[WIP] Migrate to Tasks extension SDK by LucaButBoring · Pull Request #2308 · modelcontextprotocol/inspector

LucaButBoring · 2026-09-09T20:36:52Z

Following discussion on Discord, this uses the extracted Tasks implementation (see modelcontextprotocol/ext-tasks#21) to replace the implementation here.

Publishing as a draft for reference and comments; this is unusable until the actual extension SDK is merged and published to NPM (after which point I'll swap the new dependency to not be a local path). I'm keeping this PR in sync with the Tasks extension one, and once the Tasks extension one is merged, this PR can either be merged directly or used as the basis for a separate implementation.

Copilot

🟡 Changes recommended

Connection lifecycle, degraded-mode tool calls, legacy timeouts, and bounded task-input handling have unresolved regressions.

Once you've addressed the issues Copilot identified, you can request another Copilot review.

Pull request overview

Migrates Inspector task handling to the extracted ext-tasks SDK while retaining generation-neutral task APIs.

Changes:

Adds and externalizes the new Tasks SDK dependency.
Replaces custom requester/receiver task orchestration with SDK sessions.
Updates task types and refactors related test coverage.

File summaries

File	Description
`package.json`	Adds the local Tasks SDK dependency.
`package-lock.json`	Locks the local package.
`core/mcp/types.ts`	Defines neutral Inspector task types.
`core/mcp/modernTaskSchemas.ts`	Re-exports SDK schemas and identifiers.
`core/mcp/messageTrackingTransport.ts`	Simplifies raw-response consumption.
`core/mcp/inspectorClientProtocol.ts`	Updates task API types and capabilities.
`core/mcp/inspectorClientEventTarget.ts`	Migrates task event payload types.
`core/mcp/inspectorClient.ts`	Integrates requester and receiver task sessions.
`clients/web/tsup.runner.config.ts`	Externalizes the Tasks SDK.
`clients/web/src/test/integration/mcp/inspectorClient.test.ts`	Removes superseded task tests.
`clients/web/src/test/integration/mcp/inspectorClient-tasks-era.test.ts`	Removes the task input-round limit test.
`clients/web/src/test/integration/mcp/inspectorClient-modern-era.test.ts`	Accepts the SDK’s revised error wording.
`clients/web/src/test/integration/mcp/inspectorClient-coverage-backfill.test.ts`	Removes tests for deleted internals.
`clients/web/src/test/core/mcp/modernTaskSchemas.test.ts`	Removes tests for replaced schemas.
`clients/web/src/test/core/mcp/inspectorClient-raw-wire.test.ts`	Adds SDK-boundary and raw-dispatch tests.
`clients/web/src/test/core/mcp/inspectorClient-peer-handler-timing.test.ts`	Updates session lifecycle tests.
`clients/tui/tsup.config.ts`	Externalizes the Tasks SDK.
`clients/cli/tsup.config.ts`	Externalizes the Tasks SDK.

Review details

Files reviewed: 16/18 changed files
Comments generated: 4
Review effort level: Balanced

💡 Add a code-review agent skill for context-aware, tailored reviews. Learn more in the docs.

Copilot

🟡 Changes recommended

Modern task calls currently regress progress delivery, timeout behavior, and protocol-error preservation.

Once you've addressed the issues Copilot identified, you can request another Copilot review.

Review details

Files reviewed: 16/18 changed files
Comments generated: 3
Review effort level: Balanced

Copilot

🔵 Needs a closer look

The draft depends on an unpublished SDK and still has unresolved timeout and SDK-watch integration issues.

Review details

Files reviewed: 17/19 changed files
Comments generated: 2
Review effort level: Balanced

    "@modelcontextprotocol/client": "2.0.0",
    "@modelcontextprotocol/core": "2.0.0",
    "@modelcontextprotocol/ext-apps": "^1.7.4",
+    "@modelcontextprotocol/ext-tasks": "file:../mcp-ext-tasks/packages/ext-tasks",


Copilot

🔵 Needs a closer look

Core protocol lifecycle changes still contain duplicate failure events and a disconnect race, while depending on an unpublished draft SDK.

