{ "title": "MCP Client, Server, and Host - Reader FAQ", "schemaVersion": "1.0", "researchFreeze": "2026-08-25", "protocolRevision": "2026-07-28", "publicationNote": "All 59 answers are rendered visibly on the architecture cornerstone; this endpoint does not imply search-result eligibility.", "count": 59, "records": [ { "id": "R5-FAQ01", "question": "What is MCP?", "packageAnswer": "The Model Context Protocol is an application protocol through which MCP clients communicate with MCP servers that expose tools, resources, prompts and extensions. It uses JSON-RPC 2.0 message structures and versioned MCP methods and schemas.", "answer": "The Model Context Protocol is an application protocol through which MCP clients communicate with MCP servers that expose tools, resources, prompts and extensions. It uses JSON-RPC 2.0 message structures and versioned MCP methods and schemas.", "answerMarkdown": "The Model Context Protocol is an application protocol through which MCP clients communicate with MCP servers that expose tools, resources, prompts and extensions. It uses JSON-RPC 2.0 message structures and versioned MCP methods and schemas.", "packageSourceIds": [ "S008" ], "supplementalSourceIds": [], "sourceIds": [ "S130" ], "verified": "2026-08-25" }, { "id": "R5-FAQ02", "question": "What does MCP stand for?", "packageAnswer": "MCP stands for Model Context Protocol.", "answer": "MCP stands for Model Context Protocol.", "answerMarkdown": "MCP stands for Model Context Protocol.", "packageSourceIds": [], "supplementalSourceIds": [], "sourceIds": [], "verified": "2026-08-25" }, { "id": "R5-FAQ03", "question": "What is an MCP host?", "packageAnswer": "An MCP host is the user-facing application or service that manages models, context, permissions, and multiple MCP client relationships.", "answer": "An MCP host is the user-facing application or service that manages models, context, permissions, and multiple MCP client relationships.", "answerMarkdown": "An MCP host is the user-facing application or service that manages models, context, permissions, and multiple MCP client relationships.", "packageSourceIds": [ "S001" ], "supplementalSourceIds": [], "sourceIds": [ "S121" ], "verified": "2026-08-25" }, { "id": "R5-FAQ04", "question": "What is an MCP client?", "packageAnswer": "An MCP client is the protocol component created by a host for one logical relationship with one MCP server.", "answer": "An MCP client is the protocol component created by a host for one logical relationship with one MCP server.", "answerMarkdown": "An MCP client is the protocol component created by a host for one logical relationship with one MCP server.", "packageSourceIds": [ "S001" ], "supplementalSourceIds": [], "sourceIds": [ "S121" ], "verified": "2026-08-25" }, { "id": "R5-FAQ05", "question": "What is an MCP server?", "packageAnswer": "An MCP server implements the server side of MCP and exposes focused capabilities such as tools, resources, prompts or extensions.", "answer": "An MCP server implements the server side of MCP and exposes focused capabilities such as tools, resources, prompts or extensions.", "answerMarkdown": "An MCP server implements the server side of MCP and exposes focused capabilities such as tools, resources, prompts or extensions.", "packageSourceIds": [], "supplementalSourceIds": [], "sourceIds": [], "verified": "2026-08-25" }, { "id": "R5-FAQ06", "question": "What is the simplest host–client–server diagram?", "packageAnswer": "User → host → one MCP client per server → MCP server → underlying system.", "answer": "User → host → one MCP client per server → MCP server → underlying system.", "answerMarkdown": "User → host → one MCP client per server → MCP server → underlying system.", "packageSourceIds": [], "supplementalSourceIds": [], "sourceIds": [], "verified": "2026-08-25" }, { "id": "R5-FAQ07", "question": "Are host and client the same thing?", "packageAnswer": "No. A host manages the application, model, permissions and multiple clients. Each client handles one server’s protocol relationship.", "answer": "No. A host manages the application, model, permissions and multiple clients. Each client handles one server’s protocol relationship.", "answerMarkdown": "No. A host manages the application, model, permissions and multiple clients. Each client handles one server’s protocol relationship.", "packageSourceIds": [], "supplementalSourceIds": [], "sourceIds": [], "verified": "2026-08-25" }, { "id": "R5-FAQ08", "question": "Why