878 pages for check.

Client Best Practices Model Context Protocol · in the page docs/draft/develop/clients/client-best-practices …en/agents-and-tools/tool-use/tool-search-tool) support this natively; check your provider's documentation for an equivalent. When available, you may prefer the platform's tool search over a custom imp… Connect to local MCP servers Model Context Protocol · in the page docs/draft/develop/connect-local-servers …running the latest version by clicking the Claude menu and selecting "Check for Updates..." ### Node.js The Filesystem Server and many other MCP servers require Node.js to run. Verify your Node.js i… Understanding MCP clients Model Context Protocol · in the page docs/draft/learn/client-concepts …information through appropriate UI controls (text fields, dropdowns, checkboxes), decline to provide information with optional explanation, or cancel the entire operation. Clients validate responses… Understanding MCP servers Model Context Protocol · in the page docs/draft/learn/server-concepts …levant information: * **Calendar data** (`calendar://events/2024`) - Checks user availability * **Travel documents** (`file:///Documents/Travel/passport.pdf`) - Accesses important documents * **Previ… SDKs Model Context Protocol · in the page docs/draft/sdk …anguage. SDKs adopt new protocol revisions on their own schedules, so check each SDK's documentation for the revisions it supports. All SDKs support: * Creating MCP servers that expose tools, resourc… Debugging Model Context Protocol · in the page docs/draft/tools/debugging …trictions ### Connection problems When servers fail to connect: 1. Check client logs 2. Verify server process is running 3. Test standalone with [Inspector](https://modelcontextprotocol.io/docs/dra… CLI client Model Context Protocol · in the page docs/draft/tools/inspector/cli …}`. | | `tools/list` | None | `--strict` turns its schema portability check into a gate (see [CI gates](#ci-gates)). | | `tools/call` | `--tool-name`, plus optional `--tool-arg` / `--tool-args-json` |… Configuration and flags Model Context Protocol · in the page docs/draft/tools/inspector/configuration …file you > didn't write: a coworker's, a client application's, or one checked into a > repo. It guarantees the Inspector will not touch the file. ### Ad-hoc targets Instead of a file you can name on… Recipes Model Context Protocol · in the page docs/draft/tools/inspector/recipes …o`, TUI), which is where most stdio servers put their diagnostics, so check there first when a connection fails for no visible reason. ### HTTP and SSE ```bash theme={null} mcp-inspector --server-ur… Security Model Context Protocol · in the page docs/draft/tools/inspector/security …* `Origin` header (curl, a script, any non-browser client) skips that check entirely. A `Host` header allow-list runs ahead of every route, including `GET /`, and answers `403` to a request whose `Hos… Web client Model Context Protocol · in the page docs/draft/tools/inspector/web …cripted launches), or set `DANGEROUSLY_OMIT_AUTH=true` to disable the check entirely, but only on a machine where nothing else can reach the port. Both are described under [Web backend environment var… Understanding Authorization in MCP Model Context Protocol · in the page docs/draft/tutorials/security/authorization …zation_response_iss_parameter_supported": true } ``` The client must check two of these values: * `issuer` must be identical to the issuer identifier used to build the metadata URL. If it isn't, the… Local Server Security Model Context Protocol · in the page docs/draft/tutorials/security/local-server-security …above). Before the mitigations, one fact that shapes them all: **no check proves what a server will do.** The protocol cannot guarantee that a server is what it claims or does only what it promises.… Security Best Practices Model Context Protocol · in the page docs/draft/tutorials/security/security_best_practices …Browser->>MCP: GET /authorize?client_id=...&redirect_uri=... alt Check MCP Server Consent MCP->>MCP: Check consent for this client_id Note over MCP: Not previously approved en… Build an MCP App Model Context Protocol · in the page extensions/apps/build …omprehensive. Other agents may support skills in different locations; check your agent's documentation. For example, with Claude Code you can install the skill globally (available in all projects):… Enterprise-Managed Authorization Model Context Protocol · in the page extensions/auth/enterprise-managed-authorization …y means validating JWT signatures against the IdP's JWKS endpoint and checking the token's audience, issuer, and expiration. 