcp.client.transports.stdio.NodeStdioTransport

Transport for running Node.js scripts.

classfastmcp_slim.fastmcp.client.transports.stdio.NpxStdioTransport

Transport for running commands via the npx tool.

classfastmcp_slim.fastmcp.client.transports.stdio.PythonStdioTransport

Transport for running Python scripts.

classfastmcp_slim.fastmcp.client.transports.stdio.UvStdioTransport

Transport for running commands via the uv tool.

classfastmcp_slim.fastmcp.client.transports.stdio.UvxStdioTransport

Transport for running commands via the uvx tool.

funcfastmcp_slim.fastmcp.contrib.bulk_tool_caller.example.echo_tool(text:str) -> str

Echo the input text

funcfastmcp_slim.fastmcp.contrib.component_manager.example.get_greeting() -> str

Provides a simple greeting message.

funcfastmcp_slim.fastmcp.contrib.component_manager.example.get_info() -> str

Provides a simple info.

methodfastmcp_slim.fastmcp.contrib.mcp_mixin.example.Sample.first_prompt()

First prompt description.

methodfastmcp_slim.fastmcp.contrib.mcp_mixin.example.Sample.first_resource()

First resource description.

methodfastmcp_slim.fastmcp.contrib.mcp_mixin.example.Sample.first_tool()

First tool description.

classfastmcp_slim.fastmcp.decorators.HasFastMCPMeta

Protocol for callables decorated with FastMCP metadata.

funcfastmcp_slim.fastmcp.decorators.resolve_task_config(task:bool | TaskConfig | None) -> bool | TaskConfig

Resolve task config, defaulting None to False.

classfastmcp_slim.fastmcp.exceptions.AuthorizationError

Error when authorization check fails.

classfastmcp_slim.fastmcp.exceptions.ClientError

Error in client operations.

classfastmcp_slim.fastmcp.exceptions.DisabledError

Object is disabled.

classfastmcp_slim.fastmcp.exceptions.FastMCPError

Base error for FastMCP.

classfastmcp_slim.fastmcp.exceptions.InvalidSignature

Invalid signature for use with FastMCP.

classfastmcp_slim.fastmcp.exceptions.MCPError

Fallback used when MCP dependencies are not installed.

classfastmcp_slim.fastmcp.exceptions.NotFoundError

Object not found.

classfastmcp_slim.fastmcp.exceptions.PromptError

Error in prompt operations.

classfastmcp_slim.fastmcp.exceptions.ResourceError

Error in resource operations.

classfastmcp_slim.fastmcp.exceptions.ToolError

Error in tool operations.

classfastmcp_slim.fastmcp.exceptions.ValidationError

Error in validating parameters or return values.

classfastmcp_slim.fastmcp.experimental.transforms.code_mode.MontySandboxProvider

Sandbox provider backed by `pydantic-monty`.

classfastmcp_slim.fastmcp.mcp_config.CanonicalMCPConfig

Canonical MCP configuration format.

methodfastmcp_slim.fastmcp.mcp_config.CanonicalMCPConfig.add_server(name:str, server:CanonicalMCPServerTypes) -> None

Add or update a server in the configuration.

methodfastmcp_slim.fastmcp.mcp_config.MCPConfig.add_server(name:str, server:MCPServerTypes) -> None

Add or update a server in the configuration.

methodfastmcp_slim.fastmcp.mcp_config.MCPConfig.from_dict(config:dict[str, Any]) -> Self

Parse MCP configuration from dictionary format.

methodfastmcp_slim.fastmcp.mcp_config.MCPConfig.from_file(file_path:Path) -> Self

Load configuration from JSON file.

methodfastmcp_slim.fastmcp.mcp_config.MCPConfig.write_to_file(file_path:Path) -> None

Write configuration to JSON file.

classfastmcp_slim.fastmcp.mcp_config.RemoteMCPServer

MCP server configuration for HTTP/SSE transport.

classfastmcp_slim.fastmcp.mcp_config.StdioMCPServer

MCP server configuration for stdio transport.

classfastmcp_slim.fastmcp.mcp_config.TransformingRemoteMCPServer

A Remote server with tool transforms.

classfastmcp_slim.fastmcp.mcp_config.TransformingStdioMCPServer

A Stdio server with tool transforms.

funcfastmcp_slim.fastmcp.mcp_config.infer_transport_type_from_url(url:str | AnyUrl) -> Literal['http', 'sse']

Infer the appropriate transport type from the given URL.

classfastmcp_slim.fastmcp.prompts.base.Message

Wrapper for prompt message with auto-serialization.

methodfastmcp_slim.fastmcp.prompts.base.Message.to_mcp_prompt_message() -> PromptMessage

Convert to MCP PromptMessage.

classfastmcp_slim.fastmcp.prompts.base.Prompt

A prompt template that can be rendered with parameters.

methodfastmcp_slim.fastmcp.prompts.base.Prompt.convert_result(raw_value:Any) -> PromptResult

Convert a raw return value to PromptResult.

method

fastmcp_slim.fastmcp.prompts.base.Prompt.render(arguments:dict[str, Any] | None=None) -> str | list[Message | str] | PromptResult

Render the prompt with arguments.

methodfastmcp_slim.fastmcp.prompts.base.Prompt.to_mcp_prompt(**overrides:Any) -> SDKPrompt

Convert the prompt to an MCP prompt.

classfastmcp_slim.fastmcp.prompts.base.PromptArgument

An argument that can be passed to a prompt.

classfastmcp_slim.fastmcp.prompts.base.PromptResult

Canonical result type for prompt rendering.

methodfastmcp_slim.fastmcp.prompts.base.PromptResult.to_mcp_prompt_result() -> GetPromptResult

Convert to MCP GetPromptResult.

classfastmcp_slim.fastmcp.prompts.function_prompt.DecoratedPrompt

Protocol for functions decorated with @prompt.

classfastmcp_slim.fastmcp.prompts.function_prompt.FunctionPrompt

A prompt that is a function.

methodfastmcp_slim.fastmcp.prompts.function_prompt.FunctionPrompt.render(arguments:dict[str, Any] | None=None) -> PromptResult

Render the prompt with arguments.

classfastmcp_slim.fastmcp.resources.base.Resource

Base class for all resources.