Review details

Files reviewed: 17/19 changed files
Comments generated: 1
Review effort level: Balanced

          },
+    );
+    await this.closeTaskSession();
+    this.taskSession = createTaskSessionFromClient(client, {


Copilot

🟡 Changes recommended

The new dependency breaks the SDK watch invariant, and concurrent task calls can misattribute progress events.

Once you've addressed the issues Copilot identified, you can request another Copilot review.

Review details

Suppressed comments (1)

package.json:94

Adding this scoped package makes the nightly SDK watch fail immediately: scripts/sdk-watch.mjs:250-259 rejects every root @modelcontextprotocol/* dependency absent from SDK_GROUPS, which currently contains only the TypeScript SDK packages and ext-apps. Add ext-tasks as its own upstream group and update the sdk-watch fixtures/tests so releases of this new dependency are tracked instead of breaking the workflow.

    "@modelcontextprotocol/ext-tasks": "file:../mcp-ext-tasks/packages/ext-tasks",

Files reviewed: 18/20 changed files
Comments generated: 1
Review effort level: Balanced

Copilot

🟡 Changes recommended

Auth recovery can duplicate remote tasks, SDK-watch registration is missing, and the dependency remains an unpublished local path.

Once you've addressed the issues Copilot identified, you can request another Copilot review.

Review details

Suppressed comments (1)

package.json:94

Adding another @modelcontextprotocol/* dependency without registering it in SDK_GROUPS makes the nightly SDK watch fail in assertEveryPackageWatched (scripts/sdk-watch.mjs:250-258) before it can check any releases. Add an independent ext-tasks group (it has its own repository/release cadence) and update the watcher tests as part of this dependency addition.

    "@modelcontextprotocol/ext-tasks": "file:../mcp-ext-tasks/packages/ext-tasks",

Files reviewed: 18/20 changed files
Comments generated: 1
Review effort level: Balanced

cliffhall · 2026-09-11T02:20:41Z

Hi @LucaButBoring, could you create an issue for this PR? We manage the milestones via Issues on the project board, so every PR needs an issue.

LucaButBoring · 2026-09-11T03:36:23Z

@cliffhall Opened an issue: #2316

Copilot

Copilot review overview

🔵 Needs a closer look

The migration depends on an unpublished draft SDK and leaves raw-request timeouts without wire-level cancellation.

Review effort: Balanced
Findings: 4

Open (4)

Route timeouts through transport cancellation to stop orphaned requests · New
The Task import was removed, but the legacy notifications/tasks/status handler still declares…
disconnect() can overtake either await above: it closes the current task session while this…
Adding this scoped SDK package without registering it in scripts/sdk-watch.mjs makes the nightly…

Resolved since last review (1)

Aborting a V2 raw tools/call only rejects the local promise and forwards requestSignal. That…

Copilot

Copilot review overview

🔵 Needs a closer look

Raw-request timeouts can leave remote operations running, and the draft still depends on an unpublished local package.

Review effort: Balanced
Findings: 4

Open (4)

Route timeouts through transport cancellation to stop orphaned requests
The Task import was removed, but the legacy notifications/tasks/status handler still declares…
disconnect() can overtake either await above: it closes the current task session while this…
Adding this scoped SDK package without registering it in scripts/sdk-watch.mjs makes the nightly…

Copilot

Copilot review overview

🟡 Changes recommended

Timeout cancellation, task capability routing, dependency alignment, and the unpublished local SDK remain unresolved.

Get a fresh assessment by requesting another Copilot review.

Review effort: Balanced
Findings: 5

Open (5)

Authoritative capability is unused by task refresh · New
Route timeouts through transport cancellation to stop orphaned requests
The Task import was removed, but the legacy notifications/tasks/status handler still declares…
disconnect() can overtake either await above: it closes the current task session while this…
Adding this scoped SDK package without registering it in scripts/sdk-watch.mjs makes the nightly…

Previously missed (2)

In code that hasn't changed since last review

Reuse SDK task types instead of duplicating contracts

core/mcp/types.ts:49

The extracted SDK already exposes generation-neutral TaskState and TaskView; introducing a second project-owned status union and near-copy of that view creates another contract that can drift whenever ext-tasks evolves. It also conflicts with the repository rule not to introduce InspectorTaskStatus. Reuse or alias the SDK-neutral types, adding only a narrowly documented normalized overlay if required by existing UI state.

