* Rewrite the v4 What's New page
Teach the headline features with code instead of asserting them, drop the
major-version throat-clearing and SEP list, and correct the elicitation
claim: ctx.elicit() is unchanged and handshake-only, while sampling and
roots are removed outright.
* Fix broken doc links and stale version references
Repoint five dead links and anchors, refresh v3-era version examples on the
v4 docs, and add the missing FastMCP 3 entry to the installation page's
upgrade section.
* Document server extensions
add_extension() shipped in v4 with no documentation page. Covers the
extension interface, request methods, tool-call interception, lifespan
ownership, and the client half.
* Link the FastMCP TypeScript library
* Address Codex review feedback
Gate the extension interceptor on the client's per-request opt-in rather
than claiming negotiation does it; show the v4 beta pin on the install
page instead of a version a reader cannot get; note that UserSession
requires authentication.
* Always emit a tool title, derived from name when unset
Some MCP clients (e.g. ChatGPT) drop tools with no `title` instead of
falling back to `name` for display as the spec allows. Deriving a
default title in Tool.to_mcp_tool() fixes this for every tool built on
top of it, including the search-transform, code-mode, and session
proxy tools that never set one explicitly.
Fixes#4414
* Derive fallback title from the overridden name, document it
Addresses Codex review on #4694.
* Resolve title precedence from effective overrides
* Normalize mapping annotations before deriving the title
* Remove 3.x-era compatibility shims
* Require response_type in ctx.elicit()
* Name the utilities path for the two non-re-exported auth helpers
* Point sampling handler migration at its submodule
fastmcp.types re-exported 29 mcp_types symbols verbatim, which was
pointless indirection users had to discover. It now holds only Textarea,
the one type FastMCP actually defines; everything else imports from
mcp_types directly. These mirrors were added during unreleased SDK v2
migration work and never shipped, so this is not a breaking change.
* docs: align server component docs
Generated with Codex.
* docs: clarify resource return shapes
Generated with Codex.
* docs: clarify initialize middleware response
Generated with Codex.
* docs: lead visibility filtering with names, scope keys to version targeting
* docs: correct initialize result semantics, template mime type, docket scope, visibility tip
* Warn when a visibility key omits the @ version delimiter
* Honor a resource template's declared mime_type and meta on read
* Strip internal visibility meta from resource content; document filter intersection
---------
Co-authored-by: Jeremiah Lowin <153965+jlowin@users.noreply.github.com>
* Update repository references from jlowin/fastmcp to prefecthq/fastmcp
* Retrigger CI after repo transfer
* chore: Update SDK documentation
* Only run deep triage on bug issues for jlowin
---------
Co-authored-by: marvin-context-protocol[bot] <225465937+marvin-context-protocol[bot]@users.noreply.github.com>
Rename Visibility to Enabled, collapse VisibilityRule into the transform,
and move enabled filtering from Provider to Server level so server-level
transforms can override provider-level disables.
* Add comprehensive documentation for read-only tool patterns
Created new patterns guide explaining readOnlyHint annotation usage,
including practical examples, client-specific behavior, and best
practices for marking tools as read-only.
🤖 Generated with [Claude Code](https://claude.ai/code)
Co-authored-by: William Easton <strawgate@users.noreply.github.com>
* Reorganize read-only tools docs into tools section
Moved read-only tools documentation from standalone patterns page into the tools.mdx file as a "Using Annotation Hints" subsection. Condensed from 218 lines to ~50 lines focusing on practical usage while maintaining essential information about readOnlyHint and other annotations.
Changes:
- Added "Using Annotation Hints" subsection in tools.mdx after MCP Annotations
- Removed docs/patterns/read-only-tools.mdx
- Updated docs.json navigation to remove patterns entry
- Content now positioned as core tool feature rather than advanced pattern
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-authored-by: Bill Easton <strawgate@users.noreply.github.com>
---------
Co-authored-by: claude[bot] <41898282+claude[bot]@users.noreply.github.com>
Co-authored-by: William Easton <strawgate@users.noreply.github.com>
Fixes issue #2431 where exclude_args fails when excluded parameters have
non-serializable types (e.g., ServerSession). The fix excludes parameters
from function annotations before Pydantic tries to serialize them.
Also adds deprecation notice that exclude_args will be deprecated in
FastMCP 2.14 in favor of dependency injection.
- Restructured confusing sections: 'Object-like Results' → 'Dictionaries and Objects', 'Non-object Results' → 'Primitives and Collections', 'Complex Type Example' → 'Typed Models'
- Simplified CodeGroup examples to show Tool Definition + MCP Result instead of 3-4 confusing tabs
- Split Primitives/Collections into separate CodeGroups for clarity
- Renamed 'Full Control with ToolResult' → 'ToolResult and Metadata' for better TOC visibility
- Flattened ToolResult documentation with inline field descriptions instead of nested headings
- Added version badge for ToolResult meta field (2.13.1)
- Added clarification that ToolResult meta is separate from @mcp.tool meta
- Improved example server with realistic metadata (execution time, character/word counts)
- Fixed code formatting (multi-line objects, trailing commas)
* Add meta to ToolResult
* add this at the client level and test the full integration
* add example
* slipped through linting somehow
---------
Co-authored-by: Jeremiah Lowin <153965+jlowin@users.noreply.github.com>
* Implement icon support in fastmcp
* Fix icon feature tests
- Update snapshot for ResourceTemplate to include icons field
- Remove OAuth mounting tests (belong to PR #2119, not this feature)
* Update docs
Because the server now validates inputs, its no longer viable to provide a JSON string where e.g. an array is expected, so we can entirely remove FastMCP's "legacy json parsing" support from 1.x.
This is a breaking change (for legacy opt-in behavior)
Implements comprehensive notification system for tools, resources, and prompts with automatic client updates and flexible message handlers.
🤖 Generated with [Claude Code](https://claude.ai/code)
Co-Authored-By: Claude <noreply@anthropic.com>