methodfastmcp_slim.fastmcp.resources.base.Resource.convert_result(raw_value:Any) -> ResourceResult

Convert a raw result to ResourceResult.

methodfastmcp_slim.fastmcp.resources.base.Resource.key() -> str

The globally unique lookup key for this resource.

methodfastmcp_slim.fastmcp.resources.base.Resource.read() -> str | bytes | ResourceResult

Read the resource content.

methodfastmcp_slim.fastmcp.resources.base.Resource.set_default_mime_type(mime_type:str | None) -> str

Set default MIME type if not provided.

methodfastmcp_slim.fastmcp.resources.base.Resource.set_default_name() -> Self

Set default name from URI if not provided.

methodfastmcp_slim.fastmcp.resources.base.Resource.to_mcp_resource(**overrides:Any) -> SDKResource

Convert the resource to an SDKResource.

method

fastmcp_slim.fastmcp.resources.base.ResourceContent.to_mcp_resource_contents(uri:AnyUrl | str) -> mcp_types.TextResourceContents | mcp_types.BlobResourceContents

Convert to MCP resource contents type.

classfastmcp_slim.fastmcp.resources.base.ResourceResult

Canonical result type for resource reads.

methodfastmcp_slim.fastmcp.resources.base.ResourceResult.to_mcp_result(uri:AnyUrl | str) -> mcp_types.ReadResourceResult

Convert to MCP ReadResourceResult.

classfastmcp_slim.fastmcp.resources.function_resource.DecoratedResource

Protocol for functions decorated with @resource.

classfastmcp_slim.fastmcp.resources.template.FunctionResourceTemplate

A template for dynamically creating resources.

method

fastmcp_slim.fastmcp.resources.template.FunctionResourceTemplate.read(arguments:dict[str, Any]) -> str | bytes | ResourceResult

Read the resource content.

classfastmcp_slim.fastmcp.resources.template.ResourceTemplate

A template for dynamically creating resources.

methodfastmcp_slim.fastmcp.resources.template.ResourceTemplate.convert_result(raw_value:Any) -> ResourceResult

Convert a raw result to ResourceResult.

methodfastmcp_slim.fastmcp.resources.template.ResourceTemplate.key() -> str

The globally unique lookup key for this template.

methodfastmcp_slim.fastmcp.resources.template.ResourceTemplate.matches(uri:str) -> dict[str, Any] | None

Check if URI matches template and extract parameters.

methodfastmcp_slim.fastmcp.resources.template.ResourceTemplate.read(arguments:dict[str, Any]) -> str | bytes | ResourceResult

Read the resource content.

methodfastmcp_slim.fastmcp.resources.template.ResourceTemplate.set_default_mime_type(mime_type:str | None) -> str

Set default MIME type if not provided.

classfastmcp_slim.fastmcp.resources.types.BinaryResource

A resource that reads from bytes.

methodfastmcp_slim.fastmcp.resources.types.BinaryResource.read() -> ResourceResult

Read the binary content.

classfastmcp_slim.fastmcp.resources.types.DirectoryResource

A resource that lists files in a directory.

methodfastmcp_slim.fastmcp.resources.types.DirectoryResource.list_files() -> list[Path]

List files in the directory.

methodfastmcp_slim.fastmcp.resources.types.DirectoryResource.read() -> ResourceResult

Read the directory listing.

methodfastmcp_slim.fastmcp.resources.types.DirectoryResource.validate_absolute_path(path:Path) -> Path

Ensure path is absolute.

classfastmcp_slim.fastmcp.resources.types.FileResource

A resource that reads from a file.

methodfastmcp_slim.fastmcp.resources.types.FileResource.read() -> ResourceResult

Read the file content.

methodfastmcp_slim.fastmcp.resources.types.FileResource.validate_absolute_path(path:Path) -> Path

Ensure path is absolute.

classfastmcp_slim.fastmcp.resources.types.HttpResource

A resource that reads from an HTTP endpoint.

methodfastmcp_slim.fastmcp.resources.types.HttpResource.read() -> ResourceResult

Read the HTTP content.

classfastmcp_slim.fastmcp.resources.types.TextResource

A resource that reads from a string.

methodfastmcp_slim.fastmcp.resources.types.TextResource.read() -> ResourceResult

Read the text content.

classfastmcp_slim.fastmcp.server.auth.auth.AccessToken

AccessToken that includes all JWT claims.

classfastmcp_slim.fastmcp.server.auth.auth.AuthProvider

Base class for all FastMCP authentication providers.

methodfastmcp_slim.fastmcp.server.auth.auth.AuthProvider.get_routes(mcp_path:str | None=None) -> list[Route]

Get all routes for this authentication provider.

methodfastmcp_slim.fastmcp.server.auth.auth.AuthProvider.set_mcp_path(mcp_path:str | None) -> None

Set the MCP endpoint path and compute resource URL.

methodfastmcp_slim.fastmcp.server.auth.auth.AuthProvider.verify_token(token:str) -> AccessToken | None

Verify a bearer token and return access info if valid.

classfastmcp_slim.fastmcp.server.auth.auth.OAuthProvider

OAuth Authorization Server provider.

methodfastmcp_slim.fastmcp.server.auth.auth.OAuthProvider.verify_token(token:str) -> AccessToken | None

Verify a bearer token and return access info if valid.

classfastmcp_slim.fastmcp.server.auth.auth.TokenVerifier

Base class for token verifiers (Resource Servers).

methodfastmcp_slim.fastmcp.server.auth.auth.TokenVerifier.verify_token(token:str) -> AccessToken | None

Verify a bearer token and return access info if valid.

classfastmcp_slim.fastmcp.server.auth.cimd.CIMDClientManager

Manages all CIMD client operations for OAuth proxy.

methodfastmcp_slim.fastmcp.server.auth.cimd.CIMDClientManager.is_cimd_client_id(client_id:str) -> bool

Check if client_id is a CIMD URL.

classfastmcp_slim.fastmcp.server.auth.cimd.CIMDFetchError

Raised when CIMD document fetching fails.

classfastmcp_slim.fastmcp.server.auth.cimd.CIMDFetcher

Fetch and validate CIMD documents with SSRF protection.

methodfastmcp_slim.fastmcp.server.auth.cimd.CIMDFetcher.fetch(client_id_url:str) -> CIMDDocument