2. **Map IdP claims to permissions** — ID-JAG tokens carry claims (scope a… OAuth Client Credentials Model Context Protocol · in the page extensions/auth/oauth-client-credentials …crets in a secrets manager, never in source code or environment files checked into version control. > * Rotate secrets on a regular schedule and immediately after any suspected compromise. > * Scope c… Extension Support Matrix Model Context Protocol · in the page extensions/client-matrix …cked separately from the core MCP authorization features (DCR, CIMD). Check each extension's specification and the [ext-auth repository](https://github.com/modelcontextprotocol/ext-auth) for the lates… Extensions Overview Model Context Protocol · in the page extensions/overview …do so, so that extensions work consistently across protocol versions. Check that your SDK can send and receive this field, and that the extension supports the negotiated protocol version. If the other… Skills Model Context Protocol · in the page extensions/skills/overview …"code-review", "description": "Review code using the team's checklist." }, "resources": [ { "uri": "skill://code-review/SKILL.md", "digest":… Tasks Model Context Protocol · in the page extensions/tasks/overview …"io.modelcontextprotocol/tasks": {}, }, }, }, } ``` **2. Check client capabilities** Before returning a `CreateTaskResult`, verify that the client included the extension in its per-reque… The MCP Registry Model Context Protocol · in the page registry/about …gistry aggregators and marketplaces can implement additional security checks, ratings, or curation. The MCP Registry focuses on namespace authentication and metadata hosting, while relying on the bro… How to Automate Publishing with GitHub Actions Model Context Protocol · in the page registry/github-actions …or OIDC authentication contents: read steps: - name: Checkout code uses: actions/checkout@v5 ### Publish underlying npm package: - name: Set up Node.js u… MCP Registry Supported Package Types Model Context Protocol · in the page registry/package-types …Verification The MCP Registry verifies ownership of npm packages by checking `mcpName` in `package.json`. The `mcpName` property **MUST** match the server name from `server.json`. For example: ```j… SEP-1024: MCP Client Security Requirements for Local Server Installation Model Context Protocol · in the page seps/1024-mcp-client-security-requirements-for-local-server- …e explicit user approval through an affirmative action (button click, checkbox, etc.) 3. Provide an option for users to cancel the installation 4. Not proceed with installation if consent is denied… 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 …r `"url"`). ### Migration Path To ease migration: * Servers SHOULD check client capabilities before sending mode-specific requests * Clients MAY initially support only form mode to maintain compati… SEP-1303: Input Validation Errors as Tool Execution Errors Model Context Protocol · in the page seps/1303-input-validation-errors-as-tool-execution-errors …schema can only describe the regex statement. The actual programmatic check that the date is in the past cannot be expressed here as JSON schema. Even when a model provides a syntactically correct dat… SEP-1330: Elicitation Enum Schema Improvements and Standards Compliance Model Context Protocol · in the page seps/1330-elicitation-enum-schema-improvements-and-standards …iple entries. In the UI, this amounts to the difference between using checkboxes or radio buttons. For these reasons, we propose the following non-breaking minor improvements to the `EnumSchema` for… SEP-1686: Tasks Model Context Protocol · in the page seps/1686-tasks …eously. These complex, multi-step workflows require a way to actively check statuses, as they take upwards of several hours, making retries undesirable. ***Current Workaround:*** Not yet determined. *… SEP-1730: SDKs Tiering System Model Context Protocol · in the page seps/1730-sdks-tiering-system …mplement, we want to move forward with at least some automated way to check if SDK has a full set of features. We will start from Servers features set, as we have many more servers than clients and th… SEP-2085: Governance Succession and Amendment Procedures Model Context Protocol · in the page seps/2085-governance-succession-and-amendment …s. The current proposal allows for quick succession while maintaining checks through the existing maintainer structure. **Amendment by Any Maintainer**: Allowing any maintainer to propose amendments… SEP-2106: Tools `inputSchema` & `outputSchema` Conform to JSON Schema 2020-12 Model Context Protocol · in the page seps/2106-json-schema-2020-12 …?.