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Message View Classes

Message view classes provide zero-copy access to protocol-specific data structures.

HttpMessage

cymongoose.HttpMessage

Lightweight view over a struct mg_http_message.

Source code in src/cymongoose/_mongoose.pyi 
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class HttpMessage:
    """Lightweight view over a struct mg_http_message."""

    @property
    def method(self) -> str:
        """HTTP method (GET, POST, etc.)."""
        ...

    @property
    def uri(self) -> str:
        """Request URI path."""
        ...

    @property
    def query(self) -> str:
        """Query string."""
        ...

    @property
    def proto(self) -> str:
        """HTTP protocol version (HTTP/1.1, etc.)."""
        ...

    @property
    def body_bytes(self) -> bytes:
        """Request/response body as bytes."""
        ...

    @property
    def body_text(self) -> str:
        """Request/response body as UTF-8 text."""
        ...

    def header(self, name: str, default: Optional[str] = None) -> Optional[str]:
        """Return a HTTP header value or default when not present.

        Args:
            name: Header name (case-insensitive)
            default: Default value if header not found

        Returns:
            Header value or default
        """
        ...

    def headers(self) -> List[Tuple[str, str]]:
        """Return all HTTP headers as a list of (name, value) tuples."""
        ...

    def query_var(self, name: str) -> Optional[str]:
        """Extract a query string parameter.

        Args:
            name: Parameter name

        Returns:
            Parameter value or None if not found

        Raises:
            ValueError: If decoded value exceeds 2048-byte buffer limit
        """
        ...

    def status(self) -> Optional[int]:
        """Return HTTP status code from response message.

        Returns:
            Status code (e.g., 200, 404) or None if not available
        """
        ...

    def header_var(self, header_name: str, var_name: str) -> Optional[str]:
        """Parse a variable from a header value.

        Useful for parsing sub-values like charset from Content-Type header.
        Example: header_var("Content-Type", "charset") -> "utf-8"

        Args:
            header_name: Name of the header (e.g., "Content-Type")
            var_name: Name of the variable to extract (e.g., "charset")

        Returns:
            The variable value or None if not found
        """
        ...

    def __bool__(self) -> bool: ...

method property

HTTP method (GET, POST, etc.).

uri property

Request URI path.

query property

Query string.

proto property

HTTP protocol version (HTTP/1.1, etc.).

body_bytes property

Request/response body as bytes.

body_text property

Request/response body as UTF-8 text.

header(name, default=None)

Return a HTTP header value or default when not present.

Parameters:

Name Type Description Default
name str

Header name (case-insensitive)

 required
default Optional[str]

Default value if header not found

 None

Returns:

Type Description
Optional[str]

Header value or default
Source code in src/cymongoose/_mongoose.pyi 
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def header(self, name: str, default: Optional[str] = None) -> Optional[str]:
    """Return a HTTP header value or default when not present.

    Args:
        name: Header name (case-insensitive)
        default: Default value if header not found

    Returns:
        Header value or default
    """
    ...

headers()

Return all HTTP headers as a list of (name, value) tuples.

Source code in src/cymongoose/_mongoose.pyi 
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def headers(self) -> List[Tuple[str, str]]:
    """Return all HTTP headers as a list of (name, value) tuples."""
    ...

query_var(name)

Extract a query string parameter.

Parameters:

Name Type Description Default
name str

Parameter name

 required

Returns:

Type Description
Optional[str]

Parameter value or None if not found

Raises:

Type Description
ValueError

If decoded value exceeds 2048-byte buffer limit
Source code in src/cymongoose/_mongoose.pyi 
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def query_var(self, name: str) -> Optional[str]:
    """Extract a query string parameter.

    Args:
        name: Parameter name

    Returns:
        Parameter value or None if not found

    Raises:
        ValueError: If decoded value exceeds 2048-byte buffer limit
    """
    ...

status()

Return HTTP status code from response message.

