662 pages for credential.

Understanding MCP clients Model Context Protocol · in the page docs/2026-07-28/learn/client-concepts …he client, which makes this mode suitable for sensitive flows such as credential entry or third-party OAuth authorization. Elicitation follows the [Multi Round-Trip Requests](/specification/2026-07-2… Debugging Model Context Protocol · in the page docs/2026-07-28/tools/debugging …hen debugging: 1. **Sensitive Data** * Sanitize logs * Protect credentials * Mask personal information 2. **Access Control** * Verify permissions * Check authentication * Monitor a… Authorization Model Context Protocol · in the page docs/2026-07-28/tools/inspector/authorization …rization server supports dynamic redirect-URI registration. ## Where credentials live | File | Contents | | - | - | | `~/.mcp-inspector/storage/oauth.json` | Non-secret OAuth state (discovery metada… CLI client Model Context Protocol · in the page docs/2026-07-28/tools/inspector/cli …sensitive headers, > OAuth client secrets), but it does **not** scrub credentials embedded in a > server `url` (userinfo or query tokens) or in stdio `args`. Treat raw URL and > `detail` fields as sen… Configuration and flags Model Context Protocol · in the page docs/2026-07-28/tools/inspector/configuration …always persisted. | ## Where secrets are stored The Inspector keeps credentials out of `mcp.json`, `client.json` and `oauth.json`, so that sharing, committing or syncing those files does not leak th… mcpdo connection client Model Context Protocol · in the page docs/2026-07-28/tools/inspector/mcpdo …d stdio child) is re-dialed transparently on next use with the stored credentials. Only an `auth_required` error needs you to run `connect` again. A connection runs **one call at a time**. Commands a… Security Model Context Protocol · in the page docs/2026-07-28/tools/inspector/security …d the mcpdo daemon The Inspector is a developer tool that holds real credentials and starts real processes. This page gathers everything it protects, what it trusts, and where the boundaries sit, so… Understanding Authorization in MCP Model Context Protocol · in the page docs/2026-07-28/tutorials/security/authorization …tion/latest/basic/transports.md#stdio), you can use environment-based credentials or credentials provided by third-party libraries embedded directly in the MCP server instead. Because a STDIO-built MC… Local Server Security Model Context Protocol · in the page docs/2026-07-28/tutorials/security/local-server-security …variables, can read anything your account can read — SSH keys, cloud credentials, browser profiles, your home directory — and can open outbound network connections to anywhere. None of that is govern… Security Best Practices Model Context Protocol · in the page docs/2026-07-28/tutorials/security/security_best_practices …or traffic monitoring, that depend on the token audience or other credential constraints. If clients can obtain and use tokens directly with the downstream APIs without the MCP server vali… Client Best Practices Model Context Protocol · in the page docs/draft/develop/clients/client-best-practices …call, and returns the result to the sandbox. Authorization tokens and credentials are held by the host and never exposed to the generated code. **The model** sees only what the sandbox returns, typic… Understanding MCP clients Model Context Protocol · in the page docs/draft/learn/client-concepts …he client, which makes this mode suitable for sensitive flows such as credential entry or third-party OAuth authorization. Elicitation follows the [Multi Round-Trip Requests](/specification/draft/bas… Debugging Model Context Protocol · in the page docs/draft/tools/debugging …hen debugging: 1. **Sensitive Data** * Sanitize logs * Protect credentials * Mask personal information 2. **Access Control** * Verify permissions * Check authentication * Monitor a… Authorization Model Context Protocol · in the page docs/draft/tools/inspector/authorization …rization server supports dynamic redirect-URI registration. ## Where credentials live | File | Contents | | - | - | | `~/.mcp-inspector/storage/oauth.json` | Non-secret OAuth state (discovery metada… CLI client Model Context Protocol · in the page docs/draft/tools/inspector/cli …sensitive headers, > OAuth client secrets), but it does **not** scrub credentials embedded in a > server `url` (userinfo or query tokens) or in stdio `args`. Treat raw URL and > `detail` fields as sen… Configuration and flags Model Context Protocol · in the page docs/draft/tools/inspector/configuration …always persisted. | ## Where secrets are stored The Inspector keeps credentials out of `mcp.json`, `client.json` and `oauth.json`, so that sharing, committing or syncing those files does not leak th… mcpdo connection client Model Context Protocol · in the page docs/draft/tools/inspector/mcpdo …d stdio child) is re-dialed transparently on next use with the stored credentials. Only an `auth_required` error needs you to run `connect` again. A