mcp: HTTP Header Standardization for x-mcp-header by guglielmo-san · Pull Request #915 · modelcontextprotocol/go-sdk

guglielmo-san · 2026-04-29T17:26:19Z

Description

Implements SEP-2243 (HTTP Header Standardization) for x-mcp-param custom header.

Fixes#905

…ard request headers

…treamableClientConn

…rs for tool calls

… requests

…e comparison for parameter validation

…ccessor

…es and add structural validation

…ttp_standardization_2 # Conflicts: # mcp/streamable.go # mcp/streamable_client_test.go # mcp/streamable_headers.go # mcp/streamable_headers_test.go # mcp/streamable_test.go

…ernal JSON unmarshaling

…ors in ClientSession

…treamable_test.go

…_http_standardization_2' into guglielmoc/SEP-2243_http_standardization_2

maciej-kisiel

Also some additional comments from AI review :)

…er validation to support JSON schema annotations

…eaders

…assignment

…nd unify primitive type string conversion

…panic on invalid header annotations

…ccess status for type validation

Co-authored-by: Maciej Kisiel <mkisiel@google.com>

…maps

guglielmo-san · 2026-04-29T17:26:19Z

Description

Implements SEP-2243 (HTTP Header Standardization) for x-mcp-param custom header.

Fixes#905

…ard request headers

…treamableClientConn

…rs for tool calls

… requests

…e comparison for parameter validation

…ccessor

…es and add structural validation

…ttp_standardization_2 # Conflicts: # mcp/streamable.go # mcp/streamable_client_test.go # mcp/streamable_headers.go # mcp/streamable_headers_test.go # mcp/streamable_test.go

…ernal JSON unmarshaling

…ors in ClientSession

…treamable_test.go

…_http_standardization_2' into guglielmoc/SEP-2243_http_standardization_2

maciej-kisiel

Also some additional comments from AI review :)

…er validation to support JSON schema annotations

…eaders

…assignment

…nd unify primitive type string conversion

…panic on invalid header annotations

…ccess status for type validation

Co-authored-by: Maciej Kisiel <mkisiel@google.com>

…maps

guglielmo-san · 2026-04-29T17:26:19Z

Description

Implements SEP-2243 (HTTP Header Standardization) for x-mcp-param custom header.

Fixes#905

…ard request headers

…treamableClientConn

…rs for tool calls

… requests

…e comparison for parameter validation

…ccessor

…es and add structural validation

…ttp_standardization_2 # Conflicts: # mcp/streamable.go # mcp/streamable_client_test.go # mcp/streamable_headers.go # mcp/streamable_headers_test.go # mcp/streamable_test.go

…ernal JSON unmarshaling

…ors in ClientSession

…treamable_test.go

…_http_standardization_2' into guglielmoc/SEP-2243_http_standardization_2

maciej-kisiel

Also some additional comments from AI review :)

…er validation to support JSON schema annotations

…eaders

…assignment

…nd unify primitive type string conversion

…panic on invalid header annotations

…ccess status for type validation

Co-authored-by: Maciej Kisiel <mkisiel@google.com>

…maps

guglielmo-san · 2026-04-29T17:26:19Z

Description

Implements SEP-2243 (HTTP Header Standardization) for x-mcp-param custom header.

Fixes#905

…ard request headers

…treamableClientConn

…rs for tool calls

… requests

…e comparison for parameter validation

…ccessor

…es and add structural validation

…ttp_standardization_2 # Conflicts: # mcp/streamable.go # mcp/streamable_client_test.go # mcp/streamable_headers.go # mcp/streamable_headers_test.go # mcp/streamable_test.go

…ernal JSON unmarshaling

…ors in ClientSession

…treamable_test.go

…_http_standardization_2' into guglielmoc/SEP-2243_http_standardization_2

maciej-kisiel

Also some additional comments from AI review :)

…er validation to support JSON schema annotations

…eaders

…assignment

…nd unify primitive type string conversion

…panic on invalid header annotations

…ccess status for type validation

Co-authored-by: Maciej Kisiel <mkisiel@google.com>

…maps

guglielmo-san · 2026-04-29T17:26:19Z

Description

Implements SEP-2243 (HTTP Header Standardization) for x-mcp-param custom header.