Fetch and validate a CIMD document with SSRF protection.

methodfastmcp_slim.fastmcp.server.auth.cimd.CIMDFetcher.is_cimd_client_id(client_id:str) -> bool

Check if a client_id looks like a CIMD URL.

classfastmcp_slim.fastmcp.server.auth.cimd.CIMDValidationError

Raised when CIMD document validation fails.

classfastmcp_slim.fastmcp.server.auth.identity_assertion.IdentityAssertionError

Raised when an ID-JAG fails validation.

funcfastmcp_slim.fastmcp.server.auth.identity_assertion.server_url_has_query(url:str) -> bool

Check if a URL has query parameters.

classfastmcp_slim.fastmcp.server.auth.oauth_proxy.models.JTIMapping

Maps FastMCP token JTI to upstream token ID.

classfastmcp_slim.fastmcp.server.auth.oauth_proxy.models.OAuthTransaction

OAuth transaction state for consent flow.

classfastmcp_slim.fastmcp.server.auth.oidc_proxy.OIDCConfiguration

OIDC Configuration.

classfastmcp_slim.fastmcp.server.auth.providers.auth0.Auth0JWTVerifier

JWT verifier for Auth0 MCP access tokens.

classfastmcp_slim.fastmcp.server.auth.providers.auth0.Auth0Provider

An Auth0 provider implementation for FastMCP.

classfastmcp_slim.fastmcp.server.auth.providers.aws.AWSCognitoProvider

Complete AWS Cognito OAuth provider for FastMCP.

classfastmcp_slim.fastmcp.server.auth.providers.aws.AWSCognitoTokenVerifier

Token verifier for Cognito access tokens.

methodfastmcp_slim.fastmcp.server.auth.providers.azure.AzureProvider.close_obo_credentials() -> None

Close all cached OBO credentials.

classfastmcp_slim.fastmcp.server.auth.providers.clerk.ClerkProvider

Complete Clerk OAuth provider for FastMCP.

classfastmcp_slim.fastmcp.server.auth.providers.clerk.ClerkTokenVerifier

Token verifier for Clerk OAuth tokens.

classfastmcp_slim.fastmcp.server.auth.providers.debug.DebugTokenVerifier

Token verifier with custom validation logic.

methodfastmcp_slim.fastmcp.server.auth.providers.debug.DebugTokenVerifier.verify_token(token:str) -> AccessToken | None

Verify token using custom validation logic.

classfastmcp_slim.fastmcp.server.auth.providers.discord.DiscordProvider

Complete Discord OAuth provider for FastMCP.

classfastmcp_slim.fastmcp.server.auth.providers.discord.DiscordTokenVerifier

Token verifier for Discord OAuth tokens.

classfastmcp_slim.fastmcp.server.auth.providers.github.GitHubProvider

Complete GitHub OAuth provider for FastMCP.

classfastmcp_slim.fastmcp.server.auth.providers.github.GitHubTokenVerifier

Token verifier for GitHub OAuth tokens.

methodfastmcp_slim.fastmcp.server.auth.providers.github.GitHubTokenVerifier.verify_token(token:str) -> AccessToken | None

Verify GitHub OAuth token by calling GitHub API.

classfastmcp_slim.fastmcp.server.auth.providers.google.GoogleProvider

Complete Google OAuth provider for FastMCP.

classfastmcp_slim.fastmcp.server.auth.providers.google.GoogleTokenVerifier

Token verifier for Google OAuth tokens.

classfastmcp_slim.fastmcp.server.auth.providers.jwt.JWKData

JSON Web Key data structure.

classfastmcp_slim.fastmcp.server.auth.providers.jwt.JWKSData

JSON Web Key Set data structure.

classfastmcp_slim.fastmcp.server.auth.providers.jwt.RSAKeyPair

RSA key pair for JWT testing.

methodfastmcp_slim.fastmcp.server.auth.providers.jwt.RSAKeyPair.generate() -> RSAKeyPair

Generate an RSA key pair for testing.

classfastmcp_slim.fastmcp.server.auth.providers.workos.WorkOSProvider

Complete WorkOS OAuth provider for FastMCP.

classfastmcp_slim.fastmcp.server.auth.providers.workos.WorkOSTokenVerifier

Token verifier for WorkOS OAuth tokens.

funcfastmcp_slim.fastmcp.server.auth.redirect_validation.is_loopback_host(host:str | None) -> bool

Check if a host is a loopback address.

classfastmcp_slim.fastmcp.server.auth.ssrf.SSRFError

Raised when an SSRF protection check fails.

classfastmcp_slim.fastmcp.server.auth.ssrf.SSRFFetchError

Raised when SSRF-safe fetch fails.

classfastmcp_slim.fastmcp.server.auth.ssrf.SSRFFetchResponse

Response payload from an SSRF-safe fetch.

funcfastmcp_slim.fastmcp.server.auth.ssrf.format_ip_for_url(ip_str:str) -> str

Format IP address for use in URL (bracket IPv6 addresses).

funcfastmcp_slim.fastmcp.server.auth.ssrf.resolve_hostname(hostname:str, port:int=443) -> list[str]

Resolve hostname to IP addresses using DNS.

funcfastmcp_slim.fastmcp.server.auth.ssrf.validate_url(url:str, require_path:bool=False) -> ValidatedURL

Validate URL for SSRF and resolve to IPs.

classfastmcp_slim.fastmcp.server.context.Context

Context object providing access to MCP capabilities.

methodfastmcp_slim.fastmcp.server.context.Context.client_id() -> str | None

Get the client ID if available.

method

fastmcp_slim.fastmcp.server.context.Context.debug(message:str, logger_name:str | None=None, extra:Mapping[str, Any] | None=None) -> None

Send a `DEBUG`-level message to the connected MCP Client.

methodfastmcp_slim.fastmcp.server.context.Context.delete_state(key:str) -> None

Delete a value from the state store.

method

fastmcp_slim.fastmcp.server.context.Context.error(message:str, logger_name:str | None=None, extra:Mapping[str, Any] | None=None) -> None

Send a `ERROR`-level message to the connected MCP Client.

methodfastmcp_slim.fastmcp.server.context.Context.fastmcp() -> FastMCP

Get the FastMCP instance.