do people call Claude Desktop an MCP client?", "packageAnswer": "It is convenient shorthand. Architecturally Claude Desktop is a host application containing MCP client implementations.", "answer": "It is convenient shorthand. When MCP functionality is configured, Claude Desktop is the host application: it contains local clients for desktop-extension servers or uses Anthropic-managed infrastructure for remote connectors. Those local and cloud-brokered mechanisms are distinct.", "answerMarkdown": "It is convenient shorthand. When MCP functionality is configured, Claude Desktop is the host application: it contains local clients for desktop-extension servers or uses Anthropic-managed infrastructure for remote connectors. Those local and cloud-brokered mechanisms are distinct.", "packageSourceIds": [ "S035", "S037", "S038" ], "supplementalSourceIds": [], "sourceIds": [ "S258", "S260", "S145" ], "verified": "2026-08-25", "editorialCorrection": "Current first-party product documentation normalization; raw package answer preserved in packageAnswer." }, { "id": "R5-FAQ09", "question": "Is ChatGPT an MCP host?", "packageAnswer": "When using supported MCP/app connector features, ChatGPT performs the host role and uses managed client infrastructure for remote servers. Availability is live-check required.", "answer": "When an MCP app is enabled in a supported ChatGPT web product mode, ChatGPT performs the host role and OpenAI-managed infrastructure provides remote MCP client behavior. Full write or modify MCP is beta for Business, Enterprise, and Edu; Pro developer mode supports read and fetch. ChatGPT does not connect directly to local servers; supported private or local servers use Secure MCP Tunnel.", "answerMarkdown": "When an MCP app is enabled in a supported ChatGPT web product mode, ChatGPT performs the host role and OpenAI-managed infrastructure provides remote MCP client behavior. Full write or modify MCP is beta for Business, Enterprise, and Edu; Pro developer mode supports read and fetch. ChatGPT does not connect directly to local servers; supported private or local servers use [Secure MCP Tunnel](https://developers.openai.com/api/docs/guides/secure-mcp-tunnels).", "packageSourceIds": [ "S040" ], "supplementalSourceIds": [ "S261" ], "sourceIds": [ "S140", "S261" ], "verified": "2026-08-25", "editorialCorrection": "Current first-party product documentation normalization; raw package answer preserved in packageAnswer." }, { "id": "R5-FAQ10", "question": "Is VS Code an MCP host or client?", "packageAnswer": "VS Code is best classified as a host containing MCP clients for configured servers.", "answer": "In MCP role terminology, the VS Code agent experience is a host containing clients for configured servers. Microsoft’s separately named Agent Host is an AHP runtime or process; an MCP relationship may run in the extension host or Agent Host without changing the protocol-role classification.", "answerMarkdown": "In MCP role terminology, the VS Code agent experience is a host containing clients for configured servers. Microsoft’s separately named [Agent Host](https://code.visualstudio.com/docs/agents/concepts/agent-host) is an AHP runtime or process; an MCP relationship may run in the extension host or Agent Host without changing the protocol-role classification.", "packageSourceIds": [ "S043" ], "supplementalSourceIds": [ "S270" ], "sourceIds": [ "S141", "S270" ], "verified": "2026-08-25", "editorialCorrection": "Current first-party product documentation normalization; raw package answer preserved in packageAnswer." }, { "id": "R5-FAQ11", "question": "Is Cursor an MCP host or client?", "packageAnswer": "Cursor is a host/editor containing MCP client functionality for configured servers.", "answer": "Cursor IDE/Agent Window and Cursor CLI are distinct host surfaces that consume configured MCP servers and share MCP configuration. Neither surface is thereby the configured server, and this classification does not generalize to Cursor Cloud Agents.", "answerMarkdown": "Cursor IDE/Agent Window and Cursor CLI are distinct host surfaces that consume configured MCP servers and share MCP configuration. Neither surface is thereby the configured server, and this classification does not generalize to Cursor Cloud Agents.", "packageSourceIds": [ "S051" ], "supplementalSourceIds": [ "S283" ], "sourceIds": [ "S269", "S283" ], "verified": "2026-08-25", "editorialCorrection": "Current first-party product documentation normalization; raw package answer preserved in packageAnswer." }, { "id": "R5-FAQ12", "question": "Is Gemini CLI an MCP host?", "packageAnswer": "Yes. It coordinates the model, user permissions and configured MCP server tools while containing MCP client behavior.", "answer": "Yes. It coordinates the model, user permissions and configured MCP server tools while containing MCP client behavior.", "answerMarkdown": "Yes. It coordinates the model, user permissions and configured MCP server tools while containing MCP client behavior.", "packageSourceIds": [ "S052" ], "supplementalSourceIds": [], "sourceIds": [ "S144" ], "verified": "2026-08-25" }, { "id": "R5-FAQ13", "question": "Can one product be both an MCP client and server?", "packageAnswer": "Yes. Claude Code and JetBrains provide current examples of products or suites implementing consumer and provider roles in different relationships.", "answer": "Yes. Claude Code and JetBrains provide current examples of products or suites implementing consumer and provider roles in different relationships.", "answerMarkdown": "Yes. Claude Code and JetBrains provide current examples of products or suites implementing consumer and provider roles in different relationships.", "packageSourceIds": [ "S036", "S058" ], "supplementalSourceIds": [], "sourceIds": [ "S259", "S275" ], "verified": "2026-08-25" }, { "id": "R5-FAQ14", "question": "Can one host connect to multiple MCP servers?", "packageAnswer": "Yes. A host creates and manages multiple isolated client relationships.", "answer": "Yes. A host creates and manages multiple isolated client relationships.", "answerMarkdown": "Yes. A host creates and manages multiple isolated client relationships.", "packageSourceIds": [ "S001" ], "supplementalSourceIds": [], "sourceIds": [ "S121" ], "verified": "2026-08-25" }, { "id": "R5-FAQ15", "question": "Can one MCP client connect to multiple servers?", "packageAnswer": "The architecture scopes one logical client relationship to one server. A host creates multiple clients for multiple servers.", "answer": "The architecture scopes one logical client relationship to one server. A host creates multiple clients for multiple servers.", "answerMarkdown": "The architecture scopes one logical client relationship to one server. A host creates multiple clients for multiple servers.", "packageSourceIds": [], "supplementalSourceIds": [], "sourceIds": [], "verified": "2026-08-25" }, { "id": "R5-FAQ16", "question": "Can one MCP server serve many clients?", "packageAnswer": "Yes. A remote logical server may serve many clients and users, subject to authorization, capacity and tenant isolation.", "answer": "Yes. A remote logical server may serve many clients and users, subject to authorization, capacity and tenant isolation.", "answerMarkdown": "Yes. A remote logical server may serve many clients and users, subject to authorization, capacity and tenant isolation.", "packageSourceIds": [], "supplementalSourceIds": [], "sourceIds": [], "verified": "2026-08-25" }, { "id": "R5-FAQ17", "question": "Does one MCP client equal one network connection?", "packageAnswer": "No. Client is a logical protocol role; HTTP connections may be pooled, replaced or multiplexed.", "answer": "No. Client is a logical protocol role; HTTP connections may be pooled, replaced or multiplexed.", "answerMarkdown": "No. Client is a logical protocol role; HTTP connections may be pooled, replaced or multiplexed.", "packageSourceIds": [], "supplementalSourceIds": [], "sourceIds": [], "verified": "2026-08-25" }, { "id": "R5-FAQ18", "question": "Does one MCP server equal one process?", "packageAnswer": "No. A local server often is one process, while a remote logical server may have many replicas.", "answer": "No. A local server often is one process, while a remote logical server may have many replicas.", "answerMarkdown": "No. A local server often is one process, while a remote logical server may have many replicas.", "packageSourceIds": [], "supplementalSourceIds": [], "sourceIds": [], "verified": "2026-08-25" }, { "id": "R5-FAQ19", "question": "Where does the LLM run?", "packageAnswer": "The model normally operates through the host or its model provider. It is not a required component of the MCP client or server.", "answer": "The model normally operates through the host or its model provider. It