Mcp Chilkat2 PHP Reference Documentation

Mcp

Current Version: 11.7.0

Markdown version of this page for AI tools (v 11.7.0) · all AI docs

Chilkat.Mcp

A client for the Model Context Protocol (MCP).

Chilkat.Mcp connects to an MCP server and gives an application access to the server's tools, resources, and prompts over a single, unified API. MCP is an open protocol that standardizes how applications supply context and callable tools to AI models.

Connect & handshake

Connect opens a Streamable HTTP session and performs the MCP initialize handshake, negotiating the protocol version and establishing a session id.

Tools

List the server's tools with ListTools and invoke them with CallTool.

Resources & prompts

Read resources with ListResources and ReadResource, and fetch prompts with ListPrompts and GetPrompt.

Use with Chilkat.Ai

Pass a connected Chilkat.Mcp to Chilkat.Ai.UseMcp to register the server's tools with an AI model. During a conversation the model's tool calls are routed to the MCP server automatically.

Transport: This class uses the MCP Streamable HTTP transport (protocol version 2025-06-18). A server response may arrive as a single JSON object or as a Server-Sent-Events stream; both are handled transparently. The stdio transport is not supported.
Authentication: If the MCP server requires authorization, set the AuthToken property before calling Connect. Chilkat then sends it as an Authorization: Bearer <token> header on every request. Leave it unset for servers that do not require authentication.
Pagination: When a server has more items than fit in a single response, the tools/list, resources/list, and prompts/list results include a nextCursor string. In this release the list methods return the first page only and do not accept a cursor argument, so nextCursor is informational.

Object Creation

use Chilkat2\Mcp;

try {
    $mcp = new Mcp();
    // ... use $mcp ...
} catch (\Chilkat2\Exception $e) {
    echo $e->getClass(), '::', $e->getMethod(), " failed\n";
    echo $e->getMessage(), "\n";              // the LastErrorText of the failed call
}
public function __construct(array $properties = [])

Creates the object. The optional array sets properties in order, as if assigned one by one (new Mcp(['VerboseLogging' => true, 'RaiseError' => false])); an unknown or read-only name throws Error. The class is defined by the chilkat2 extension (extension=chilkat2 in php.ini): there is no PHP file to include.

There is no close(): PHP frees the object when its last reference goes (unset($mcp), $mcp = null, or the end of the function or request). Objects returned by methods are independent and freed the same way. The class may be extended (class MyMcp extends \Chilkat2\Mcp); objects cannot be cloned or serialized.

public bool $RaiseError;

When true (the default), a method that fails throws Chilkat2\Exception. When false, it returns false (or null) instead, and the reason is in LastErrorText. Objects returned by a method inherit the value of the object that returned them.

Errors

Chilkat2\Exception extends RuntimeException: getMessage() is the failed call's full LastErrorText, getClass() its class ('Chilkat2\Mcp') and getMethod() the method name. The object remains usable. Methods that look something up and find nothing return null without throwing (each such method says so), methods that answer a question (HasMember, IsUnlocked, ...) return a plain bool, and property reads and writes do not throw for Chilkat reasons.

Misuse always throws, whatever RaiseError is: a wrong argument type is a TypeError (exact types under declare(strict_types=1)), a missing or extra argument an ArgumentCountError, a string containing a NUL byte or an out-of-range integer a ValueError, and an unknown property (properties are case-sensitive) or a write to a read-only one an Error. Named arguments work with the parameter names shown.

Strings are passed and returned as UTF-8; binary data is a PHP string of bytes. Unlocking: call (new \Chilkat2\GlobalSettings())->UnlockBundle('...') once at startup.

Properties

AuthToken
public string $AuthToken;
Introduced in version 11.6.0

An optional bearer token for authenticating to the MCP server. When set, it is sent as an Authorization: Bearer <token> header on every request. The default is the empty string.

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Connected
public readonly bool $Connected;
Introduced in version 11.6.0

Read-only. true after a successful Connect (the initialize handshake completed).

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ConnectTimeoutMs
public int $ConnectTimeoutMs;
Introduced in version 11.6.0

The maximum amount of time, in milliseconds, to wait to establish the TCP/TLS connection to the MCP server. The default value is 30000 (30 seconds).

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DebugLogFilePath
public string $DebugLogFilePath;

If set to a file path, this property logs the LastErrorText of each Chilkat method or property call to the specified file. This logging helps identify the context and history of Chilkat calls leading up to any crash or hang, aiding in debugging.