method

fastmcp_slim.fastmcp.server.context.Context.get_prompt(name:str, arguments:dict[str, Any] | None=None) -> GetPromptResult

Get a prompt by name with optional arguments.

methodfastmcp_slim.fastmcp.server.context.Context.get_state(key:str) -> Any

Get a value from the state store.

method

fastmcp_slim.fastmcp.server.context.Context.info(message:str, logger_name:str | None=None, extra:Mapping[str, Any] | None=None) -> None

Send a `INFO`-level message to the connected MCP Client.

methodfastmcp_slim.fastmcp.server.context.Context.lifespan_context() -> dict[str, Any]

Access the server's lifespan context.

methodfastmcp_slim.fastmcp.server.context.Context.list_prompts() -> list[SDKPrompt]

List all available prompts from the server.

methodfastmcp_slim.fastmcp.server.context.Context.list_resources() -> list[SDKResource]

List all available resources from the server.

method

fastmcp_slim.fastmcp.server.context.Context.log(message:str, level:LoggingLevel | None=None, logger_name:str | None=None, extra:Mapping[str, Any] | None=None) -> None

Send a log message to the client.

methodfastmcp_slim.fastmcp.server.context.Context.read_resource(uri:str | AnyUrl) -> ResourceResult

Read a resource by URI.

method

fastmcp_slim.fastmcp.server.context.Context.report_progress(progress:float, total:float | None=None, message:str | None=None) -> None

Report progress for the current operation.

methodfastmcp_slim.fastmcp.server.context.Context.request_context() -> FastMCPRequestContext | None

Access to the underlying request context.

methodfastmcp_slim.fastmcp.server.context.Context.request_id() -> str

Get the unique ID for this request.

methodfastmcp_slim.fastmcp.server.context.Context.reset_visibility() -> None

Clear all session visibility rules.

methodfastmcp_slim.fastmcp.server.context.Context.send_notification(notification:mcp_types.ServerNotification) -> None

Send a notification to the client immediately.

methodfastmcp_slim.fastmcp.server.context.Context.session_id() -> str

Get the MCP session ID for ALL transports.

methodfastmcp_slim.fastmcp.server.context.Context.set_state(key:str, value:Any, *serializable:bool=True) -> None

Set a value in the state store.

methodfastmcp_slim.fastmcp.server.context.Context.transport() -> TransportType | None

Get the current transport type.

method

fastmcp_slim.fastmcp.server.context.Context.warning(message:str, logger_name:str | None=None, extra:Mapping[str, Any] | None=None) -> None

Send a `WARNING`-level message to the connected MCP Client.

classfastmcp_slim.fastmcp.server.context.LogData

Data object for passing log arguments to client-side handlers.

funcfastmcp_slim.fastmcp.server.context.reset_transport(token:Token[TransportType | None]) -> None

Reset transport to previous value.

funcfastmcp_slim.fastmcp.server.context.set_transport(transport:TransportType) -> Token[TransportType | None]

Set the current transport type.

funcfastmcp_slim.fastmcp.server.dependencies.CurrentContext() -> Context

Get the current FastMCP Context instance.

funcfastmcp_slim.fastmcp.server.dependencies.CurrentFastMCP() -> FastMCP

Get the current FastMCP server instance.

funcfastmcp_slim.fastmcp.server.dependencies.CurrentHeaders() -> dict[str, str]

Get the current HTTP request headers.

funcfastmcp_slim.fastmcp.server.dependencies.CurrentRequest() -> Request

Get the current HTTP request.

methodfastmcp_slim.fastmcp.server.dependencies.Progress.current() -> int | None

Current progress value.

methodfastmcp_slim.fastmcp.server.dependencies.Progress.increment(amount:int=1) -> None

Atomically increment the current progress value.

methodfastmcp_slim.fastmcp.server.dependencies.Progress.message() -> str | None

Current progress message.

methodfastmcp_slim.fastmcp.server.dependencies.Progress.set_message(message:str | None) -> None

Update the progress status message.

methodfastmcp_slim.fastmcp.server.dependencies.Progress.set_total(total:int) -> None

Set the total/target value for progress tracking.

methodfastmcp_slim.fastmcp.server.dependencies.Progress.total() -> int

Total/target progress value.

classfastmcp_slim.fastmcp.server.dependencies.ProgressLike

Protocol for progress tracking interface.

methodfastmcp_slim.fastmcp.server.dependencies.ProgressLike.current() -> int | None

Current progress value.

methodfastmcp_slim.fastmcp.server.dependencies.ProgressLike.increment(amount:int=1) -> None

Atomically increment the current progress value.

methodfastmcp_slim.fastmcp.server.dependencies.ProgressLike.message() -> str | None

Current progress message.

methodfastmcp_slim.fastmcp.server.dependencies.ProgressLike.set_message(message:str | None) -> None

Update the progress status message.

methodfastmcp_slim.fastmcp.server.dependencies.ProgressLike.set_total(total:int) -> None

Set the total/target value for progress tracking.

methodfastmcp_slim.fastmcp.server.dependencies.ProgressLike.total() -> int

Total/target progress value.

funcfastmcp_slim.fastmcp.server.dependencies.TokenClaim(name:str) -> str

Get a specific claim from the access token.

funcfastmcp_slim.fastmcp.server.dependencies.get_context() -> Context

Get the current FastMCP Context instance directly.

funcfastmcp_slim.fastmcp.server.dependencies.get_http_request() -> Request

Get the current HTTP request.

funcfastmcp_slim.fastmcp.server.dependencies.get_server() -> FastMCP

Get the current FastMCP server instance directly.

funcfastmcp_slim.fastmcp.server.dependencies.get_session(session_id:str) -> Session

Resolve and validate a `Session` for an explicit `session_id`.

classfastmcp_slim.fastmcp.server.elicitation.AcceptedElicitation

Result when user accepts the elicitation.

classfastmcp_slim.fastmcp.server.elicitation.ElicitConfig

Configuration for an elicitation request.

funcfastmcp_slim.fastmcp.server.elicitation.get_elicitation_schema(response_type:type[T]) -> dict[str, Any]

Get the schema for an elicitation response.

func

fastmcp_slim.fastmcp.server.elicitation.handle_elicit_accept(config:ElicitConfig, content:Any) -> AcceptedElicitation[Any]