is not a required component of the MCP client or server.", "answerMarkdown": "The model normally operates through the host or its model provider. It is not a required component of the MCP client or server.", "packageSourceIds": [], "supplementalSourceIds": [], "sourceIds": [], "verified": "2026-08-25" }, { "id": "R5-FAQ20", "question": "Does the LLM connect directly to an MCP server?", "packageAnswer": "Usually no. The host interprets model tool calls, applies policy and invokes the MCP client.", "answer": "Usually no. The host interprets model tool calls, applies policy and invokes the MCP client.", "answerMarkdown": "Usually no. The host interprets model tool calls, applies policy and invokes the MCP client.", "packageSourceIds": [], "supplementalSourceIds": [], "sourceIds": [], "verified": "2026-08-25" }, { "id": "R5-FAQ21", "question": "Can MCP work without an LLM?", "packageAnswer": "Yes. Deterministic software can list tools, call tools or read resources programmatically.", "answer": "Yes. Deterministic software can list tools, call tools or read resources programmatically.", "answerMarkdown": "Yes. Deterministic software can list tools, call tools or read resources programmatically.", "packageSourceIds": [], "supplementalSourceIds": [], "sourceIds": [], "verified": "2026-08-25" }, { "id": "R5-FAQ22", "question": "Who decides which MCP tools the model sees?", "packageAnswer": "The host filters and maps the server’s tool definitions into the model-facing tool set.", "answer": "The host filters and maps the server’s tool definitions into the model-facing tool set.", "answerMarkdown": "The host filters and maps the server’s tool definitions into the model-facing tool set.", "packageSourceIds": [], "supplementalSourceIds": [], "sourceIds": [], "verified": "2026-08-25" }, { "id": "R5-FAQ23", "question": "Who selects an MCP tool?", "packageAnswer": "A host may select it programmatically, or a model may select it through the host’s native tool-calling mechanism.", "answer": "A host may select it programmatically, or a model may select it through the host’s native tool-calling mechanism.", "answerMarkdown": "A host may select it programmatically, or a model may select it through the host’s native tool-calling mechanism.", "packageSourceIds": [], "supplementalSourceIds": [], "sourceIds": [], "verified": "2026-08-25" }, { "id": "R5-FAQ24", "question": "Who executes an MCP tool?", "packageAnswer": "The server executes the operation or delegates it to an underlying system.", "answer": "The server executes the operation or delegates it to an underlying system.", "answerMarkdown": "The server executes the operation or delegates it to an underlying system.", "packageSourceIds": [], "supplementalSourceIds": [], "sourceIds": [], "verified": "2026-08-25" }, { "id": "R5-FAQ25", "question": "Does the MCP client execute the tool?", "packageAnswer": "Usually no. The client transports tools/call; the server implements the effect.", "answer": "Usually no. The client transports tools/call; the server implements the effect.", "answerMarkdown": "Usually no. The client transports `tools/call`; the server implements the effect.", "packageSourceIds": [], "supplementalSourceIds": [], "sourceIds": [], "verified": "2026-08-25" }, { "id": "R5-FAQ26", "question": "Who shows a confirmation dialog?", "packageAnswer": "The host normally owns the user-facing confirmation interface.", "answer": "The host normally owns the user-facing confirmation interface.", "answerMarkdown": "The host normally owns the user-facing confirmation interface.", "packageSourceIds": [], "supplementalSourceIds": [], "sourceIds": [], "verified": "2026-08-25" }, { "id": "R5-FAQ27", "question": "Does host confirmation replace server authorization?", "packageAnswer": "No. Confirmation records user intent; the server and backend must still enforce object, tenant and business authorization.", "answer": "No. Confirmation records user intent; the server and backend must still enforce object, tenant and business authorization.", "answerMarkdown": "No. Confirmation records user intent; the server and backend must still enforce object, tenant and business authorization.", "packageSourceIds": [], "supplementalSourceIds": [], "sourceIds": [], "verified": "2026-08-25" }, { "id": "R5-FAQ28", "question": "Does the MCP server see the full conversation?", "packageAnswer": "Not by default. The host sends only the context