Update SDK header to document ext-tasks

scripts/sdk-watch.mjs:104

Adding this third upstream leaves this file’s header inaccurate: lines 21–26 still state “Two upstreams, not one” and describe only TypeScript SDK plus ext-apps. Update that design rationale to include ext-tasks so the source documentation matches SDK_GROUPS.

Copilot

Copilot review overview

🔵 Needs a closer look

The migration depends on an unpublished draft SDK and still drops request context during task recovery.

Review effort: Balanced
Findings: 4 · 1

Open (5)

Authoritative capability is unused by task refresh
The Task import was removed, but the legacy notifications/tasks/status handler still declares…
disconnect() can overtake either await above: it closes the current task session while this…
Adding this scoped SDK package without registering it in scripts/sdk-watch.mjs makes the nightly…
Update module documentation for all three upstream groups · New

Resolved since last review (1)

Route timeouts through transport cancellation to stop orphaned requests

Copilot

Copilot review overview

🔵 Needs a closer look

The cross-cutting protocol migration still depends on an unpublished local package and its upstream SDK pull request remains a blocked draft.

Review effort: Balanced
Findings: 4

Open (4)

Authoritative capability is unused by task refresh
The Task import was removed, but the legacy notifications/tasks/status handler still declares…
disconnect() can overtake either await above: it closes the current task session while this…
Adding this scoped SDK package without registering it in scripts/sdk-watch.mjs makes the nightly…

Resolved since last review (1)

Update module documentation for all three upstream groups

Previously missed (1)

In code that hasn't changed since last review

Test known-handles branch re-polls seeded task

core/mcp/state/managedRequestorTasksState.ts:155

The new known-handles branch is only tested with an empty store, so the test would still pass if this path returned immediately and never called getRequestorTask. Seed one known task before switching the fake to known-handles, then assert refresh re-polls that ID and still avoids listRequestorTasks; this is the behavior this branch is intended to protect.

Copilot

Copilot review overview

🔵 Needs a closer look

It rewires task execution and lifecycle behavior around an unpublished draft SDK and still uses a non-portable local dependency.

Review effort: Balanced
Findings: 4

Open (4)

Authoritative capability is unused by task refresh
The Task import was removed, but the legacy notifications/tasks/status handler still declares…
disconnect() can overtake either await above: it closes the current task session while this…
Adding this scoped SDK package without registering it in scripts/sdk-watch.mjs makes the nightly…

Previously missed (1)

In code that hasn't changed since last review

Update security rationale to document all three upstreams

AGENTS.md:132

Adding the third upstream leaves the security rationale stale: AGENTS.md:165 and .github/workflows/sdk-watch.yml still say the analysis reads “both upstreams” and enumerate only TypeScript SDK and ext-apps. Update both to include ext-tasks so the documented first-party-input threat model matches what the workflow now analyzes.

Copilot

Copilot review overview

🟡 Changes recommended

The dependency currently references an unavailable sibling checkout, preventing clean installs and publication.

Get a fresh assessment by requesting another Copilot review.

Review effort: Balanced
Findings: 5

Open (5)

Use published ext-tasks dependency instead of sibling path · New
Authoritative capability is unused by task refresh
The Task import was removed, but the legacy notifications/tasks/status handler still declares…
disconnect() can overtake either await above: it closes the current task session while this…
Adding this scoped SDK package without registering it in scripts/sdk-watch.mjs makes the nightly…

    "@modelcontextprotocol/client": "2.0.0",
    "@modelcontextprotocol/core": "2.0.0",
    "@modelcontextprotocol/ext-apps": "^1.7.4",
+    "@modelcontextprotocol/ext-tasks": "file:../mcp-ext-tasks/packages/ext-tasks",


Copilot

Copilot review overview

🟡 Changes recommended

Raw progress handling and task recovery currently contain correctness regressions, while the dependency remains unpublished.

Get a fresh assessment by requesting another Copilot review.

