modelcontextprotocol/go-sdk

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The official Go SDK for Model Context Protocol servers and clients. Maintained in collaboration with Google.

Stars: 5.1k
Forks: 543
Open beginner issues: 0
Indexed issues: 57
Avg merge: 1d 17h
Merged PRs (30d): 37

Dominant language: Go
License: No license data
Last GitHub push: Sep 18, 2026
Latest indexed: Sep 20, 2026
Contributing guide: Contributing guide
Code of conduct: Code of conduct
Beginner labels: help wanted

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57 open issues indexed

mcp: keepalive logs an ordinary client disconnect at Error, drowning real failures Open

Difficulty 2/5 1-3 hours Newbie friendliness 78/100

modelcontextprotocol/go-sdk#1281 · Opened Sep 19, 2026
mcp: the negotiated protocol version is recorded on one path of four, so stdio accepts batches a SEP-2575 session forbids Open

Difficulty 3/5 1-2 days Newbie friendliness 64/100

modelcontextprotocol/go-sdk#1272 · Opened Sep 15, 2026
mcp: a resource update cannot be delivered to one session, and the caller's context never reaches the sending middleware Open

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

modelcontextprotocol/go-sdk#1265 · Opened Sep 13, 2026
proposal: mcp: expose the JSON-RPC request id to receiving middleware and handlers Open

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

modelcontextprotocol/go-sdk#1264 · Opened Sep 13, 2026
mcp: a server cannot send the notifications/cancelled that 2026-07-28 requires when it tears down a subscriptions/listen stream Open

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

modelcontextprotocol/go-sdk#1263 · Opened Sep 13, 2026
mcp: an SSE response keeps http.Server.WriteTimeout armed, so a long-lived stream dies before its first notification Open

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

modelcontextprotocol/go-sdk#1262 · 2 comments · Opened Sep 13, 2026
A cancelled request is still answered Open

Difficulty 4/5 3-5 days Newbie friendliness 25/100

modelcontextprotocol/go-sdk#1259 · Opened Sep 13, 2026
mcp: the declared protocol version, not the negotiated one, decides what a session is served Open

Difficulty 4/5 3-5 days Newbie friendliness 25/100

modelcontextprotocol/go-sdk#1258 · Opened Sep 13, 2026
Index: nine findings from one audit of a large MCP server against the specification Open

Difficulty 5/5 Over a week Newbie friendliness 15/100

modelcontextprotocol/go-sdk#1257 · 1 reaction · Opened Sep 13, 2026
Streamable HTTP: an x-mcp-header in a non-reachable schema position (items, oneOf, $ref, ...) is silently accepted instead of rejected Open

P3

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

modelcontextprotocol/go-sdk#1250 · 1 comment · Opened Sep 9, 2026
proposal: auth: support SEP-2350 request-time scope challenges Open

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

modelcontextprotocol/go-sdk#1248 · Opened Sep 7, 2026
A response is still written for a request after notifications/cancelled Open

P2

Difficulty 3/5 1-2 days Newbie friendliness 78/100

modelcontextprotocol/go-sdk#1235 · 1 comment · Opened Sep 3, 2026
mcp: add StreamableHTTPOptions.StreamKeepAlive — the SSE keep-alive comment the 2026-07-28 spec encourages for subscriptions/listen Open

P2

Difficulty 4/5 3-5 days Newbie friendliness 65/100

modelcontextprotocol/go-sdk#1229 · Opened Sep 2, 2026
mcp: ResourceUpdated notifies subscribers serially, so one stalled stream write starves every other subscriber of the URI Open

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

modelcontextprotocol/go-sdk#1227 · 1 comment · Opened Sep 2, 2026
mcp: a malformed JSON frame terminates the stdio session Open

Difficulty 3/5 1-2 days Newbie friendliness 35/100

modelcontextprotocol/go-sdk#1209 · Opened Aug 29, 2026
Session-lifecycle bookkeeping logs at info, spamming multiple log lines per request on stateless streamable HTTP Open