Returns:

Type Description
Optional[int]

Status code (e.g., 200, 404) or None if not available
Source code in src/cymongoose/_mongoose.pyi 
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def status(self) -> Optional[int]:
    """Return HTTP status code from response message.

    Returns:
        Status code (e.g., 200, 404) or None if not available
    """
    ...

header_var(header_name, var_name)

Parse a variable from a header value.

Useful for parsing sub-values like charset from Content-Type header. Example: header_var("Content-Type", "charset") -> "utf-8"

Parameters:

Name Type Description Default
header_name str

Name of the header (e.g., "Content-Type")

 required
var_name str

Name of the variable to extract (e.g., "charset")

 required

Returns:

Type Description
Optional[str]

The variable value or None if not found
Source code in src/cymongoose/_mongoose.pyi 
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def header_var(self, header_name: str, var_name: str) -> Optional[str]:
    """Parse a variable from a header value.

    Useful for parsing sub-values like charset from Content-Type header.
    Example: header_var("Content-Type", "charset") -> "utf-8"

    Args:
        header_name: Name of the header (e.g., "Content-Type")
        var_name: Name of the variable to extract (e.g., "charset")

    Returns:
        The variable value or None if not found
    """
    ...

__bool__()

Source code in src/cymongoose/_mongoose.pyi 
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def __bool__(self) -> bool: ...

Overview

HttpMessage provides access to HTTP request/response data without copying. It's a view over the underlying C mg_http_message struct.

Lifetime: Only valid within the event handler for MG_EV_HTTP_MSG or MG_EV_HTTP_HDRS events.

Example

from cymongoose import MG_EV_HTTP_MSG

def handler(conn, ev, data):
    if ev == MG_EV_HTTP_MSG:
        # data is HttpMessage
        print(f"{data.method} {data.uri}")

        # Query parameters
        user_id = data.query_var("id")

        # Headers
        content_type = data.header("Content-Type")
        for name, value in data.headers():
            print(f"{name}: {value}")

        # Body
        body = data.body_bytes  # bytes
        text = data.body_text   # str

        # Status (for responses)
        if data.status():
            print(f"HTTP {data.status()}")

WsMessage

cymongoose.WsMessage

View over an incoming WebSocket frame.

Source code in src/cymongoose/_mongoose.pyi 
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class WsMessage:
    """View over an incoming WebSocket frame."""

    @property
    def data(self) -> bytes:
        """Frame data as bytes."""
        ...

    @property
    def text(self) -> str:
        """Frame data as UTF-8 text."""
        ...

    @property
    def flags(self) -> int:
        """WebSocket frame flags."""
        ...

data property

Frame data as bytes.

text property

Frame data as UTF-8 text.

flags property

WebSocket frame flags.

Overview

WsMessage provides access to WebSocket frame data.

Lifetime: Only valid within MG_EV_WS_MSG event handler.

Example

from cymongoose import (
    MG_EV_WS_MSG,
    WEBSOCKET_OP_TEXT,
    WEBSOCKET_OP_BINARY,
    WEBSOCKET_OP_PING,
    WEBSOCKET_OP_PONG,
)

def handler(conn, ev, data):
    if ev == MG_EV_WS_MSG:
        # data is WsMessage
        if data.flags == WEBSOCKET_OP_TEXT:
            print(f"Text: {data.text}")
        elif data.flags == WEBSOCKET_OP_BINARY:
            print(f"Binary: {len(data.data)} bytes")
        elif data.flags == WEBSOCKET_OP_PING:
            # Respond to ping
            conn.ws_send(b"", WEBSOCKET_OP_PONG)

MqttMessage

cymongoose.MqttMessage

View over an incoming MQTT message.

Source code in src/cymongoose/_mongoose.pyi 
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class MqttMessage:
    """View over an incoming MQTT message."""

    @property
    def topic(self) -> str:
        """MQTT topic."""
        ...