connection runs **one call at a time**. Commands a… Security Model Context Protocol · in the page docs/draft/tools/inspector/security …d the mcpdo daemon The Inspector is a developer tool that holds real credentials and starts real processes. This page gathers everything it protects, what it trusts, and where the boundaries sit, so… Understanding Authorization in MCP Model Context Protocol · in the page docs/draft/tutorials/security/authorization …tion/latest/basic/transports.md#stdio), you can use environment-based credentials or credentials provided by third-party libraries embedded directly in the MCP server instead. Because a STDIO-built MC… Local Server Security Model Context Protocol · in the page docs/draft/tutorials/security/local-server-security …variables, can read anything your account can read — SSH keys, cloud credentials, browser profiles, your home directory — and can open outbound network connections to anywhere. None of that is govern… Security Best Practices Model Context Protocol · in the page docs/draft/tutorials/security/security_best_practices …or traffic monitoring, that depend on the token audience or other credential constraints. If clients can obtain and use tokens directly with the downstream APIs without the MCP server vali… Enterprise-Managed Authorization Model Context Protocol · in the page extensions/auth/enterprise-managed-authorization …ions. Employees authenticate with their corporate identity — the same credentials they use for email, Slack, and other work tools — and the IdP grants or denies MCP server access based on organization… Authorization Extensions Model Context Protocol · in the page extensions/auth/overview …sions address these gaps. ## Available extensions > **[OAuth Client Credentials](/extensions/auth/oauth-client-credentials.md)** > > Machine-to-machine authentication using the OAuth 2.0 client cred… Extension Support Matrix Model Context Protocol · in the page extensions/client-matrix …HTML interfaces rendered inline in the conversation | | [OAuth Client Credentials](/extensions/auth/oauth-client-credentials.md) | `io.modelcontextprotocol/oauth-client-credentials` | Machine-to-machi… Extensions Overview Model Context Protocol · in the page extensions/overview …prefix}/{extension-name}`, e.g. `io.modelcontextprotocol/oauth-client-credentials`. Identifiers follow the same rules as [`_meta` keys](/specification/draft/basic/index#meta), with a mandatory prefix.… How to Authenticate When Publishing to the Official MCP Registry Model Context Protocol · in the page registry/authentication …yring="${MY_KEYRING}" --location=global # Enable Application Default Credentials (ADC) so the publisher tool can sign gcloud auth application-default login # Attempt login to show the public key mcp… SEP-1036: URL Mode Elicitation for secure out-of-band interactions Model Context Protocol · in the page seps/1036-url-mode-elicitation-for-secure-out-of-band-intera …cases that form mode elicitation cannot, such as gathering sensitive credentials, performing OAuth flows for external (3rd-party) authorization, and handling payments, *without* exposing sensitive da… SEP-2127: MCP Server Cards - HTTP Server Discovery Model Context Protocol · in the page seps/2127-mcp-server-cards …on disclosure**: Cards are public by design; servers MUST NOT include credentials, internal network topology, proprietary logic, or user/session-specific data. * **Primitive exclusion as a safety prop… SEP-2133: Extensions Model Context Protocol · in the page seps/2133-extensions …prefix}/{extension-name}`, e.g. `io.modelcontextprotocol/oauth-client-credentials` or `com.example/websocket-transport`. The names follow the same rules as the [\_meta keys](https://modelcontextprotoc… SEP-2567: Sessionless MCP via Explicit State Handles Model Context Protocol · in the page seps/2567-sessionless-mcp …clude varying the list by the authorization presented on the request: credentials are carried on each request, so a server returning different tool sets to different principals or scopes is relying on… SEP-991: Enable URL-based Client Registration using OAuth Client ID Metadata Documents Model Context Protocol · in the page seps/991-enable-url-based-client-registration-using-oauth-c …nts ship * Pre-registration by users creates poor UX requiring manual credential management * DCR requires servers to manage unbounded databases, handle expiration, and trust self-asserted metadata #… Specification Enhancement Proposals (SEPs) Model Context Protocol · in the page seps/index …rds Track | 2025-08-05 | | [SEP-1046](/seps/1046-support-oauth-client-credentials-flow-in-authoriza.md) | Support OAuth client credentials flow in authorization | Final | Standards Track | 2025-07-23… Logging Model Context Protocol · in the page specification/2024-11-05/server/utilities/logging …log messages ## Security 1. Log messages **MUST NOT** contain: * Credentials or secrets * Personal identifying information * Internal system details that could aid