and arguments needed for that server.", "answer": "Not by default. The host sends only the context and arguments needed for that server.", "answerMarkdown": "Not by default. The host sends only the context and arguments needed for that server.", "packageSourceIds": [ "S001" ], "supplementalSourceIds": [], "sourceIds": [ "S121" ], "verified": "2026-08-25" }, { "id": "R5-FAQ29", "question": "What is server isolation?", "packageAnswer": "It is the design principle that one server should not automatically see peer-server data or the host’s complete conversation.", "answer": "It is the design principle that one server should not automatically see peer-server data or the host’s complete conversation.", "answerMarkdown": "It is the design principle that one server should not automatically see peer-server data or the host’s complete conversation.", "packageSourceIds": [], "supplementalSourceIds": [], "sourceIds": [], "verified": "2026-08-25" }, { "id": "R5-FAQ30", "question": "What is an MCP capability?", "packageAnswer": "A capability declares supported protocol behavior. Current clients carry relevant client capabilities per request; servers report support through discovery and method behavior.", "answer": "A capability declares supported protocol behavior. Current clients carry relevant client capabilities per request; servers report support through discovery and method behavior.", "answerMarkdown": "A capability declares supported protocol behavior. Current clients carry relevant client capabilities per request; servers report support through discovery and method behavior.", "packageSourceIds": [], "supplementalSourceIds": [], "sourceIds": [], "verified": "2026-08-25" }, { "id": "R5-FAQ31", "question": "How were MCP capabilities negotiated before 2026?", "packageAnswer": "Legacy clients and servers exchanged capabilities during initialize, and the negotiated state applied to the session.", "answer": "Legacy clients and servers exchanged capabilities during initialize, and the negotiated state applied to the session.", "answerMarkdown": "Legacy clients and servers exchanged capabilities during `initialize`, and the negotiated state applied to the session.", "packageSourceIds": [ "S018", "S022" ], "supplementalSourceIds": [], "sourceIds": [ "S026", "S160" ], "verified": "2026-08-25" }, { "id": "R5-FAQ32", "question": "How are capabilities handled in current MCP?", "packageAnswer": "Client capabilities and protocol version are supplied per request; clients may use server/discover to learn server support.", "answer": "Client capabilities and protocol version are supplied per request; clients may use server/discover to learn server support.", "answerMarkdown": "Client capabilities and protocol version are supplied per request; clients may use `server/discover` to learn server support.", "packageSourceIds": [ "S003", "S004" ], "supplementalSourceIds": [], "sourceIds": [ "S056", "S127" ], "verified": "2026-08-25" }, { "id": "R5-FAQ33", "question": "What is server/discover?", "packageAnswer": "It is a current client-to-server method returning supported versions, server capabilities and self-reported server information.", "answer": "It is a current client-to-server method returning supported versions, server capabilities and self-reported server information.", "answerMarkdown": "It is a current client-to-server method returning supported versions, server capabilities and self-reported server information.", "packageSourceIds": [ "S004" ], "supplementalSourceIds": [], "sourceIds": [ "S127" ], "verified": "2026-08-25" }, { "id": "R5-FAQ34", "question": "Does server/discover authenticate a server?", "packageAnswer": "No. Its server information is self-reported and must not be treated as sufficient identity proof.", "answer": "No. Its server information is self-reported and must not be treated as sufficient identity proof.", "answerMarkdown": "No. Its server information is self-reported and must not be treated as sufficient identity proof.", "packageSourceIds": [], "supplementalSourceIds": [], "sourceIds": [], "verified": "2026-08-25" }, { "id": "R5-FAQ35", "question": "Is server/discover required?", "packageAnswer": "Current servers must implement it; clients may attempt another method directly and handle version errors.", "answer": "Current servers must implement it; clients may attempt another method directly and handle version errors.", "answerMarkdown": "Current servers