Enabling the VerboseLogging property provides more detailed information. This property is mainly used for debugging rare instances where a Chilkat method call causes a hang or crash, which should generally not happen.

Possible causes of hangs include:

  • A timeout property set to 0, indicating an infinite timeout.
  • A hang occurring within an event callback in the application code.
  • An internal bug in the Chilkat code causing the hang.

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HeartbeatMs
public int $HeartbeatMs;
Introduced in version 11.6.0

The interval in milliseconds between each AbortCheck event callback, which enables an application to abort a method before it completes. By default, HeartbeatMs is 0, meaning no AbortCheck event callbacks fire.

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IdleTimeoutMs
public int $IdleTimeoutMs;
Introduced in version 11.6.0

The maximum amount of time, in milliseconds, to wait for additional incoming data when receiving a response has paused. This is not a total timeout. The default value is 180000 (180 seconds).

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LastErrorHtml
public readonly string $LastErrorHtml;

Provides HTML-formatted information about the last called method or property. If a method call fails or behaves unexpectedly, check this property for details. Note that information is available regardless of the method call's success.

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LastErrorText
public readonly string $LastErrorText;

Provides plain text information about the last called method or property. If a method call fails or behaves unexpectedly, check this property for details. Note that information is available regardless of the method call's success.

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LastErrorXml
public readonly string $LastErrorXml;

Provides XML-formatted information about the last called method or property. If a method call fails or behaves unexpectedly, check this property for details. Note that information is available regardless of the method call's success.

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LastMethodSuccess
public bool $LastMethodSuccess;

Indicates the success or failure of the most recent method call: true means success, false means failure. This property remains unchanged by property setters or getters. This method is present to address challenges in checking for null or Nothing returns in certain programming languages. Note: This property does not apply to methods that return integer values or to boolean-returning methods where the boolean does not indicate success or failure.

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ProtocolVersion
public string $ProtocolVersion;
Introduced in version 11.6.0

The MCP protocol version. May be set before Connect to request a specific version; after Connect it reflects the version negotiated with the server and is sent in the MCP-Protocol-Version header of each request. The default is 2025-06-18.

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ServerInstructions
public readonly string $ServerInstructions;
Introduced in version 11.6.0

Read-only. Optional usage instructions provided by the server in the initialize result (may be the empty string), available after Connect.

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ServerName
public readonly string $ServerName;
Introduced in version 11.6.0

Read-only. The server name reported in the initialize result, available after Connect.

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ServerVersion
public readonly string $ServerVersion;
Introduced in version 11.6.0

Read-only. The server version reported in the initialize result, available after Connect.

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SessionId
public readonly string $SessionId;
Introduced in version 11.6.0

Read-only. The Mcp-Session-Id assigned by the server during the Connect handshake, or the empty string if the server is stateless. Chilkat automatically includes this session id on all subsequent requests.

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VerboseLogging
public bool $VerboseLogging;

If set to true, then the contents of LastErrorText (or LastErrorXml, or LastErrorHtml) may contain more verbose information. The default value is false. Verbose logging should only be used for debugging. The potentially large quantity of logged information may adversely affect peformance.

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Version
public readonly string $Version;

Version of the component/library, such as "10.1.0"

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Methods

CallTool
public function CallTool(string $name, JsonObject $argsJson, JsonObject $resultJson): bool
Introduced in version 11.6.0

Calls the MCP tools/call method for the tool named $name, passing the JSON arguments object in $argsJson. The members of $argsJson are the tool's input arguments and should match the tool's inputSchema as returned by ListTools. For example, a weather tool might be called with the arguments { "location": "Boston, MA", "units": "fahrenheit" }. Pass an empty JSON object (not a null) for a tool that takes no arguments.

On success, the tool result is placed in $resultJson. It contains a content array, an isError boolean, and optionally a structuredContent object. Each element of the content array has a type ("text", "image", "audio", or "resource"); for a "text" element the value is in its text member. A typical result looks like:

{
  "content": [ { "type": "text", "text": "The weather in Boston is 72F and sunny." } ],
  "isError": false
}
Thus the text of the first content item is at JSON path content[0].text.

Note: A tool that executes but reports a failure returns true here with isError set to true in $resultJson (the failure message is typically carried in the content array). The return value is false only for transport- or protocol-level failures.

Connect must be called first.