Handle an accepted elicitation response.

classfastmcp_slim.fastmcp.server.event_store.EventEntry

Stored event entry.

classfastmcp_slim.fastmcp.server.event_store.EventStore

EventStore implementation backed by AsyncKeyValue.

method

fastmcp_slim.fastmcp.server.event_store.EventStore.store_event(stream_id:StreamId, message:JSONRPCMessage | None) -> EventId

Store an event and return its ID.

classfastmcp_slim.fastmcp.server.event_store.StreamEventList

List of event IDs for a stream.

classfastmcp_slim.fastmcp.server.extensions.MethodBinding

A new request method an extension serves, e.g.

classfastmcp_slim.fastmcp.server.lifespan.ComposedLifespan

Two lifespans composed together.

classfastmcp_slim.fastmcp.server.lifespan.Lifespan

Composable lifespan wrapper.

funcfastmcp_slim.fastmcp.server.lifespan.lifespan(fn:LifespanFn) -> Lifespan

Decorator to create a composable lifespan.

classfastmcp_slim.fastmcp.server.middleware.caching.CacheableMessage

A wrapper for Message that can be cached.

classfastmcp_slim.fastmcp.server.middleware.caching.CacheablePromptResult

A wrapper for PromptResult that can be cached.

classfastmcp_slim.fastmcp.server.middleware.caching.CacheableResourceResult

A wrapper for ResourceResult that can be cached.

classfastmcp_slim.fastmcp.server.middleware.caching.CallToolSettings

Configuration options for Tool-related caching.

classfastmcp_slim.fastmcp.server.middleware.caching.GetPromptSettings

Configuration options for Prompt-related caching.

classfastmcp_slim.fastmcp.server.middleware.caching.ListPromptsSettings

Configuration options for Prompt-related caching.

classfastmcp_slim.fastmcp.server.middleware.caching.ListToolsSettings

Configuration options for Tool-related caching.

classfastmcp_slim.fastmcp.server.middleware.caching.SharedMethodSettings

Shared config for a cache method.

classfastmcp_slim.fastmcp.server.middleware.logging.BaseLoggingMiddleware

Base class for logging middleware.

method

fastmcp_slim.fastmcp.server.middleware.logging.BaseLoggingMiddleware.on_message(context:MiddlewareContext[Any], call_next:CallNext[Any, Any]) -> Any

Log messages for configured methods.

classfastmcp_slim.fastmcp.server.middleware.middleware.Middleware

Base class for FastMCP middleware with dispatching hooks.

classfastmcp_slim.fastmcp.server.middleware.middleware.MiddlewareContext

Unified context for all middleware operations.

classfastmcp_slim.fastmcp.server.middleware.rate_limiting.RateLimitError

Error raised when rate limit is exceeded.

classfastmcp_slim.fastmcp.server.middleware.rate_limiting.SlidingWindowRateLimiter

Sliding window rate limiter implementation.

methodfastmcp_slim.fastmcp.server.middleware.rate_limiting.SlidingWindowRateLimiter.is_allowed() -> bool

Check if a request is allowed.

classfastmcp_slim.fastmcp.server.middleware.rate_limiting.TokenBucketRateLimiter

Token bucket implementation for rate limiting.

methodfastmcp_slim.fastmcp.server.middleware.rate_limiting.TokenBucketRateLimiter.consume(tokens:int=1) -> bool

Try to consume tokens from the bucket.

method

fastmcp_slim.fastmcp.server.middleware.timing.TimingMiddleware.on_request(context:MiddlewareContext, call_next:CallNext) -> Any

Time request execution and log the results.

classfastmcp_slim.fastmcp.server.mixins.lifespan.LifespanMixin

Mixin providing lifespan infrastructure for FastMCP.

method

fastmcp_slim.fastmcp.server.mixins.transport.TransportMixin.run(transport:Transport | None=None, show_banner:bool | None=None, **transport_kwargs:Any) -> None

Run the FastMCP server.

method

fastmcp_slim.fastmcp.server.mixins.transport.TransportMixin.run_async(transport:Transport | None=None, show_banner:bool | None=None, **transport_kwargs:Any) -> None

Run the FastMCP server asynchronously.

method

fastmcp_slim.fastmcp.server.mixins.transport.TransportMixin.run_stdio_async(show_banner:bool=True, log_level:str | None=None, stateless:bool=False) -> None

Run the server using stdio transport.

funcfastmcp_slim.fastmcp.server.providers.addressing.hash_tool(app_name:str, tool_name:str) -> str

Deterministic hex hash for a tool in an app.

funcfastmcp_slim.fastmcp.server.providers.addressing.hashed_resource_uri(app_name:str, tool_name:str) -> str

Per-tool Prefab renderer resource URI.

funcfastmcp_slim.fastmcp.server.providers.addressing.parse_hashed_resource_uri(uri:str) -> str | None

Extract the hash from a Prefab renderer URI, or None.

classfastmcp_slim.fastmcp.server.providers.base.Provider

Base class for dynamic component providers.

methodfastmcp_slim.fastmcp.server.providers.base.Provider.add_transform(transform:Transform) -> None

Add a transform to this provider.

methodfastmcp_slim.fastmcp.server.providers.base.Provider.list_prompts() -> Sequence[Prompt]

List prompts with all transforms applied.

methodfastmcp_slim.fastmcp.server.providers.base.Provider.list_resources() -> Sequence[Resource]

List resources with all transforms applied.

methodfastmcp_slim.fastmcp.server.providers.base.Provider.list_tools() -> Sequence[Tool]

List tools with all transforms applied.

classfastmcp_slim.fastmcp.server.providers.fastmcp_provider.FastMCPProvider

Provider that wraps a FastMCP server.

methodfastmcp_slim.fastmcp.server.providers.fastmcp_provider.FastMCPProvider.lifespan() -> AsyncIterator[None]

Start the mounted server's lifespan.

classfastmcp_slim.fastmcp.server.providers.filesystem_discovery.DiscoveryResult

Result of filesystem discovery.

funcfastmcp_slim.fastmcp.server.providers.filesystem_discovery.discover_files(root:Path) -> list[Path]

Recursively discover all Python files under a directory.

func

fastmcp_slim.fastmcp.server.providers.filesystem_discovery.extract_components(module:ModuleType) -> list[FastMCPComponent]