P3

Difficulty 2/5 1-3 hours Newbie friendliness 75/100

modelcontextprotocol/go-sdk#1204 · Opened Aug 28, 2026
mcp: typed tool arguments lose precision for large int64 values Open

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

modelcontextprotocol/go-sdk#1201 · 1 comment · Opened Aug 27, 2026
sse: Close does not drain incoming; Read can deliver stale messages after Close and POST can return false 202 Open

P3

Difficulty 3/5 1-2 days Newbie friendliness 78/100

modelcontextprotocol/go-sdk#1191 · Opened Aug 23, 2026
streamable client: Connect blocks far past its context deadline against an unresponsive server (detached-context cleanup) Open

needs investigation

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

modelcontextprotocol/go-sdk#1189 · 11 comments · Opened Aug 20, 2026
Dual-era servers serve modern Tool schemas unchanged to legacy clients Open

P2

Difficulty 5/5 Over a week Newbie friendliness 38/100

modelcontextprotocol/go-sdk#1188 · 2 comments · Opened Aug 20, 2026
stdio: a server that exits on the server/discover probe leaves Client.Connect no way to reach the documented initialize fallback Open

P3

Difficulty 4/5 3-5 days Newbie friendliness 42/100

modelcontextprotocol/go-sdk#1177 · 1 comment · Opened Aug 16, 2026
ClientSession.Subscribe can silently succeed while the session is closing Open

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

modelcontextprotocol/go-sdk#1171 · Opened Aug 13, 2026
mcp: Client.Connect succeeds after subscriptions/listen is rejected Open

P3

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

modelcontextprotocol/go-sdk#1169 · 1 comment · Opened Aug 13, 2026
initialize sends no Mcp-Protocol-Version of its own, so the header can contradict params.protocolVersion Open

P3

Difficulty 3/5 1-2 days Newbie friendliness 35/100

modelcontextprotocol/go-sdk#1164 · Opened Aug 13, 2026
Streamable HTTP: POST response writes nothing until the request completes, so long tool calls look like a dead connection Open

P2

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

modelcontextprotocol/go-sdk#1155 · 1 comment · Opened Aug 9, 2026
jsonrpc2.Connection.processResult silently discards write errors for late responses, giving no signal when a response can't be delivered Open

P2

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

modelcontextprotocol/go-sdk#1147 · 4 comments · Opened Aug 5, 2026
proposal: client DPoP support (SEP-1932 baseline, no nonce) Open

P3

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

modelcontextprotocol/go-sdk#1139 · 3 comments · Opened Aug 4, 2026
RequireBearerToken omits RFC 6750 error code, so the SDK's own step-up flow never triggers Open

P2

Difficulty 3/5 1-2 days Newbie friendliness 38/100

modelcontextprotocol/go-sdk#1134 · Opened Aug 2, 2026
auth: DCR registration omits scopes, causing invalid_scope on strict auth servers Open

P2

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

modelcontextprotocol/go-sdk#1102 · 1 reaction · Opened Jul 17, 2026
server/discover is not customizable or host-invokable (no DiscoverHandler option / session Discover API) Open

P3

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

modelcontextprotocol/go-sdk#1092 · 1 comment · Opened Jul 15, 2026
mcp: expose parsed streamable HTTP request summary hook Open

P3

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

modelcontextprotocol/go-sdk#1076 · 7 comments · Opened Jul 13, 2026
stdio: responses to already-received requests are dropped when stdin EOF arrives first (one-shot pipes get no output) Open

P2

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

modelcontextprotocol/go-sdk#1061 · Opened Jul 9, 2026
(possible) 2026-07-28 spec violation: mcp-session-id used in client requests with 2026-07-28 Open

