modelcontextprotocol/typescript-sdk

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The official TypeScript SDK for Model Context Protocol servers and clients

Stars: 13.4k
Forks: 2.2k
Open beginner issues: 25
Indexed issues: 300
Avg merge: 3d 15h
Merged PRs (30d): 4

Dominant language: TypeScript
License: No license data
Last GitHub push: Sep 16, 2026
Latest indexed: Sep 20, 2026
Contributing guide: Contributing guide
Code of conduct: Code of conduct
Beginner labels: good first issue help wanted

Beginner friendly Everything

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300 open issues indexed

`createMcpHonoApp` should support generics for Env (Bindings and Variables) Open

enhancement needs decision P3 v2

Difficulty 2/5 1-3 hours Newbie friendliness 72/100

modelcontextprotocol/typescript-sdk#1877 · 1 comment · 1 reaction · Opened Apr 11, 2026
SSE client: duplicate Authorization header when using eventSourceInit.fetch + requestInit.headers Open

bug fix proposed P2 ready for work

Difficulty 4/5 3-5 days Newbie friendliness 48/100

modelcontextprotocol/typescript-sdk#1872 · 2 comments · Opened Apr 10, 2026
prompts/get rejects omitted `arguments` when all argsSchema fields are optional; tools fix (#1404) not in 1.x Open

bug fix proposed P2 ready for work

Difficulty 4/5 3-5 days Newbie friendliness 55/100

modelcontextprotocol/typescript-sdk#1869 · 3 comments · Opened Apr 9, 2026
Add MCP_TOOL_TIMEOUT_MSEC default value only for tool calls. Open

enhancement needs decision P3

Difficulty 3/5 1-2 days Newbie friendliness 66/100

modelcontextprotocol/typescript-sdk#1863 · Opened Apr 8, 2026
mcpAuthRouter construction-time env is incompatible with request-scoped runtimes (Cloudflare Workers, Supabase Edge, etc.) Open

auth enhancement needs decision P3

Difficulty 5/5 Over a week Newbie friendliness 45/100

modelcontextprotocol/typescript-sdk#1860 · Opened Apr 8, 2026
StreamableHTTPServerTransport destroys sessions on TCP keepalive timeout (regression in 1.25+) Open

bug needs repro

Difficulty 4/5 3-5 days Newbie friendliness 45/100

modelcontextprotocol/typescript-sdk#1852 · 2 comments · Opened Apr 4, 2026
Convert tool/prompt schemas eagerly at register time instead of on tools/list Open

enhancement needs decision P3

Difficulty 4/5 3-5 days Newbie friendliness 68/100

modelcontextprotocol/typescript-sdk#1847 · Opened Apr 2, 2026
Elicit primitive schemas reject extra JSON Schema keys (pattern, format, etc.) Open

bug enhancement fix proposed P2 ready for work

Difficulty 4/5 3-5 days Newbie friendliness 56/100

modelcontextprotocol/typescript-sdk#1844 · 2 comments · Opened Apr 2, 2026
Resources: Disable listChanged capability in V1x Open

bug fix proposed P2 ready for work

Difficulty 3/5 1-2 days Newbie friendliness 48/100

modelcontextprotocol/typescript-sdk#1819 · 3 comments · Opened Mar 30, 2026
Race condition in auth() causes refresh token invalidation when rotating tokens are used Open

auth bug fix proposed P2 ready for work

Difficulty 4/5 3-5 days Newbie friendliness 68/100

modelcontextprotocol/typescript-sdk#1760 · 6 comments · 1 reaction · Opened Mar 25, 2026
Add hook or middleware for transforming tools/list responses Open

enhancement needs decision P3

Difficulty 5/5 Over a week Newbie friendliness 40/100

modelcontextprotocol/typescript-sdk#1757 · 2 comments · 1 reaction · Opened Mar 25, 2026
Evaluate OIDC nonce support Open

auth enhancement needs decision P3

modelcontextprotocol/typescript-sdk#1734 · 1 assignee · Opened Mar 23, 2026
StreamableHTTPClientTransport doesn't handle 404 per spec (no session clear + re-init) Open

bug fix proposed P2 ready for work

Difficulty 4/5 3-5 days Newbie friendliness 52/100

modelcontextprotocol/typescript-sdk#1708 · 8 comments · 2 reactions · Opened Mar 19, 2026
StreamableHTTPServerTransport has no public API to reconstruct a session-aware transport from persisted session data Open

bug enhancement P2 ready for work

modelcontextprotocol/typescript-sdk#1658 · 4 comments · 8 reactions · 1 assignee · Opened Mar 11, 2026
StreamableHTTPClientTransport cannot be restarted after close() — breaks OAuth re-authentication Open