Extract all MCP components from a module.

func

fastmcp_slim.fastmcp.server.providers.filesystem_discovery.import_module_from_file(file_path:Path, provider_root:Path | None=None) -> ModuleType

Import a Python file as a module.

classfastmcp_slim.fastmcp.server.providers.local_provider.local_provider.LocalProvider

Provider for locally-defined components.

method

fastmcp_slim.fastmcp.server.providers.local_provider.local_provider.LocalProvider.remove_tool(name:str, version:str | None=None) -> None

Remove tool(s) from this provider's storage.

classfastmcp_slim.fastmcp.server.providers.openapi.components.OpenAPIResource

Resource implementation for OpenAPI endpoints.

classfastmcp_slim.fastmcp.server.providers.openapi.components.OpenAPITool

Tool implementation for OpenAPI endpoints.

methodfastmcp_slim.fastmcp.server.providers.openapi.components.OpenAPITool.run(arguments:dict[str, Any]) -> ToolResult

Execute the HTTP request using RequestDirector.

classfastmcp_slim.fastmcp.server.providers.openapi.routing.MCPType

Type of FastMCP component to create from a route.

methodfastmcp_slim.fastmcp.server.providers.proxy.ProxyResource.model_copy(**kwargs:Any) -> ProxyResource

Override to preserve _backend_uri when uri changes.

funcfastmcp_slim.fastmcp.server.providers.proxy.as_proxy_backend(c:Client) -> Client

Apply proxy connection settings to a copy we own.

classfastmcp_slim.fastmcp.server.providers.skills._common.SkillFileInfo

Information about a file within a skill.

classfastmcp_slim.fastmcp.server.providers.skills._common.SkillInfo

Parsed information about a skill.

funcfastmcp_slim.fastmcp.server.providers.skills._common.compute_file_hash(path:Path) -> str

Compute SHA256 hash of a file.

funcfastmcp_slim.fastmcp.server.providers.skills._common.parse_frontmatter(content:str) -> tuple[dict[str, Any], str]

Parse YAML frontmatter from markdown content.

funcfastmcp_slim.fastmcp.server.providers.skills._common.scan_skill_files(skill_dir:Path) -> list[SkillFileInfo]

Scan a skill directory for all files.

method

fastmcp_slim.fastmcp.server.providers.skills.skill_provider.SkillFileTemplate.read(arguments:dict[str, Any]) -> str | bytes | ResourceResult

Read a file from the skill directory.

classfastmcp_slim.fastmcp.server.providers.skills.vendor_providers.CursorSkillsProvider

Cursor skills from ~/.cursor/skills/.

classfastmcp_slim.fastmcp.server.providers.skills.vendor_providers.GeminiSkillsProvider

Gemini skills from ~/.gemini/skills/.

classfastmcp_slim.fastmcp.server.providers.skills.vendor_providers.GooseSkillsProvider

Goose skills from ~/.config/agents/skills/.

classfastmcp_slim.fastmcp.server.providers.skills.vendor_providers.VSCodeSkillsProvider

VS Code skills from ~/.copilot/skills/.

classfastmcp_slim.fastmcp.server.server.StateValue

Wrapper for stored context state values.

funcfastmcp_slim.fastmcp.server.server.default_lifespan(server:FastMCP[LifespanResultT]) -> AsyncIterator[Any]

Default lifespan context manager that does nothing.

methodfastmcp_slim.fastmcp.server.sessions.Session.delete(key:str) -> None

Remove `key` from this session, if present (preserves the marker).

methodfastmcp_slim.fastmcp.server.sessions.Session.get(key:str, default:Any=None) -> Any

Return the value for `key`, or `default` when it is not set.

methodfastmcp_slim.fastmcp.server.sessions.Session.set(key:str, value:Any) -> None

Store `value` under `key` in this session (read-modify-write).

classfastmcp_slim.fastmcp.server.sessions.SessionProvider

Provider contributing the session lifecycle tools.

classfastmcp_slim.fastmcp.server.sessions.UserSession

Annotation marker for the injected per-user session.

funcfastmcp_slim.fastmcp.server.sessions.create_session() -> str

Create a new session and return its identifier.

funcfastmcp_slim.fastmcp.server.sessions.end_session(session_id:SessionId) -> str

End a session and delete all of its state.

funcfastmcp_slim.fastmcp.server.sessions.session_storage_key(principal:str | None, session_id:str) -> str

The single storage key holding a session's state dict.

funcfastmcp_slim.fastmcp.server.telemetry.record_span_exception(span:Span, e:Exception) -> None

Record an exception and error status on a span.

classfastmcp_slim.fastmcp.server.transforms.GetPromptNext

Protocol for get_prompt call_next functions.

classfastmcp_slim.fastmcp.server.transforms.GetResourceNext

Protocol for get_resource call_next functions.

classfastmcp_slim.fastmcp.server.transforms.GetToolNext

Protocol for get_tool call_next functions.

classfastmcp_slim.fastmcp.server.transforms.Transform

Base class for component transformations.

method

fastmcp_slim.fastmcp.server.transforms.Transform.get_prompt(name:str, call_next:GetPromptNext, *version:VersionSpec | None=None) -> Prompt | None

Get a prompt by name.

method

fastmcp_slim.fastmcp.server.transforms.Transform.get_resource(uri:str, call_next:GetResourceNext, *version:VersionSpec | None=None) -> Resource | None

Get a resource by URI.

method

fastmcp_slim.fastmcp.server.transforms.Transform.get_resource_template(uri:str, call_next:GetResourceTemplateNext, *version:VersionSpec | None=None) -> ResourceTemplate | None

Get a resource template by URI.

method

fastmcp_slim.fastmcp.server.transforms.Transform.get_tool(name:str, call_next:GetToolNext, *version:VersionSpec | None=None) -> Tool | None

Get a tool by name.

methodfastmcp_slim.fastmcp.server.transforms.Transform.list_prompts(prompts:Sequence[Prompt]) -> Sequence[Prompt]

List prompts with transformation applied.

methodfastmcp_slim.fastmcp.server.transforms.Transform.list_resources(resources:Sequence[Resource]) -> Sequence[Resource]

List resources with transformation applied.

methodfastmcp_slim.fastmcp.server.transforms.Transform.list_tools(tools:Sequence[Tool]) -> Sequence[Tool]