attacks 2. Implementatio… Authorization Model Context Protocol · in the page specification/2025-03-26/basic/authorization …port **SHOULD NOT** follow this specification, and instead retrieve credentials from the environment. * Implementations using alternative transports **MUST** follow established security best pract… Overview Model Context Protocol · in the page specification/2025-03-26/basic/index …nsport **SHOULD NOT** follow this specification, and instead retrieve credentials from the environment. Additionally, clients and servers **MAY** negotiate their own custom authentication and authori… Logging Model Context Protocol · in the page specification/2025-03-26/server/utilities/logging …log messages ## Security 1. Log messages **MUST NOT** contain: * Credentials or secrets * Personal identifying information * Internal system details that could aid attacks 2. Implementatio… Authorization Model Context Protocol · in the page specification/2025-06-18/basic/authorization …port **SHOULD NOT** follow this specification, and instead retrieve credentials from the environment. * Implementations using alternative transports **MUST** follow established security best pract… Overview Model Context Protocol · in the page specification/2025-06-18/basic/index …nsport **SHOULD NOT** follow this specification, and instead retrieve credentials from the environment. Additionally, clients and servers **MAY** negotiate their own custom authentication and authori… Logging Model Context Protocol · in the page specification/2025-06-18/server/utilities/logging …log messages ## Security 1. Log messages **MUST NOT** contain: * Credentials or secrets * Personal identifying information * Internal system details that could aid attacks 2. Implementatio… Authorization Model Context Protocol · in the page specification/2025-11-25/basic/authorization …port **SHOULD NOT** follow this specification, and instead retrieve credentials from the environment. * Implementations using alternative transports **MUST** follow established security best pract… Overview Model Context Protocol · in the page specification/2025-11-25/basic/index …nsport **SHOULD NOT** follow this specification, and instead retrieve credentials from the environment. Additionally, clients and servers **MAY** negotiate their own custom authentication and authori… Elicitation Model Context Protocol · in the page specification/2025-11-25/client/elicitation …nformation such as > passwords, API keys, access tokens, or payment credentials > * Servers **MUST** use [URL mode](#url-mode-elicitation-requests) for interactions involving > such sensitive info… Logging Model Context Protocol · in the page specification/2025-11-25/server/utilities/logging …log messages ## Security 1. Log messages **MUST NOT** contain: * Credentials or secrets * Personal identifying information * Internal system details that could aid attacks 2. Implementatio… Authorization Server Discovery Model Context Protocol · in the page specification/2026-07-28/basic/authorization/authorization-server-discovery …d them. Clients **MUST** maintain separate registration state (client credentials, tokens) per authorization server and **MUST NOT** assume that credentials valid for one authorization server will be… Client Registration Model Context Protocol · in the page specification/2026-07-28/basic/authorization/client-registration …Server->>User: Authentication prompt User->>Server: Provides credentials Note over Server: Authenticates user Note over Server: Detects URL-formatted client_id Server->>Metadata… Authorization Model Context Protocol · in the page specification/2026-07-28/basic/authorization/index …port **SHOULD NOT** follow this specification, and instead retrieve credentials from the environment. * Implementations using alternative transports **MUST** follow established security best pract… Overview Model Context Protocol · in the page specification/2026-07-28/basic/index …nsport **SHOULD NOT** follow this specification, and instead retrieve credentials from the environment. Additionally, clients and servers **MAY** negotiate their own custom authentication and authori… Key Changes Model Context Protocol · in the page specification/2026-07-28/changelog …ntextprotocol/modelcontextprotocol/pull/837)). 9. Clarify that client credentials are bound to the authorization server that issued them: clients **MUST** key persisted credentials by the issuer id… Elicitation Model Context Protocol · in the page specification/2026-07-28/client/elicitation …nformation such as > passwords, API keys, access tokens, or payment credentials > * Servers **MUST** use [URL mode](#url-mode-elicitation-requests) for interactions involving > such sensitive info… Prompts Model Context Protocol · in the page specification/2026-07-28/server/prompts …returning only the prompts the caller's granted scopes permit — since credentials are per-request input, not connection state. ## Protocol Messages ### Listing Prompts To retrieve available prompts…