must implement it; clients may attempt another method directly and handle version errors.", "packageSourceIds": [ "S004" ], "supplementalSourceIds": [], "sourceIds": [ "S127" ], "verified": "2026-08-25" }, { "id": "R5-FAQ36", "question": "What happened to initialize?", "packageAnswer": "It remains in legacy revisions through 2025-11-25 but was removed in 2026-07-28.", "answer": "It remains in legacy revisions through 2025-11-25 but was removed in 2026-07-28.", "answerMarkdown": "It remains in legacy revisions through `2025-11-25` but was removed in `2026-07-28`.", "packageSourceIds": [ "S002" ], "supplementalSourceIds": [], "sourceIds": [ "S055" ], "verified": "2026-08-25" }, { "id": "R5-FAQ37", "question": "What happened to notifications/initialized?", "packageAnswer": "It was removed with the initialization lifecycle in 2026-07-28.", "answer": "It was removed with the initialization lifecycle in 2026-07-28.", "answerMarkdown": "It was removed with the initialization lifecycle in `2026-07-28`.", "packageSourceIds": [ "S002" ], "supplementalSourceIds": [], "sourceIds": [ "S055" ], "verified": "2026-08-25" }, { "id": "R5-FAQ38", "question": "What happened to Mcp-Session-Id?", "packageAnswer": "The current protocol removed it along with protocol-level sessions.", "answer": "The current protocol removed it along with protocol-level sessions.", "answerMarkdown": "The current protocol removed it along with protocol-level sessions.", "packageSourceIds": [ "S002" ], "supplementalSourceIds": [], "sourceIds": [ "S055" ], "verified": "2026-08-25" }, { "id": "R5-FAQ39", "question": "Is MCP stateless now?", "packageAnswer": "The modern protocol core is request-stateless. Applications and backends can still maintain explicit state.", "answer": "The modern protocol core is request-stateless. Applications and backends can still maintain explicit state.", "answerMarkdown": "The modern protocol core is request-stateless. Applications and backends can still maintain explicit state.", "packageSourceIds": [], "supplementalSourceIds": [], "sourceIds": [], "verified": "2026-08-25" }, { "id": "R5-FAQ40", "question": "Does stateless MCP support multi-step workflows?", "packageAnswer": "Yes. Servers can use explicit handles, Tasks, databases or external jobs, and MRTR can obtain additional input.", "answer": "Yes. Servers can use explicit handles, Tasks, databases or external jobs, and MRTR can obtain additional input.", "answerMarkdown": "Yes. Servers can use explicit handles, Tasks, databases or external jobs, and MRTR can obtain additional input.", "packageSourceIds": [], "supplementalSourceIds": [], "sourceIds": [], "verified": "2026-08-25" }, { "id": "R5-FAQ41", "question": "What is an explicit state handle?", "packageAnswer": "It is a server-generated identifier returned to the host and supplied in later calls, with server-side authorization and expiry.", "answer": "It is a server-generated identifier returned to the host and supplied in later calls, with server-side authorization and expiry.", "answerMarkdown": "It is a server-generated identifier returned to the host and supplied in later calls, with server-side authorization and expiry.", "packageSourceIds": [ "S009" ], "supplementalSourceIds": [], "sourceIds": [ "S123" ], "verified": "2026-08-25" }, { "id": "R5-FAQ42", "question": "What is Multi Round-Trip Requests?", "packageAnswer": "MRTR is the current pattern in which a server returns inputrequired; the host obtains input and the client retries the original request with explicit state and responses.", "answer": "MRTR is the current pattern in which a server returns inputrequired; the host obtains input and the client retries the original request with explicit state and responses.", "answerMarkdown": "MRTR is the current pattern in which a server returns `input_required`; the host obtains input and the client retries the original request with explicit state and responses.", "packageSourceIds": [], "supplementalSourceIds": [], "sourceIds": [], "verified": "2026-08-25" }, { "id": "R5-FAQ43", "question": "Can servers still ask users for information?", "packageAnswer": "Yes, through host-mediated elicitation and MRTR rather than relying on ordinary server-initiated JSON-RPC requests.", "answer": "Yes, through host-mediated elicitation and MRTR rather than relying on ordinary server-initiated JSON-RPC requests.", "answerMarkdown": "Yes, through host-mediated elicitation