List tools with transformation applied.

classfastmcp_slim.fastmcp.server.transforms.namespace.Namespace

Prefixes component names with a namespace.

method

fastmcp_slim.fastmcp.server.transforms.namespace.Namespace.get_prompt(name:str, call_next:GetPromptNext, *version:VersionSpec | None=None) -> Prompt | None

Get prompt by namespaced name.

method

fastmcp_slim.fastmcp.server.transforms.namespace.Namespace.get_resource(uri:str, call_next:GetResourceNext, *version:VersionSpec | None=None) -> Resource | None

Get resource by namespaced URI.

method

fastmcp_slim.fastmcp.server.transforms.namespace.Namespace.get_tool(name:str, call_next:GetToolNext, *version:VersionSpec | None=None) -> Tool | None

Get tool by namespaced name.

methodfastmcp_slim.fastmcp.server.transforms.namespace.Namespace.list_prompts(prompts:Sequence[Prompt]) -> Sequence[Prompt]

Prefix prompt names with namespace.

method

fastmcp_slim.fastmcp.server.transforms.namespace.Namespace.list_resources(resources:Sequence[Resource]) -> Sequence[Resource]

Add namespace path segment to resource URIs.

methodfastmcp_slim.fastmcp.server.transforms.namespace.Namespace.list_tools(tools:Sequence[Tool]) -> Sequence[Tool]

Prefix tool names with namespace.

funcfastmcp_slim.fastmcp.server.transforms.prompts_as_tools.PromptsAsTools.list_prompts() -> str

List all available prompts.

func

fastmcp_slim.fastmcp.server.transforms.resources_as_tools.ResourcesAsTools.read_resource(uri:Annotated[str, 'The URI of the resource to read']) -> str

Read a resource by its URI.

classfastmcp_slim.fastmcp.server.transforms.search.base.BaseSearchTransform

Replace the tool listing with a search interface.

classfastmcp_slim.fastmcp.server.transforms.search.regex.RegexSearchTransform

Search transform using regex pattern matching.

classfastmcp_slim.fastmcp.server.transforms.version_filter.VersionFilter

Filters components by version range.

classfastmcp_slim.fastmcp.server.transforms.visibility.Visibility

Sets visibility state on matching components.

method

fastmcp_slim.fastmcp.server.transforms.visibility.Visibility.get_prompt(name:str, call_next:GetPromptNext, *version:VersionSpec | None=None) -> Prompt | None

Mark prompt if found.

method

fastmcp_slim.fastmcp.server.transforms.visibility.Visibility.get_resource(uri:str, call_next:GetResourceNext, *version:VersionSpec | None=None) -> Resource | None

Mark resource if found.

method

fastmcp_slim.fastmcp.server.transforms.visibility.Visibility.get_resource_template(uri:str, call_next:GetResourceTemplateNext, *version:VersionSpec | None=None) -> ResourceTemplate | None

Mark resource template if found.

method

fastmcp_slim.fastmcp.server.transforms.visibility.Visibility.get_tool(name:str, call_next:GetToolNext, *version:VersionSpec | None=None) -> Tool | None

Mark tool if found.

methodfastmcp_slim.fastmcp.server.transforms.visibility.Visibility.list_prompts(prompts:Sequence[Prompt]) -> Sequence[Prompt]

Mark prompts by visibility state.

method

fastmcp_slim.fastmcp.server.transforms.visibility.Visibility.list_resources(resources:Sequence[Resource]) -> Sequence[Resource]

Mark resources by visibility state.

methodfastmcp_slim.fastmcp.server.transforms.visibility.Visibility.list_tools(tools:Sequence[Tool]) -> Sequence[Tool]

Mark tools by visibility state.

func

fastmcp_slim.fastmcp.server.transforms.visibility.create_visibility_transforms(rules:list[dict[str, Any]]) -> list[Visibility]

Convert rule dicts to Visibility transforms.

funcfastmcp_slim.fastmcp.server.transforms.visibility.get_visibility_rules(context:Context) -> list[dict[str, Any]]

Load visibility rule dicts from session state.

funcfastmcp_slim.fastmcp.server.transforms.visibility.is_enabled(component:FastMCPComponent) -> bool

Check if component is enabled.

funcfastmcp_slim.fastmcp.server.transforms.visibility.reset_visibility(context:Context) -> None

Clear all session visibility rules.

classfastmcp_slim.fastmcp.settings.Settings

FastMCP settings.

methodfastmcp_slim.fastmcp.settings.Settings.get_setting(attr:str) -> Any

Get a setting.

methodfastmcp_slim.fastmcp.settings.Settings.set_setting(attr:str, value:Any) -> None

Set a setting.

funcfastmcp_slim.fastmcp.telemetry.extract_trace_context(meta:dict[str, Any] | None) -> Context

Extract trace context from an MCP request meta dict.

funcfastmcp_slim.fastmcp.telemetry.get_tracer(version:str | None=None) -> Tracer

Get the FastMCP tracer for creating spans.

funcfastmcp_slim.fastmcp.telemetry.native_spans_enabled() -> bool

Whether FastMCP should create its own spans right now.

funcfastmcp_slim.fastmcp.telemetry.record_span_error(span:Span, exception:BaseException) -> None

Record an exception on a span and set error status.

funcfastmcp_slim.fastmcp.utilities.auth.decode_jwt_header(token:str) -> dict[str, Any]

Decode JWT header without signature verification.

funcfastmcp_slim.fastmcp.utilities.auth.decode_jwt_payload(token:str) -> dict[str, Any]

Decode JWT payload without signature verification.

funcfastmcp_slim.fastmcp.utilities.auth.parse_scopes(value:Any) -> list[str] | None

Parse scopes from environment variables or settings values.

classfastmcp_slim.fastmcp.utilities.authorization.AuthContext

Context passed to auth check callables.

funcfastmcp_slim.fastmcp.utilities.authorization.require_scopes(*scopes:str) -> AuthCheck

Require all of the given OAuth scopes.

funcfastmcp_slim.fastmcp.utilities.components.get_fastmcp_metadata(meta:dict[str, Any] | None) -> FastMCPMeta

Extract FastMCP metadata from a component's meta dict.