Returns true on success. On failure it throws Chilkat2\Exception (or, with RaiseError set to false, returns false). $e->getMessage() (or the object's LastErrorText) explains why, and the object remains usable.

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Close
public function Close(): bool
Introduced in version 11.6.0

Explicitly terminates the MCP session by sending an HTTP DELETE with the Mcp-Session-Id header, then releases the connection. It is safe to call this method when not connected (it simply releases any transport). A server that does not permit client-terminated sessions responds with HTTP 405, which is not treated as an error.

Returns true on success. On failure it throws Chilkat2\Exception (or, with RaiseError set to false, returns false). $e->getMessage() (or the object's LastErrorText) explains why, and the object remains usable.

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Connect
public function Connect(string $url): bool
Introduced in version 11.6.0

Connects to the MCP (Model Context Protocol) server at the Streamable HTTP endpoint URL in $url (for example https://example.com/mcp) and performs the MCP initialize handshake.

On success, the SessionId, ProtocolVersion, ServerName, ServerVersion, and ServerInstructions properties are populated, and Connected becomes true.

If an AuthToken is set, it is sent as a bearer token on the request. The URL must begin with http:// or https://; the host, port, and path are taken from it. Only the Streamable HTTP transport is supported; the stdio transport is not.

Returns true on success. On failure it throws Chilkat2\Exception (or, with RaiseError set to false, returns false). $e->getMessage() (or the object's LastErrorText) explains why, and the object remains usable.

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GetLastJsonData
public function GetLastJsonData(JsonObject $json): void
Introduced in version 11.6.0

Returns, in $json, the complete JSON-RPC response envelope from the most recent request (the jsonrpc, id, and result or error members), for diagnostics and logging. Note that this is the full JSON-RPC envelope, whereas ListTools, CallTool, ReadResource, and GetPrompt each return only the inner result object.

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GetPrompt
public function GetPrompt(string $name, JsonObject $argsJson, JsonObject $json): bool
Introduced in version 11.6.0

Calls the MCP prompts/get method for the prompt named $name, passing the JSON arguments object in $argsJson (pass an empty object for a prompt that takes no arguments). On success, the result is placed in $json, consisting of an optional description and a messages array in which each message has a role and content.

Connect must be called first.

Returns true on success. On failure it throws Chilkat2\Exception (or, with RaiseError set to false, returns false). $e->getMessage() (or the object's LastErrorText) explains why, and the object remains usable.

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ListPrompts
public function ListPrompts(JsonObject $json): bool
Introduced in version 11.6.0

Calls the MCP prompts/list method. On success, the server's result object is placed in $json, containing a prompts array in which each prompt has a name, optionally a description, and an arguments array, and possibly a nextCursor for pagination.

Connect must be called first.

Returns true on success. On failure it throws Chilkat2\Exception (or, with RaiseError set to false, returns false). $e->getMessage() (or the object's LastErrorText) explains why, and the object remains usable.

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ListResources
public function ListResources(JsonObject $json): bool
Introduced in version 11.6.0

Calls the MCP resources/list method. On success, the server's result object is placed in $json, containing a resources array in which each resource has a uri, a name, and optionally a description and mimeType, and possibly a nextCursor for pagination.

Connect must be called first.

Returns true on success. On failure it throws Chilkat2\Exception (or, with RaiseError set to false, returns false). $e->getMessage() (or the object's LastErrorText) explains why, and the object remains usable.

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ListTools
public function ListTools(JsonObject $json): bool
Introduced in version 11.6.0

Calls the MCP tools/list method. On success, the server's result object is placed in $json, containing a tools array in which each tool has a name, a description, and an inputSchema (a JSON Schema describing the tool's arguments), and possibly a nextCursor for pagination.

Connect must be called first.

Returns true on success. On failure it throws Chilkat2\Exception (or, with RaiseError set to false, returns false). $e->getMessage() (or the object's LastErrorText) explains why, and the object remains usable.

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ReadResource
public function ReadResource(string $uri, JsonObject $json): bool
Introduced in version 11.6.0

Calls the MCP resources/read method for the resource identified by the URI in $uri. On success, the result is placed in $json, containing a contents array whose entries carry a uri, a mimeType, and either text (for text resources) or blob (base64 for binary resources).

Connect must be called first.

Returns true on success. On failure it throws Chilkat2\Exception (or, with RaiseError set to false, returns false). $e->getMessage() (or the object's LastErrorText) explains why, and the object remains usable.