auth bug fix proposed P2 ready for work

Difficulty 2/5 1-3 hours Newbie friendliness 72/100

modelcontextprotocol/typescript-sdk#1641 · 2 comments · Opened Mar 7, 2026
Hono Package is not under @modelcontextprotocol Open

bug potentially close

Difficulty 1/5 1-3 hours Newbie friendliness 70/100

modelcontextprotocol/typescript-sdk#1639 · 4 comments · Opened Mar 6, 2026
StreamableHTTPClientTransport should handle 404 and 406 gracefully for GET SSE stream Open

bug fix proposed P2 ready for work

Difficulty 2/5 1-3 hours Newbie friendliness 76/100

modelcontextprotocol/typescript-sdk#1635 · 3 comments · Opened Mar 5, 2026
Published 2.0.0-rc/alpha version to npmjs.com? Open

enhancement needs decision P2 v2

Difficulty 4/5 3-5 days Newbie friendliness 48/100

modelcontextprotocol/typescript-sdk#1587 · 1 comment · 5 reactions · Opened Feb 25, 2026
server.tool() silently drops inputSchema when passed plain JSON Schema objects instead of Zod schemas Open

bug potentially close

Difficulty 3/5 1-2 days Newbie friendliness 48/100

modelcontextprotocol/typescript-sdk#1585 · 5 comments · Opened Feb 25, 2026
Scope overwrite in 403 upscoping prevents progressive authorization for servers with per-operation scopes Open

auth bug fix proposed P2 ready for work

Difficulty 3/5 1-2 days Newbie friendliness 65/100

modelcontextprotocol/typescript-sdk#1582 · 1 comment · Opened Feb 24, 2026
schemaToJson() produces $ref in tool inputSchema, causing LLM failures Open

bug fix proposed P1 ready for work

Difficulty 4/5 3-5 days Newbie friendliness 55/100

modelcontextprotocol/typescript-sdk#1562 · 5 comments · 1 reaction · Opened Feb 20, 2026
consider consolidation of tooling, revise ts setup Open

enhancement needs decision P3

Difficulty 5/5 Over a week Newbie friendliness 25/100

modelcontextprotocol/typescript-sdk#1537 · Opened Feb 14, 2026
[TRACKING] non compliance with SEP-986 / tool name validation Open

help wanted improves spec compliance needs maintainer P2 question

Difficulty 5/5 Over a week Newbie friendliness 25/100

modelcontextprotocol/typescript-sdk#1512 · 8 comments · Opened Feb 10, 2026
Client received "no session ID or not initialization request" when server restart Open

bug fix proposed P2 ready for work

Difficulty 3/5 1-2 days Newbie friendliness 48/100

modelcontextprotocol/typescript-sdk#1476 · 2 comments · Opened Feb 4, 2026
Completers as a first class option in Prompts Open

enhancement needs decision P3

Difficulty 4/5 3-5 days Newbie friendliness 35/100

modelcontextprotocol/typescript-sdk#1474 · Opened Feb 3, 2026
registerToolTask handlers receive wrong arguments when inputSchema is omitted Open

bug fix proposed P2 ready for work v2

Difficulty 2/5 1-3 hours Newbie friendliness 74/100

modelcontextprotocol/typescript-sdk#1471 · 3 comments · Opened Feb 3, 2026
OAuth Token Exchange Fails with Separate Authorization Servers Open

auth bug potentially close

Difficulty 3/5 1-2 days Newbie friendliness 72/100

modelcontextprotocol/typescript-sdk#1450 · 2 comments · Opened Feb 2, 2026
Do not return and expose internal errors to the client as this is a security risk Open

bug fix proposed P2 ready for work

modelcontextprotocol/typescript-sdk#1429 · 3 comments · 1 assignee · Opened Jan 28, 2026
MCP servers deployed on AWS Lambda Function URLs stopped working after upgrading from v1.24.2 to v1.25.0+ Open

bug fix proposed P2 ready for work

Difficulty 4/5 3-5 days Newbie friendliness 48/100

modelcontextprotocol/typescript-sdk#1417 · 6 comments · Opened Jan 21, 2026
MCP 1.25 Cursor Second Connection to StreamableHTTPServerTransport Initialization Request Failed Open

bug documentation P3 potentially close question ready for work

Difficulty 4/5 3-5 days Newbie friendliness 45/100

modelcontextprotocol/typescript-sdk#1400 · 3 comments · Opened Jan 17, 2026
Task-augmented tool call errors are wrapped incorrectly, masking actual error messages Open

bug fix proposed P2 ready for work

Difficulty 3/5 1-2 days Newbie friendliness 68/100

modelcontextprotocol/typescript-sdk#1385 · 4 comments · Opened Jan 14, 2026
Consider type coercion for tool arguments Open