Review effort: Balanced
Findings: 4 · 2

Open (6)

Use published ext-tasks dependency instead of sibling path
The Task import was removed, but the legacy notifications/tasks/status handler still declares…
disconnect() can overtake either await above: it closes the current task session while this…
Adding this scoped SDK package without registering it in scripts/sdk-watch.mjs makes the nightly…
Guard notification params before reading progressToken · New
Preserve headers and timeout when resuming tasks · New

Resolved since last review (1)

Authoritative capability is unused by task refresh

+    if (message.method !== "notifications/progress") return;
+    const params = message.params as Progress & {
+      progressToken?: ProgressToken;
+    };
+    const progressToken = params.progressToken;
+    if (progressToken === undefined) return;


+        ? await session.resumeTask<CallToolResult>(recovery.reference, {
+            resultCodec: taskToolResultCodec,
+            declaration: toolDeclarationFromMcpTool(tool),
+            signal,
+          })


Copilot AI balanced review requested due to automatic review settings September 9, 2026 20:36

LucaButBoring mentioned this pull request Sep 9, 2026

Introduce extension SDK for TS modelcontextprotocol/ext-tasks#21

Merged

9 tasks

Copilot started reviewing on behalf of LucaButBoring September 9, 2026 20:37 View session

Copilot AI reviewed Sep 9, 2026

View reviewed changes

Comment thread core/mcp/inspectorClient.ts

Comment thread core/mcp/inspectorClient.ts

Comment thread core/mcp/inspectorClient.ts Outdated

Comment thread core/mcp/inspectorClient.ts Outdated

Copilot AI review requested due to automatic review settings September 10, 2026 01:07

Copilot started reviewing on behalf of LucaButBoring September 10, 2026 01:08 View session

Copilot AI reviewed Sep 10, 2026

View reviewed changes

Comment thread core/mcp/inspectorClient.ts Outdated

Comment thread core/mcp/inspectorClient.ts Outdated

Comment thread core/mcp/inspectorClient.ts

Copilot AI review requested due to automatic review settings September 10, 2026 18:39

Copilot started reviewing on behalf of LucaButBoring September 10, 2026 18:40 View session

Copilot AI reviewed Sep 10, 2026

View reviewed changes

Comment thread package.json

"@modelcontextprotocol/client": "2.0.0",

"@modelcontextprotocol/core": "2.0.0",

"@modelcontextprotocol/ext-apps": "^1.7.4",

"@modelcontextprotocol/ext-tasks": "file:../mcp-ext-tasks/packages/ext-tasks",

Comment thread core/mcp/inspectorClient.ts

Copilot AI review requested due to automatic review settings September 10, 2026 21:25

Copilot started reviewing on behalf of LucaButBoring September 10, 2026 21:25 View session

Copilot AI reviewed Sep 10, 2026

View reviewed changes

Comment thread core/mcp/inspectorClient.ts

},

);

await this.closeTaskSession();

this.taskSession = createTaskSessionFromClient(client, {

LucaButBoring added 6 commits September 10, 2026 14:40

feat: draft MCP Tasks extension SDK migration

feced07

chore: update task tool calls

88cea2b

fix: address Copilot comments

cd8dea1

fix: address Copilot comments

8d1fdc7

fix: address Copilot comments

3a9cbba

fix: address Copilot comments

790b421

Copilot AI review requested due to automatic review settings September 10, 2026 23:46

LucaButBoring force-pushed the feat/ext-tasks branch from 6a69c33 to 790b421 Compare September 10, 2026 23:46

Copilot started reviewing on behalf of LucaButBoring September 10, 2026 23:47 View session

Copilot AI reviewed Sep 10, 2026

View reviewed changes

Comment thread core/mcp/inspectorClient.ts

fix: address Copilot comments

7ae45f6

Copilot AI review requested due to automatic review settings September 11, 2026 00:40

Copilot started reviewing on behalf of LucaButBoring September 11, 2026 00:41 View session

Copilot AI reviewed Sep 11, 2026

View reviewed changes

Comment thread core/mcp/inspectorClient.ts

LucaButBoring mentioned this pull request Sep 11, 2026

Extract Tasks logic to dedicated wrapper SDK #2316

Open

2 tasks

fix: address Copilot concerns

9b48ec1

Copilot AI review requested due to automatic review settings September 22, 2026 06:52

Copilot started reviewing on behalf of LucaButBoring September 22, 2026 06:53 View session