    @property
    def data(self) -> bytes:
        """Message payload as bytes."""
        ...

    @property
    def text(self) -> str:
        """Message payload as UTF-8 text."""
        ...

    @property
    def id(self) -> int:
        """Message ID."""
        ...

    @property
    def cmd(self) -> int:
        """MQTT command type."""
        ...

    @property
    def qos(self) -> int:
        """Quality of Service level."""
        ...

    @property
    def ack(self) -> int:
        """Acknowledgement field."""
        ...

topic property

MQTT topic.

data property

Message payload as bytes.

text property

Message payload as UTF-8 text.

id property

Message ID.

cmd property

MQTT command type.

qos property

Quality of Service level.

ack property

Acknowledgement field.

Overview

MqttMessage provides access to MQTT message data.

Lifetime: Only valid within MG_EV_MQTT_MSG or MG_EV_MQTT_CMD event handlers.

Example

from cymongoose import MG_EV_MQTT_MSG, MG_EV_MQTT_CMD

def handler(conn, ev, data):
    if ev == MG_EV_MQTT_MSG:
        # data is MqttMessage
        print(f"Topic: {data.topic}")
        print(f"Message: {data.text}")
        print(f"QoS: {data.qos}")
        print(f"Message ID: {data.id}")

        # Parse JSON payload
        import json
        payload = json.loads(data.text)

    elif ev == MG_EV_MQTT_CMD:
        # MQTT command (CONNECT, SUBSCRIBE, etc.)
        print(f"Command: {data.cmd}")

TlsOpts

cymongoose.TlsOpts

TLS configuration options for secure connections.

Used to configure TLS/SSL settings for HTTPS, WSS, MQTTS, etc.

Source code in src/cymongoose/_mongoose.pyi 
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class TlsOpts:
    """TLS configuration options for secure connections.

    Used to configure TLS/SSL settings for HTTPS, WSS, MQTTS, etc.
    """

    ca: bytes
    cert: bytes
    key: bytes
    name: bytes
    skip_verification: bool

    def __init__(
        self,
        ca: Union[bytes, str, None] = None,
        cert: Union[bytes, str, None] = None,
        key: Union[bytes, str, None] = None,
        name: Union[bytes, str, None] = None,
        skip_verification: bool = False,
    ) -> None:
        """Initialize TLS options.

        Args:
            ca: CA certificate (PEM format) as bytes or str
            cert: Client certificate (PEM format) as bytes or str
            key: Private key (PEM format) as bytes or str
            name: Server name for SNI (Server Name Indication)
            skip_verification: Skip certificate verification (INSECURE - dev only!)

        Example:
            # Server with custom certificate
            opts = TlsOpts(
                cert=open('server.crt', 'rb').read(),
                key=open('server.key', 'rb').read()
            )

            # Client with custom CA
            opts = TlsOpts(
                ca=open('ca.crt', 'rb').read(),
                name='example.com'
            )

            # Development only - skip verification
            opts = TlsOpts(skip_verification=True)
        """
        ...

ca instance-attribute

cert instance-attribute

key instance-attribute

name instance-attribute

skip_verification instance-attribute

__init__(ca=None, cert=None, key=None, name=None, skip_verification=False)

Initialize TLS options.

Parameters:

Name Type Description Default
ca Union[bytes, str, None]

CA certificate (PEM format) as bytes or str

 None
cert Union[bytes, str, None]

Client certificate (PEM format) as bytes or str

 None
key Union[bytes, str, None]

Private key (PEM format) as bytes or str

 None
name Union[bytes, str, None]

Server name for SNI (Server Name Indication)

 None
skip_verification bool

Skip certificate verification (INSECURE - dev only!)