["city"] as string; // previously compiled ``` will no longer type-check after the change, because TypeScript forbids property access on `unknown` without a narrowing guard: ```typescript theme={n… SEP-2133: Extensions Model Context Protocol · in the page seps/2133-extensions …"version": "1.0.0" } } } ``` #### Server-Side Capability Checking Servers SHOULD check client capabilities before offering extension-specific features: ```typescript theme={null} const… SEP-2148: MCP Contributor Ladder Model Context Protocol · in the page seps/2148-contributor-ladder …nation issue templates in `.github/ISSUE_TEMPLATE/` (see Appendix for checklist templates) 3. Updating `MAINTAINERS.md` format to reflect role distinctions ## Appendix: Checklist Templates ### Membe… SEP-2207: OIDC-Flavored Refresh Token Guidance Model Context Protocol · in the page seps/2207-oidc-refresh-token-guidance …fline_access`, including it would be semantically incorrect. ### Why check client metadata for grant types? Why not always issue refresh tokens? OAuth 2.1 requires clients to register their supporte… SEP-2243: HTTP Header Standardization for Streamable HTTP Transport Model Context Protocol · in the page seps/2243-http-standardization …boolean`: Convert to lowercase `"true"` or `"false"` 2. **Whitespace check**: If the string starts or ends with whitespace (space or tab): * Apply Base64 encoding (see below) 3. **ASCII validatio… SEP-2260: Require Server requests to be associated with a Client request. Model Context Protocol · in the page seps/2260-Require-Server-requests-to-be-associated-with-Client-requests …s a special status as it is primarily intended as a keep-alive/health-check mechanism. For Streamable HTTP Servers this enables SSE Streams to be maintained for extended periods if no Notifications o… SEP-2322: Multi Round-Trip Requests Model Context Protocol · in the page seps/2322-MRTR …l": 100 } } } ``` 3. **Client Request** periodically checks the status of the `Task` using `tasks/get`. ```json theme={null} { "jsonrpc": "2.0", "id": 2, "method… SEP-2468: Recommend Issuer (iss) Parameter in MCP Auth Responses Model Context Protocol · in the page seps/2468-recommend-issuer-claim-for-auth …nt has already validated per RFC 8414 §3.3, so a present `iss` can be checked against an authentic baseline; rejection on mismatch remains unconditional, so the only behavioral difference is accepting… SEP-2484: Require Conformance Tests for Standards Track SEPs to Reach Final Status Model Context Protocol · in the page seps/2484-conformance-tests-required-for-final-seps …aceability file mapping each MUST/MUST NOT and SHOULD/SHOULD NOT to a check or a documented exclusion. This keeps the conformance suite synchronized with the specification as it evolves, gives SDK mai… SEP-2549: TTL for List Results Model Context Protocol · in the page seps/2549-TTL-for-list-results …tic background refetches. The TTL is a **freshness hint**: the client checks freshness when it needs the list, and re-fetches only if stale. Implementations that do choose to poll SHOULD apply jitter… SEP-2567: Sessionless MCP via Explicit State Handles Model Context Protocol · in the page seps/2567-sessionless-mcp …he canonical example is a shopping cart: `add_item()`, `add_item()`, `checkout()`, with the cart existing implicitly per-session. This generalizes to any stateful workflow — a Playwright browser insta… SEP-2575: Make MCP Stateless Model Context Protocol · in the page seps/2575-stateless-mcp …lives, SSE comments, STDIO process status) handle connection-health checks more appropriately. ## Rationale ### Stateless-First by Default The primary design decision of this SEP is to remove the… SEP-2640: Skills Extension Model Context Protocol · in the page seps/2640-skills-extension …any conforming host. Because `resources` is complete, both limits are checkable from the entry alone, by counting entries and summing `size`, before the host retrieves a single file, and a host that d… SEP-2663: Tasks Extension Model Context Protocol · in the page seps/2663-tasks-extension …# Response Upon receiving a `tasks/get` request, the server **MUST** check the status of the task and respond accordingly: 1. If the status is `working`, the server **MUST** return a a `Task` object… SEP-3398: Release Cycle Updates Model Context Protocol · in the page seps/3398-release-cycle-updates …mplementation maintainers and run relevant regression and conformance checks before merging. Where observable protocol behavior changes, update applicable conformance coverage. 4. Record the vote, dec… SEP-985: Align OAuth 2.0 Protected Resource Metadata with RFC 9728 Model Context Protocol · in the page seps/985-align-oauth-20-protected-resource-metadata-with-rf …equest without a token. * If a 401 Unauthorized response is received: Check for a WWW-Authenticate header. If present and includes the resource\_metadata parameter, use it to locate the resource metad… 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 …aking detection difficult. Platform-specific attestations (iOS DeviceCheck, Android Play Integrity) could address this, but they're not universally available. This would work by a developer running a… Roots Model Context Protocol · in the page specification/2024-11-05/client/roots …e exposing * Monitor for root changes 2. Servers **SHOULD**: * Check for roots capability before usage * Handle root list changes gracefully * Respect root boundaries in operations * C… Resources Model Context Protocol · in the page specification/2024-11-05/server/resources …ta **MUST** be properly encoded 4. Resource permissions **SHOULD** be checked before operations