P3

Difficulty 3/5 1-2 days Newbie friendliness 55/100

modelcontextprotocol/go-sdk#1028 · 1 comment · Opened Jun 26, 2026
Proposal: dynamic/lazy resources/list (and directory-read) backing for gateway/proxy and template-served catalogs Open

P3

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

modelcontextprotocol/go-sdk#998 · 5 comments · Opened Jun 9, 2026
Expose max JSON-RPC frame/message size for stdio transports Open

needs confirmation

Difficulty 5/5 Over a week Newbie friendliness 38/100

modelcontextprotocol/go-sdk#984 · Opened May 31, 2026
Remove support for batching on streamable connection Open

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

modelcontextprotocol/go-sdk#911 · Opened Apr 27, 2026
Allow configuring additionalProperties on generated tool schemas Open

blocked

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

modelcontextprotocol/go-sdk#892 · 3 comments · Opened Apr 10, 2026
Potential race condition in (*mcp.ClientSession).Close() Open

needs investigation P2

Difficulty 3/5 1-2 days Newbie friendliness 75/100

modelcontextprotocol/go-sdk#855 · 3 comments · 1 reaction · Opened Mar 24, 2026
Support Schema Cycles Open

blocked

Difficulty 4/5 3-5 days Newbie friendliness 42/100

modelcontextprotocol/go-sdk#749 · 1 comment · 3 reactions · Opened Jan 12, 2026
Expose generic `SendNotification` on `ServerSession` for custom protocol extensions Open

needs investigation

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

modelcontextprotocol/go-sdk#745 · 13 comments · 1 reaction · Opened Jan 6, 2026
Proposal: Strong Typing for CallTool Open

needs community feedback

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

modelcontextprotocol/go-sdk#735 · 5 comments · Opened Dec 24, 2025
Add examples to modelcontextprotocol.io Open

external help wanted ready for work

modelcontextprotocol/go-sdk#720 · 14 comments · 1 assignee · Opened Dec 12, 2025
Fix handling for nil pointers given user-provided output schema Open

breaking change P3 v2

Difficulty 3/5 1-2 days Newbie friendliness 35/100

modelcontextprotocol/go-sdk#691 · 3 comments · 2 reactions · Opened Dec 5, 2025
SSEClientTransport drops path prefix when endpoint URL is not on the HTTP root (similar to python-sdk#563) Open

needs investigation

Difficulty 3/5 1-2 days Newbie friendliness 50/100

modelcontextprotocol/go-sdk#687 · 3 comments · Opened Dec 5, 2025
StreamableClientTransport: Connection poisoned by transient errors Open

needs investigation

modelcontextprotocol/go-sdk#683 · 6 comments · 11 reactions · 1 assignee · Opened Dec 4, 2025
Proposal: support for sending `tools/list_changed` notifications manually Open

needs investigation

Difficulty 3/5 1-2 days Newbie friendliness 55/100

modelcontextprotocol/go-sdk#666 · 17 comments · 2 reactions · Opened Nov 27, 2025
Proposal: allow `mcp.streamableClientConn` to listen to SSE stream without using `mcp.Client` Open

needs investigation

Difficulty 4/5 3-5 days Newbie friendliness 62/100

modelcontextprotocol/go-sdk#657 · 8 comments · Opened Nov 25, 2025
Proposal: provide a Server.SetTools method Open

needs community feedback

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

modelcontextprotocol/go-sdk#639 · 1 comment · Opened Nov 14, 2025
SEP-1686 (experimental): Implement Tasks Open

ready for work

Difficulty 5/5 Over a week Newbie friendliness 30/100

modelcontextprotocol/go-sdk#626 · 9 comments · 3 reactions · Opened Nov 7, 2025
Proposal: Provide better error handling for HTTP errors when using a Streamable Client Open

needs community feedback

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

modelcontextprotocol/go-sdk#579 · 10 comments · 1 reaction · Opened Oct 14, 2025

modelcontextprotocol/go-sdk

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