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SetConnectionSettings
public function SetConnectionSettings(Socket $sock): bool
Introduced in version 11.6.0

Copies connection settings, including HTTP proxy, SOCKS proxy, bind (network interface) IP address, and TLS options, from $sock. This is optional; if not used, default settings apply. Call this method before Connect.

Returns true on success. On failure it throws Chilkat2\Exception (or, with RaiseError set to false, returns false). $e->getMessage() (or the object's LastErrorText) explains why, and the object remains usable.

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Events

All Chilkat methods are synchronous: the call returns when the work is done. During a long-running call, Mcp reports progress to handlers installed with three methods, each taking any PHP callable (a closure, an arrow function, $this->method(...), an invokable object) and returning the object, so the calls chain:

$mcp->onPercentDone(function (int $pctDone): bool {
        echo "$pctDone%\n";
        return false;           // return true to abort the method in progress
    })
    ->onProgressInfo(function (string $name, string $value): void {
        echo "$name: $value\n";
    });
$mcp->HeartbeatMs = 250;   // the AbortCheck handler is called 4 times per second
public function onAbortCheck(?callable $callback): static
public function onPercentDone(?callable $callback): static
public function onProgressInfo(?callable $callback): static

Each installs the handler for one event, replacing the one installed before; null removes it. A callable that does not exist is a TypeError right away.

The AbortCheck handler is called at the interval set by the HeartbeatMs property (0, the default, disables it); PercentDone is called when an operation's completion percentage is known; ProgressInfo delivers named progress values. A truthy return from the AbortCheck or PercentDone handler aborts the running method, which then fails in the usual way (Chilkat2\Exception, or false / null with RaiseError off). PHP's set_time_limit() does not interrupt a Chilkat call; an AbortCheck handler is how a script enforces its own limit.

Handlers run during the method call, in the same request. Inside a handler, the object's properties (such as $mcp->AbortCurrent = true) and other objects may be used, but calling a method of the same object throws Error. An exception thrown by a handler aborts the running method and propagates from it; the object remains usable. A closure that captures $mcp itself makes a reference cycle, which PHP's cycle collector frees.

AbortCheck
// handler: function (): bool -- return true to abort
public function onAbortCheck(?callable $callback): static

Enables a method call to be aborted by triggering the AbortCheck event at intervals defined by the HeartbeatMs property. If HeartbeatMs is set to its default value of 0, no events will occur. For instance, set HeartbeatMs to 200 to trigger 5 AbortCheck events per second.

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Example

$deadline = microtime(true) + 30;                     // give up after 30 seconds
$mcp->HeartbeatMs = 250;                       // call the handler 4 times per second
$mcp->onAbortCheck(fn(): bool => microtime(true) > $deadline);
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PercentDone
// handler: function (int $pctDone): bool -- return true to abort
public function onPercentDone(?callable $callback): static

This provides the percentage completion for any method involving network communications or time-consuming processing, assuming the progress can be measured as a percentage. This event is triggered only when it's possible and logical to express the operation's progress as a percentage. The pctDone argument will range from 1 to 100. For methods that finish quickly, the number of PercentDone callbacks may vary, but the final callback will have pctDone equal to 100. For longer operations, callbacks will not exceed one per percentage point (e.g., 1, 2, 3, ..., 98, 99, 100).

The PercentDone callback also acts as an AbortCheck event. For fast methods where PercentDone fires, an AbortCheck event may not trigger since the PercentDone callback already provides an opportunity to abort. For longer operations, where time between PercentDone callbacks is extended, AbortCheck callbacks enable more responsive operation termination.

To abort the operation, set the abort output argument to true. This will cause the method to terminate and return a failure status or corresponding failure value.

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Example

$mcp->onPercentDone(function (int $pctDone): bool {
    // $pctDone ranges from 0 to 100.
    echo "Percent done: $pctDone\n";
    return false;   // return true to abort the method in progress
});
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ProgressInfo
// handler: function (string $name, string $value): void
public function onProgressInfo(?callable $callback): static

This event callback provides tag name/value pairs that detail what occurs during a method call. To discover existing tag names, create code to handle the event, emit the pairs, and review them. Most tag names are self-explanatory.

Note: Some Chilkat methods don't fire any ProgressInfo events.

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Example

$mcp->onProgressInfo(function (string $name, string $value): void {
    echo "$name: $value\n";
});
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