Prepare SDK Tier 2 assessment submission

- Add CHANGELOG.md with release lines and history
- Refresh ROADMAP.md: 2.x stable line, 3.0.x for 2026-07-28 spec (first
  milestones Sep 2026), Tier 2 commitment, 1.x/0.x security-patches-only
- Refresh VALIDATION_RESULTS.md: 2026-08-17 run on conformance suite
  0.2.0-alpha.11 (server 73/73, auth 193/193, client 3/4 w/ sse-retry baselined)
- Bump conformance CI action pins v0.1.11 -> v0.1.16
- Update docs with missing features

Signed-off-by: Christian Tzolov <christian.tzolov@broadcom.com>
This commit is contained in:
Christian Tzolov 2026-08-17 19:57:29 +02:00 • committed by Daniel Garnier-Moiroux
commit 2fd159a79a

View file

@ -407,6 +407,40 @@ var server = McpServer.sync(transportProvider)
The embedded JSON Schema documents themselves (`Tool.inputSchema`, `Tool.outputSchema`, and elicitation `requestedSchema`) are validated against the JSON Schema 2020-12 meta-schema (SEP-1613). Malformed schemas are rejected at build time (`McpServer.build()`) and when calling `addTool()`, throwing an `IllegalArgumentException` that names the offending field. A schema that declares a different dialect via `$schema` is accepted without meta-schema validation.
#### Tool Result Content Types
Besides `TextContent`, a `CallToolResult` can return images, audio, and embedded resources — any combination of these can appear in the same result's `content` list:
```java
var syncToolSpecification = SyncToolSpecification.builder()
.tool(Tool.builder("generate-report", schema)
.description("Generates a report with mixed content")
.build())
.callHandler((exchange, request) -> {
var text = TextContent.builder("Report summary:").build();
// Image content: base64-encoded data + MIME type
var image = ImageContent.builder(base64PngData, "image/png").build();
// Audio content: base64-encoded data + MIME type
var audio = AudioContent.builder(base64WavData, "audio/wav").build();
// Embedded resource: wraps a TextResourceContents or BlobResourceContents
var resourceContents = TextResourceContents.builder("report://details", "Full details...")
.mimeType("text/plain")
.build();
var embeddedResource = EmbeddedResource.builder(resourceContents).build();
return CallToolResult.builder()
.content(List.of(text, image, audio, embeddedResource))
.isError(false)
.build();
})
.build();
```
`ImageContent.builder(data, mimeType)` and `AudioContent.builder(data, mimeType)` both take base64-encoded binary data. `EmbeddedResource.builder(resourceContents)` wraps either a `TextResourceContents` (for text data) or a `BlobResourceContents` (for base64-encoded binary data) — see [Reading Binary Resources](#reading-binary-resources) for the `BlobResourceContents` shape.
### Resource Specification
Specification of a resource with its handler function.
@ -444,6 +478,29 @@ Resources provide context to AI models by exposing data such as: File contents,
);
```
#### Reading Binary Resources
Binary resources (images, PDFs, audio, etc.) are returned as `BlobResourceContents`, which carries base64-encoded data instead of the plain `text` field used by `TextResourceContents`:
```java
var binaryResourceSpecification = new McpServerFeatures.SyncResourceSpecification(
Resource.builder("file:///logo.png", "Logo")
.description("Application logo")
.mimeType("image/png")
.build(),
(exchange, request) -> {
String base64Data = Base64.getEncoder().encodeToString(readLogoBytes());
return ReadResourceResult.builder(List.of(
BlobResourceContents.builder(request.uri(), base64Data)
.mimeType("image/png")
.build()))
.build();
}
);
```
`ReadResourceResult` accepts a list mixing `TextResourceContents` and `BlobResourceContents`, so a single resource read can return multiple representations if needed.
### Resource Subscriptions
When the `subscribe` capability is enabled, clients can subscribe to specific resources and receive targeted `notifications/resources/updated` notifications when those resources change. Only sessions that have explicitly subscribed to a given URI receive the notification — not every connected client.
@ -549,6 +606,44 @@ The prompt definition includes name (identifier for the prompt), description (pu
The handler function processes requests and returns formatted templates.
The first argument is `McpSyncServerExchange`/`McpAsyncServerExchange` for client interaction, and the second argument is a `GetPromptRequest` instance.
#### Prompts with Embedded Resources and Images
A prompt's messages can carry `EmbeddedResource` or `ImageContent` instead of plain text by passing them as the `content` argument of `PromptMessage.builder(role, content)`:
```java
// Prompt that embeds a resource's content in one of its messages
var promptWithResource = new McpServerFeatures.SyncPromptSpecification(
Prompt.builder("review-file")
.description("Reviews a file, embedding its content in the prompt")
.arguments(List.of(PromptArgument.builder("resourceUri").required(true).build()))
.build(),
(exchange, request) -> {
String resourceUri = (String) request.arguments().get("resourceUri");
var resourceContents = TextResourceContents.builder(resourceUri, loadFileContent(resourceUri))
.mimeType("text/plain")
.build();
var embeddedResource = EmbeddedResource.builder(resourceContents).build();
return GetPromptResult.builder(List.of(
PromptMessage.builder(Role.USER, embeddedResource).build(),