funcfastmcp_slim.fastmcp.utilities.http.find_available_port(host:str='127.0.0.1') -> int

Find an available port by letting the OS assign one.

classfastmcp_slim.fastmcp.utilities.inspect.FastMCPInfo

Information extracted from a FastMCP instance.

classfastmcp_slim.fastmcp.utilities.inspect.InspectFormat

Output format for inspect command.

classfastmcp_slim.fastmcp.utilities.inspect.PromptInfo

Information about a prompt.

classfastmcp_slim.fastmcp.utilities.inspect.ResourceInfo

Information about a resource.

classfastmcp_slim.fastmcp.utilities.inspect.TemplateInfo

Information about a resource template.

classfastmcp_slim.fastmcp.utilities.inspect.ToolInfo

Information about a tool.

funcfastmcp_slim.fastmcp.utilities.inspect.format_fastmcp_info(info:FastMCPInfo) -> bytes

Format FastMCPInfo as FastMCP-specific JSON.

funcfastmcp_slim.fastmcp.utilities.inspect.format_mcp_info(mcp:FastMCP[Any] | SDKServer) -> bytes

Format server info as standard MCP protocol JSON.

funcfastmcp_slim.fastmcp.utilities.inspect.inspect_fastmcp_v2(mcp:FastMCP[Any]) -> FastMCPInfo

Extract information from a FastMCP v2.x instance.

funcfastmcp_slim.fastmcp.utilities.logging.get_logger(name:str) -> logging.Logger

Get a logger nested under FastMCP namespace.

classfastmcp_slim.fastmcp.utilities.mcp_server_config.v1.environments.base.Environment

Base class for environment configuration.

method

fastmcp_slim.fastmcp.utilities.mcp_server_config.v1.environments.base.Environment.build_command(command:list[str]) -> list[str]

Build the full command with environment setup.

classfastmcp_slim.fastmcp.utilities.mcp_server_config.v1.environments.uv.UVEnvironment

Configuration for Python environment setup.

method

fastmcp_slim.fastmcp.utilities.mcp_server_config.v1.environments.uv.UVEnvironment.prepare(output_dir:Path | None=None) -> None

Prepare the Python environment using uv.

classfastmcp_slim.fastmcp.utilities.mcp_server_config.v1.mcp_server_config.MCPServerConfig

Configuration for a FastMCP server.

method

fastmcp_slim.fastmcp.utilities.mcp_server_config.v1.mcp_server_config.MCPServerConfig.from_file(file_path:Path) -> MCPServerConfig

Load configuration from a JSON file.

method

fastmcp_slim.fastmcp.utilities.mcp_server_config.v1.mcp_server_config.MCPServerConfig.prepare(skip_source:bool=False, output_dir:Path | None=None) -> None

Prepare environment and source for execution.

method

fastmcp_slim.fastmcp.utilities.mcp_server_config.v1.mcp_server_config.MCPServerConfig.prepare_environment(output_dir:Path | None=None) -> None

Prepare the Python environment.

methodfastmcp_slim.fastmcp.utilities.mcp_server_config.v1.mcp_server_config.MCPServerConfig.prepare_source() -> None

Prepare the source for loading.

methodfastmcp_slim.fastmcp.utilities.mcp_server_config.v1.mcp_server_config.MCPServerConfig.run_server(**kwargs:Any) -> None

Load and run the server with this configuration.

classfastmcp_slim.fastmcp.utilities.mcp_server_config.v1.sources.base.Source

Abstract base class for all source types.

methodfastmcp_slim.fastmcp.utilities.mcp_server_config.v1.sources.base.Source.load_server() -> Any

Load and return the FastMCP server instance.

classfastmcp_slim.fastmcp.utilities.mcp_server_config.v1.sources.filesystem.FileSystemSource

Source for local Python files.

methodfastmcp_slim.fastmcp.utilities.mcp_server_config.v1.sources.filesystem.FileSystemSource.load_server() -> Any

Load server from filesystem.

funcfastmcp_slim.fastmcp.utilities.mime.resolve_ui_mime_type(uri:str, explicit_mime_type:str | None) -> str | None

Return the appropriate MIME type for a resource URI.

classfastmcp_slim.fastmcp.utilities.openapi.models.ResponseInfo

Represents response information in our IR.

funcfastmcp_slim.fastmcp.utilities.openapi.parser.OpenAPIParser.collect(schema_name:str) -> None

Collect a schema by name and recurse into its dependencies.

funcfastmcp_slim.fastmcp.utilities.openapi.parser.OpenAPIParser.find_refs(obj)

Recursively find all $ref references.

classfastmcp_slim.fastmcp.utilities.pagination.CursorState

Internal representation of pagination cursor state.

methodfastmcp_slim.fastmcp.utilities.pagination.CursorState.decode(cursor:str) -> CursorState

Decode cursor from an opaque string.

methodfastmcp_slim.fastmcp.utilities.pagination.CursorState.encode() -> str

Encode cursor state to an opaque string.

func

fastmcp_slim.fastmcp.utilities.pagination.paginate_sequence(items:Sequence[T], cursor:str | None, page_size:int) -> tuple[list[T], str | None]

Paginate a sequence of items.

funcfastmcp_slim.fastmcp.utilities.prefab.is_prefab_app(value:Any) -> bool

Return whether a value is a Prefab app.

funcfastmcp_slim.fastmcp.utilities.prefab.is_prefab_component(value:Any) -> bool

Return whether a value is a Prefab component.

funcfastmcp_slim.fastmcp.utilities.prefab.is_prefab_type(candidate:Any) -> bool

Return whether a type is a Prefab app or component type.

funcfastmcp_slim.fastmcp.utilities.prefab.prefab_app_from_component(component:Any) -> Any

Wrap a Prefab component in a Prefab app.

classfastmcp_slim.fastmcp.utilities.skills.SkillFile

Information about a file within a skill.

classfastmcp_slim.fastmcp.utilities.skills.SkillManifest

Full manifest of a skill including all files.

classfastmcp_slim.fastmcp.utilities.skills.SkillSummary

Summary information about a skill available on a server.

About this data

These signatures were extracted from the public source of PrefectHQ/fastmcp using Python's ast module. Argument names, default values, type annotations and return types are taken verbatim from the code. Implementation bodies are never stored. See how it works for details.

Back to all 805 libraries