Copilot AI reviewed Sep 22, 2026

View reviewed changes

Comment thread core/mcp/inspectorClient.ts

fix: address Copilot concerns

53bafda

Copilot AI review requested due to automatic review settings September 22, 2026 17:50

Copilot started reviewing on behalf of LucaButBoring September 22, 2026 17:50 View session

Copilot AI reviewed Sep 22, 2026

View reviewed changes

Copilot AI review requested due to automatic review settings September 22, 2026 17:54

Copilot started reviewing on behalf of LucaButBoring September 22, 2026 17:54 View session

Copilot AI reviewed Sep 22, 2026

View reviewed changes

Comment thread core/mcp/inspectorClientProtocol.ts Outdated

fix: address Copilot concerns

e34032c

Copilot AI review requested due to automatic review settings September 22, 2026 21:44

Copilot started reviewing on behalf of LucaButBoring September 22, 2026 21:44 View session

Copilot AI reviewed Sep 22, 2026

View reviewed changes

Comment thread scripts/sdk-watch.mjs

fix: address Copilot concerns

9764262

Copilot AI review requested due to automatic review settings September 23, 2026 01:26

Copilot started reviewing on behalf of LucaButBoring September 23, 2026 01:27 View session

Copilot AI reviewed Sep 23, 2026

View reviewed changes

fix: address Copilot concerns

85ba9a3

Copilot AI review requested due to automatic review settings September 23, 2026 02:17

Copilot started reviewing on behalf of LucaButBoring September 23, 2026 02:17 View session

Copilot AI reviewed Sep 23, 2026

View reviewed changes

fix: address Copilot concerns

7b3e848

Copilot AI review requested due to automatic review settings September 23, 2026 02:53

Copilot started reviewing on behalf of LucaButBoring September 23, 2026 02:54 View session

Copilot AI reviewed Sep 23, 2026

View reviewed changes

Comment thread package.json

"@modelcontextprotocol/client": "2.0.0",

"@modelcontextprotocol/core": "2.0.0",

"@modelcontextprotocol/ext-apps": "^1.7.4",

"@modelcontextprotocol/ext-tasks": "file:../mcp-ext-tasks/packages/ext-tasks",

LucaButBoring requested a balanced review from Copilot September 23, 2026 12:37

Copilot started reviewing on behalf of LucaButBoring September 23, 2026 12:38 View session

Copilot AI reviewed Sep 23, 2026

View reviewed changes

Conversation

LucaButBoring commented Sep 9, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

Copilot AI left a comment

Choose a reason for hiding this comment

🟡 Changes recommended

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Copilot AI left a comment

Choose a reason for hiding this comment

🟡 Changes recommended

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Copilot AI left a comment

Choose a reason for hiding this comment

🔵 Needs a closer look

Uh oh!

Uh oh!

Copilot AI left a comment

Choose a reason for hiding this comment

🔵 Needs a closer look

Uh oh!

Copilot AI left a comment

Choose a reason for hiding this comment

🟡 Changes recommended

Suppressed comments (1)

Uh oh!

Uh oh!

Copilot AI left a comment

Choose a reason for hiding this comment

🟡 Changes recommended

Suppressed comments (1)

Uh oh!

Uh oh!

cliffhall commented Sep 11, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

LucaButBoring commented Sep 11, 2026

Uh oh!

Copilot AI left a comment

Choose a reason for hiding this comment

Copilot review overview

🔵 Needs a closer look

Uh oh!

Uh oh!

Copilot AI left a comment

Choose a reason for hiding this comment

Copilot review overview

🔵 Needs a closer look

Uh oh!

Copilot AI left a comment

Choose a reason for hiding this comment

Copilot review overview

🟡 Changes recommended

Uh oh!

Uh oh!

Copilot AI left a comment

Choose a reason for hiding this comment

Copilot review overview

🔵 Needs a closer look

Uh oh!

Uh oh!

Copilot AI left a comment

Choose a reason for hiding this comment

Copilot review overview

🔵 Needs a closer look

Uh oh!

Copilot AI left a comment

Choose a reason for hiding this comment

Copilot review overview

🔵 Needs a closer look

Uh oh!

Copilot AI left a comment

Choose a reason for hiding this comment

LucaButBoring commented Sep 9, 2026 •

edited

Loading

cliffhall commented Sep 11, 2026 •

edited

Loading