and MRTR rather than relying on ordinary server-initiated JSON-RPC requests.", "packageSourceIds": [ "S012" ], "supplementalSourceIds": [], "sourceIds": [ "S126" ], "verified": "2026-08-25" }, { "id": "R5-FAQ44", "question": "Can MCP servers send notifications?", "packageAnswer": "Yes, through supported subscription mechanisms. Current notification delivery is explicit and scoped.", "answer": "Yes, through supported subscription mechanisms. Current notification delivery is explicit and scoped.", "answerMarkdown": "Yes, through supported subscription mechanisms. Current notification delivery is explicit and scoped.", "packageSourceIds": [], "supplementalSourceIds": [], "sourceIds": [], "verified": "2026-08-25" }, { "id": "R5-FAQ45", "question": "Does MCP use JSON-RPC?", "packageAnswer": "Yes. MCP uses JSON-RPC 2.0 message structures but adds its own methods, schemas, capabilities, versioning and transports.", "answer": "Yes. MCP uses JSON-RPC 2.0 message structures but adds its own methods, schemas, capabilities, versioning and transports.", "answerMarkdown": "Yes. MCP uses JSON-RPC 2.0 message structures but adds its own methods, schemas, capabilities, versioning and transports.", "packageSourceIds": [ "S008", "S034" ], "supplementalSourceIds": [], "sourceIds": [ "S130", "S001" ], "verified": "2026-08-25" }, { "id": "R5-FAQ46", "question": "What transport does local MCP use?", "packageAnswer": "stdio is common: the client launches the server subprocess and exchanges newline-delimited JSON-RPC over stdin/stdout.", "answer": "stdio is common: the client launches the server subprocess and exchanges newline-delimited JSON-RPC over stdin/stdout.", "answerMarkdown": "stdio is common: the client launches the server subprocess and exchanges newline-delimited JSON-RPC over stdin/stdout.", "packageSourceIds": [ "S006" ], "supplementalSourceIds": [], "sourceIds": [ "S132" ], "verified": "2026-08-25" }, { "id": "R5-FAQ47", "question": "What transport does remote MCP use?", "packageAnswer": "Current remote MCP commonly uses Streamable HTTP over HTTPS.", "answer": "Current remote MCP commonly uses Streamable HTTP over HTTPS.", "answerMarkdown": "Current remote MCP commonly uses Streamable HTTP over HTTPS.", "packageSourceIds": [ "S007" ], "supplementalSourceIds": [], "sourceIds": [ "S131" ], "verified": "2026-08-25" }, { "id": "R5-FAQ48", "question": "Does Streamable HTTP require a persistent SSE connection?", "packageAnswer": "No. Current clients POST independent requests; responses may be JSON or request-scoped SSE, and explicit subscriptions may use streams.", "answer": "No. Current clients POST independent requests; responses may be JSON or request-scoped SSE, and explicit subscriptions may use streams.", "answerMarkdown": "No. Current clients POST independent requests; responses may be JSON or request-scoped SSE, and explicit subscriptions may use streams.", "packageSourceIds": [], "supplementalSourceIds": [], "sourceIds": [], "verified": "2026-08-25" }, { "id": "R5-FAQ49", "question": "What is the difference between logical server and server replica?", "packageAnswer": "The logical server is the capability/identity endpoint; replicas are implementation instances behind routing infrastructure.", "answer": "The logical server is the capability/identity endpoint; replicas are implementation instances behind routing infrastructure.", "answerMarkdown": "The logical server is the capability/identity endpoint; replicas are implementation instances behind routing infrastructure.", "packageSourceIds": [], "supplementalSourceIds": [], "sourceIds": [], "verified": "2026-08-25" }, { "id": "R5-FAQ50", "question": "What is the difference between an SDK and a client?", "packageAnswer": "An SDK is a library. A running object or component instantiated from it performs the client role.", "answer": "An SDK is a library. A running object or component instantiated from it performs the client role.", "answerMarkdown": "An SDK is a library. A running object or component instantiated from it performs the client role.", "packageSourceIds": [], "supplementalSourceIds": [], "sourceIds": [], "verified": "2026-08-25" }, { "id": "R5-FAQ51", "question": "What is the difference between a server package and server?", "packageAnswer": "A package is distributed code; it becomes a server only when run and participating in MCP.", "answer": "A package is distributed code; it becomes a server