enhancement needs decision P3

Difficulty 5/5 Over a week Newbie friendliness 35/100

modelcontextprotocol/typescript-sdk#1361 · 1 comment · Opened Jan 6, 2026
Auth Failure Retry Handler `_hasCompletedAuthFlow` Open

auth bug enhancement needs confirmation P3

Difficulty 4/5 3-5 days Newbie friendliness 38/100

modelcontextprotocol/typescript-sdk#1317 · 1 comment · Opened Dec 19, 2025
Support RFC 8252 dynamic loopback port selection for native OAuth clients Open

auth enhancement needs decision P3

Difficulty 5/5 Over a week Newbie friendliness 35/100

modelcontextprotocol/typescript-sdk#1316 · Opened Dec 19, 2025
Tool output validation fails when outputSchema is a Zod schema other than ZodObject Open

bug fix proposed P2 ready for work

Difficulty 3/5 1-2 days Newbie friendliness 65/100

modelcontextprotocol/typescript-sdk#1308 · 8 comments · 1 reaction · Opened Dec 16, 2025
Server SDK support for signaling token expiry (401) from tool handlers Open

auth enhancement P1 ready for work

modelcontextprotocol/typescript-sdk#1294 · 3 comments · 3 reactions · 1 assignee · Opened Dec 12, 2025
Better contribution guidelines for external contributors Open

documentation enhancement P3 ready for work v2

modelcontextprotocol/typescript-sdk#1271 · 1 comment · 1 assignee · Opened Dec 8, 2025
MSW (Mock Service Worker) integration Open

enhancement needs decision P3 v2

Difficulty 4/5 3-5 days Newbie friendliness 35/100

modelcontextprotocol/typescript-sdk#1268 · 1 comment · 1 reaction · Opened Dec 8, 2025
Clear abstracted way to define experimental features Open

enhancement needs decision P3 v2

Difficulty 5/5 Over a week Newbie friendliness 25/100

modelcontextprotocol/typescript-sdk#1265 · Opened Dec 8, 2025
OpenTelemetry integration out of the box Open

enhancement P3 ready for work v2

modelcontextprotocol/typescript-sdk#1264 · 1 comment · 3 reactions · 1 assignee · Opened Dec 8, 2025
Add custom onError config points for McpError handling Open

enhancement needs decision P3 v2

Difficulty 4/5 3-5 days Newbie friendliness 35/100

modelcontextprotocol/typescript-sdk#1263 · Opened Dec 8, 2025
Inject your own logger Open

enhancement P3 ready for work v2

modelcontextprotocol/typescript-sdk#1262 · 2 assignees · Opened Dec 8, 2025
Refactor Protocol.ts to eliminate client/server conditionals Open

breaking change enhancement P3 ready for work v2

modelcontextprotocol/typescript-sdk#1260 · 1 assignee · Opened Dec 8, 2025
Class names - align with Python SDK (server, session, etc.) Open

breaking change enhancement needs decision P3 v2

Difficulty 4/5 3-5 days Newbie friendliness 35/100

modelcontextprotocol/typescript-sdk#1259 · Opened Dec 8, 2025
Type-first as opposed to Zod schema-first approach Open

breaking change enhancement needs decision P3 v2

Difficulty 5/5 Over a week Newbie friendliness 25/100

modelcontextprotocol/typescript-sdk#1253 · 1 comment · Opened Dec 8, 2025
Remove or clarify ProxyOAuthProvider Open

auth breaking change enhancement needs decision P1 v2

Difficulty 4/5 3-5 days Newbie friendliness 28/100

modelcontextprotocol/typescript-sdk#1250 · Opened Dec 8, 2025
Feature Request: Middleware support for McpServer Open

enhancement needs decision P3

Difficulty 5/5 Over a week Newbie friendliness 45/100

modelcontextprotocol/typescript-sdk#1238 · 14 comments · 2 reactions · Opened Dec 5, 2025
OAuth: Resource metadata URL lost after redirect, causing token exchange to fail Open

auth bug fix proposed P2 ready for work

Difficulty 4/5 3-5 days Newbie friendliness 45/100

modelcontextprotocol/typescript-sdk#1234 · 2 comments · Opened Dec 4, 2025
Undici instrumentation marks successful MCP requests as aborted due to premature AbortController.abort() in SSE / StreamableHTTP transports Open

enhancement help wanted P2

Difficulty 4/5 3-5 days Newbie friendliness 58/100

modelcontextprotocol/typescript-sdk#1231 · 9 comments · Opened Dec 4, 2025
SSE stream disconnected: TypeError: terminated Open

bug P2 ready for work

Difficulty 4/5 3-5 days Newbie friendliness 38/100

modelcontextprotocol/typescript-sdk#1211 · 6 comments · 1 reaction · Opened Dec 2, 2025

modelcontextprotocol/typescript-sdk

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