 False
Example

Server with custom certificate

opts = TlsOpts( cert=open('server.crt', 'rb').read(), key=open('server.key', 'rb').read() )

Client with custom CA

opts = TlsOpts( ca=open('ca.crt', 'rb').read(), name='example.com' )

Development only - skip verification

opts = TlsOpts(skip_verification=True)

Source code in src/cymongoose/_mongoose.pyi 
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def __init__(
    self,
    ca: Union[bytes, str, None] = None,
    cert: Union[bytes, str, None] = None,
    key: Union[bytes, str, None] = None,
    name: Union[bytes, str, None] = None,
    skip_verification: bool = False,
) -> None:
    """Initialize TLS options.

    Args:
        ca: CA certificate (PEM format) as bytes or str
        cert: Client certificate (PEM format) as bytes or str
        key: Private key (PEM format) as bytes or str
        name: Server name for SNI (Server Name Indication)
        skip_verification: Skip certificate verification (INSECURE - dev only!)

    Example:
        # Server with custom certificate
        opts = TlsOpts(
            cert=open('server.crt', 'rb').read(),
            key=open('server.key', 'rb').read()
        )

        # Client with custom CA
        opts = TlsOpts(
            ca=open('ca.crt', 'rb').read(),
            name='example.com'
        )

        # Development only - skip verification
        opts = TlsOpts(skip_verification=True)
    """
    ...

Overview

TlsOpts configures TLS/SSL settings for secure connections.

Example

from cymongoose import TlsOpts, MG_EV_ACCEPT

# Server with certificate
cert = open("server.crt", "rb").read()
key = open("server.key", "rb").read()

server_opts = TlsOpts(cert=cert, key=key)

# Client with custom CA
ca = open("custom-ca.crt", "rb").read()
client_opts = TlsOpts(ca=ca, name="example.com")

# Development mode (skip verification - INSECURE!)
dev_opts = TlsOpts(skip_verification=True)

def handler(conn, ev, data):
    if ev == MG_EV_ACCEPT:
        # Initialize TLS on new connection
        conn.tls_init(server_opts)

Timer

cymongoose.Timer

Wrapper for Mongoose timer.

Note: The underlying mg_timer is automatically freed by Mongoose when it completes (via MG_TIMER_AUTODELETE flag). This class only manages the Python callback reference.

Source code in src/cymongoose/_mongoose.pyi 
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class Timer:
    """Wrapper for Mongoose timer.

    Note: The underlying mg_timer is automatically freed by Mongoose when it completes
    (via MG_TIMER_AUTODELETE flag). This class only manages the Python callback reference.
    """

    ...

Overview

Timer wraps Mongoose timers. Timers are automatically freed when they complete (MG_TIMER_AUTODELETE flag).

Note

Do not create Timer objects directly. Use Manager.timer_add().

Example

# One-shot timer
timer = manager.timer_add(5000, lambda: print("Hello"))

# Repeating timer
counter = 0
def heartbeat():
    global counter
    counter += 1
    print(f"Heartbeat #{counter}")

timer = manager.timer_add(1000, heartbeat, repeat=True)

# Run immediately and repeat
timer = manager.timer_add(1000, callback, repeat=True, run_now=True)

Event Data Types

Different events provide different data types:

Event Data Type Description
MG_EV_ERROR str Error message
MG_EV_RESOLVE None DNS resolved (check conn.remote_addr)
MG_EV_HTTP_MSG HttpMessage Complete HTTP message
MG_EV_HTTP_HDRS HttpMessage HTTP headers only
MG_EV_WS_OPEN HttpMessage WebSocket handshake request
MG_EV_WS_MSG WsMessage WebSocket frame
MG_EV_MQTT_MSG MqttMessage MQTT message
MG_EV_MQTT_CMD MqttMessage MQTT command
MG_EV_MQTT_OPEN int Connection status code
MG_EV_SNTP_TIME int Milliseconds since epoch
MG_EV_WAKEUP bytes Wakeup payload data
Others None No data

See Also

  • Connection - Connection class
  • Manager - Manager class
  • Guide - Protocol guides