only when run and participating in MCP.", "answerMarkdown": "A package is distributed code; it becomes a server only when run and participating in MCP.", "packageSourceIds": [], "supplementalSourceIds": [], "sourceIds": [], "verified": "2026-08-25" }, { "id": "R5-FAQ52", "question": "What is the difference between connector and MCP server?", "packageAnswer": "Connector is product terminology. It may mean a managed client integration, remote server, gateway, package or full app.", "answer": "Connector is product terminology. It may mean a managed client integration, remote server, gateway, package or full app.", "answerMarkdown": "Connector is product terminology. It may mean a managed client integration, remote server, gateway, package or full app.", "packageSourceIds": [], "supplementalSourceIds": [], "sourceIds": [], "verified": "2026-08-25" }, { "id": "R5-FAQ53", "question": "Are MCP servers agents?", "packageAnswer": "Not inherently. An agent may use an MCP server, and a server may perform agentic work, but the roles are different.", "answer": "Not inherently. An agent may use an MCP server, and a server may perform agentic work, but the roles are different.", "answerMarkdown": "Not inherently. An agent may use an MCP server, and a server may perform agentic work, but the roles are different.", "packageSourceIds": [], "supplementalSourceIds": [], "sourceIds": [], "verified": "2026-08-25" }, { "id": "R5-FAQ54", "question": "Are MCP resources tools?", "packageAnswer": "No. Resources are URI-addressed data/context; tools are callable operations.", "answer": "No. Resources are URI-addressed data/context; tools are callable operations.", "answerMarkdown": "No. Resources are URI-addressed data/context; tools are callable operations.", "packageSourceIds": [], "supplementalSourceIds": [], "sourceIds": [], "verified": "2026-08-25" }, { "id": "R5-FAQ55", "question": "Are MCP prompts system prompts?", "packageAnswer": "No. MCP prompts are server-exposed templates that a host may present or use.", "answer": "No. MCP prompts are server-exposed templates that a host may present or use.", "answerMarkdown": "No. MCP prompts are server-exposed templates that a host may present or use.", "packageSourceIds": [], "supplementalSourceIds": [], "sourceIds": [], "verified": "2026-08-25" }, { "id": "R5-FAQ56", "question": "Who controls MCP Apps?", "packageAnswer": "Servers provide app resources and tools; hosts negotiate, sandbox, render and mediate the UI.", "answer": "Servers provide app resources and tools; hosts negotiate, sandbox, render and mediate the UI.", "answerMarkdown": "Servers provide app resources and tools; hosts negotiate, sandbox, render and mediate the UI.", "packageSourceIds": [], "supplementalSourceIds": [], "sourceIds": [], "verified": "2026-08-25" }, { "id": "R5-FAQ57", "question": "Why can the same MCP server behave differently in two hosts?", "packageAnswer": "Hosts differ in model, supported capabilities, tool filtering, confirmation, authorization, schema translation and rendering.", "answer": "Hosts differ in model, supported capabilities, tool filtering, confirmation, authorization, schema translation and rendering.", "answerMarkdown": "Hosts differ in model, supported capabilities, tool filtering, confirmation, authorization, schema translation and rendering.", "packageSourceIds": [], "supplementalSourceIds": [], "sourceIds": [], "verified": "2026-08-25" }, { "id": "R5-FAQ58", "question": "Does MCP compatibility guarantee every feature works?", "packageAnswer": "No. Optional capabilities, extensions and product limits must be tested.", "answer": "No. Optional capabilities, extensions and product limits must be tested.", "answerMarkdown": "No. Optional capabilities, extensions and product limits must be tested.", "packageSourceIds": [], "supplementalSourceIds": [], "sourceIds": [], "verified": "2026-08-25" }, { "id": "R5-FAQ59", "question": "What is the current MCP specification?", "packageAnswer": "As verified on August 25, 2026, the current released revision is 2026-07-28. This is live-check required.", "answer": "As verified on August 25, 2026, the current released revision is 2026-07-28. This is live-check required.", "answerMarkdown": "As verified on August 25, 2026, the current released revision is `2026-07-28`. This is live-check required.", "packageSourceIds": [], "supplementalSourceIds": [], "sourceIds": [], "verified": "2026-08-25" } ] }