PromptMessage.builder(Role.USER, TextContent.builder("Please review the file above.").build()).build()))
.build();
}
);
// Prompt that embeds an image in one of its messages
var promptWithImage = new McpServerFeatures.SyncPromptSpecification(
Prompt.builder("describe-image")
.description("Asks the model to describe an embedded image")
.arguments(List.of())
.build(),
(exchange, request) -> GetPromptResult.builder(List.of(
PromptMessage.builder(Role.USER, ImageContent.builder(base64PngData, "image/png").build()).build(),
PromptMessage.builder(Role.USER, TextContent.builder("Describe the image above.").build()).build()))
.build()
);
```
### Completion Specification
Completions allow servers to provide argument autocompletion suggestions for prompts and resources:
@ -588,7 +683,42 @@ Completions allow servers to provide argument autocompletion suggestions for pro
);
```
Completions can be registered for both `PromptReference` and `ResourceReference` types.
Completions can be registered for both `PromptReference` and `ResourceReference` types. A `ResourceReference` completion suggests values for a resource template's URI parameters instead of a prompt's arguments:
=== "Sync"
```java
// Sync completion specification for a resource template argument
var syncResourceCompletionSpec = new McpServerFeatures.SyncCompletionSpecification(
new McpSchema.ResourceReference("file://{path}"), // Reference to a resource template
(exchange, request) -> {
String argName = request.argument().name();
String partial = request.argument().value();
// Return matching suggestions, e.g. matching file paths
List<String> suggestions = findMatchingPaths(partial);
return new McpSchema.CompleteResult(
new McpSchema.CompleteResult.CompleteCompletion(suggestions, suggestions.size(), false)
);
}
);
```
=== "Async"
```java
// Async completion specification for a resource template argument
var asyncResourceCompletionSpec = new McpServerFeatures.AsyncCompletionSpecification(
new McpSchema.ResourceReference("file://{path}"),
(exchange, request) -> {
String argName = request.argument().name();
String partial = request.argument().value();
List<String> suggestions = findMatchingPaths(partial);
return Mono.just(new McpSchema.CompleteResult(
new McpSchema.CompleteResult.CompleteCompletion(suggestions, suggestions.size(), false)
));
}
);
```
### Using Sampling from a Server
@ -779,6 +909,68 @@ var urlTool = SyncToolSpecification.builder()
.build();
```
#### Elicitation with Enum Values (SEP-1330)
For form elicitation, the SDK provides typed helpers to build `requestedSchema` properties that render as single-select or multi-select choices, with or without human-readable titles:
```java
// Untitled single-select: plain enum values, no separate display titles
var untitledSingle = UntitledSingleSelectEnumSchema.builder()
.enumValues("small", "medium", "large")
.build();
// Titled single-select: value/title pairs via oneOf+const
var titledSingle = TitledSingleSelectEnumSchema.builder()
.oneOf(new EnumSchemaOption("sm", "Small"),
new EnumSchemaOption("md", "Medium"),
new EnumSchemaOption("lg", "Large"))
.build();
// Untitled multi-select: an array property whose items are an enum
var untitledMulti = UntitledMultiSelectEnumSchema
.builder(UntitledMultiSelectItems.builder().enumValues("red", "green", "blue").build())
.build();
// Titled multi-select: array items with value/title pairs via anyOf+const
var titledMulti = TitledMultiSelectEnumSchema
.builder(TitledMultiSelectItems.builder()
.anyOf(new EnumSchemaOption("red", "Red"), new EnumSchemaOption("green", "Green"))
.build())
.build();
// Convert the typed schema helpers into the plain Map<String, Object> shape
// expected by ElicitRequest.builder(message, requestedSchema)
var mapper = McpJsonDefaults.getMapper();
TypeRef<Map<String, Object>> mapType = new TypeRef<>() {};
Map<String, Object> requestedSchema = Map.of("type", "object", "properties",
Map.of("size", mapper.convertValue(titledSingle, mapType),
"colors", mapper.convertValue(titledMulti, mapType)),
"required", List.of("size", "colors"));
ElicitRequest elicitRequest = ElicitRequest.builder("Choose your options", requestedSchema).build();
ElicitResult result = exchange.createElicitation(elicitRequest);
```
`LegacyTitledEnumSchema` (a value list plus a parallel `enumNames` list, built with `.enumValues(...)` and `.enumNames(...)`) is also available for clients that predate SEP-1330's `oneOf`/`anyOf` convention, but new schemas should prefer `TitledSingleSelectEnumSchema` / `TitledMultiSelectEnumSchema`.
### Pinging the Client
A server can check that a connected client is still responsive by sending a `ping` request through the exchange:
```java
var tool = SyncToolSpecification.builder()
.tool(Tool.builder("health-check", emptyJsonSchema).description("Verifies the client is reachable").build())
.callHandler((exchange, request) -> {
exchange.ping(); // blocks until the client responds, or the request times out
return CallToolResult.builder()
.content(List.of(new McpSchema.TextContent("Client is responsive")))
.build();
})
.build();
```
The async equivalent, `McpAsyncServerExchange.ping()`, returns a `Mono<Object>` that completes when the client responds. Ping requests are subject to the same `requestTimeout` configured on the server builder.
### Logging Support
The server provides structured logging capabilities that allow sending log messages to clients with different severity levels.