Fixes#905

…ard request headers

…treamableClientConn

…rs for tool calls

… requests

…e comparison for parameter validation

…ccessor

…es and add structural validation

…ttp_standardization_2 # Conflicts: # mcp/streamable.go # mcp/streamable_client_test.go # mcp/streamable_headers.go # mcp/streamable_headers_test.go # mcp/streamable_test.go

…ernal JSON unmarshaling

…ors in ClientSession

…treamable_test.go

…_http_standardization_2' into guglielmoc/SEP-2243_http_standardization_2

maciej-kisiel

Also some additional comments from AI review :)

…er validation to support JSON schema annotations

…eaders

…assignment

…nd unify primitive type string conversion

…panic on invalid header annotations

…ccess status for type validation

Co-authored-by: Maciej Kisiel <mkisiel@google.com>

…maps

guglielmo-san · 2026-04-29T17:26:19Z

Description

Implements SEP-2243 (HTTP Header Standardization) for x-mcp-param custom header.

Fixes#905

…ard request headers

…treamableClientConn

…rs for tool calls

… requests

…e comparison for parameter validation

…ccessor

…es and add structural validation

…ttp_standardization_2 # Conflicts: # mcp/streamable.go # mcp/streamable_client_test.go # mcp/streamable_headers.go # mcp/streamable_headers_test.go # mcp/streamable_test.go

…ernal JSON unmarshaling

…ors in ClientSession

…treamable_test.go

…_http_standardization_2' into guglielmoc/SEP-2243_http_standardization_2

maciej-kisiel

Also some additional comments from AI review :)

…er validation to support JSON schema annotations

…eaders

…assignment

…nd unify primitive type string conversion

…panic on invalid header annotations

…ccess status for type validation

Co-authored-by: Maciej Kisiel <mkisiel@google.com>

…maps

guglielmo-san · 2026-04-29T17:26:19Z

Description

Implements SEP-2243 (HTTP Header Standardization) for x-mcp-param custom header.

Fixes#905

…ard request headers

…treamableClientConn

…rs for tool calls

… requests

…e comparison for parameter validation

…ccessor

…es and add structural validation

…ttp_standardization_2 # Conflicts: # mcp/streamable.go # mcp/streamable_client_test.go # mcp/streamable_headers.go # mcp/streamable_headers_test.go # mcp/streamable_test.go

…ernal JSON unmarshaling

…ors in ClientSession

…treamable_test.go

…_http_standardization_2' into guglielmoc/SEP-2243_http_standardization_2

maciej-kisiel

Also some additional comments from AI review :)

…er validation to support JSON schema annotations

…eaders

…assignment

…nd unify primitive type string conversion

…panic on invalid header annotations

…ccess status for type validation

Co-authored-by: Maciej Kisiel <mkisiel@google.com>

…maps

guglielmo-san · 2026-04-29T17:26:19Z

Description

Implements SEP-2243 (HTTP Header Standardization) for x-mcp-param custom header.

Fixes#905

…ard request headers

…treamableClientConn

…rs for tool calls

… requests

…e comparison for parameter validation

…ccessor

…es and add structural validation

…ttp_standardization_2 # Conflicts: # mcp/streamable.go # mcp/streamable_client_test.go # mcp/streamable_headers.go # mcp/streamable_headers_test.go # mcp/streamable_test.go

…ernal JSON unmarshaling

…ors in ClientSession

…treamable_test.go

…_http_standardization_2' into guglielmoc/SEP-2243_http_standardization_2

maciej-kisiel

Also some additional comments from AI review :)

…er validation to support JSON schema annotations

…eaders

…assignment

…nd unify primitive type string conversion

…panic on invalid header annotations

…ccess status for type validation

Co-authored-by: Maciej Kisiel <mkisiel@google.com>

…maps

guglielmo-san added 19 commits April 24, 2026 14:08

refactor: centralize MCP headers and add support for validating stand…
f00d0f4
…ard request headers

fix
d00288d

formatter
57659c0

Merge branch 'main' into guglielmoc/SEP-2243_http_standardization
017e0fc

fix after merge
604f2d4

refactor: decouple standard header population from setMCPHeaders in s…
7df5ab6
…treamableClientConn

feat: implement SEP-2243 header encoding and support Mcp-Param- heade…
9de3bec
…rs for tool calls

feat: implement validation for tool-specific parameter headers in MCP…
f429bc5
… requests

feat: implement base64 header decoding and standardize primitive valu…
ad17562
…e comparison for parameter validation

refactor: simplify MCP header logic and remove redundant tool cache a…
a4e1e23
…ccessor

refactor: prohibit x-mcp-header annotations on nested object properti…
aeada36
…es and add structural validation

refactor: rename mcp_http_headers to streamable_headers
b223143

Merge remote-tracking branch 'origin/main' into guglielmoc/SEP-2243_h…
005d33d
…ttp_standardization_2 # Conflicts: # mcp/streamable.go # mcp/streamable_client_test.go # mcp/streamable_headers.go # mcp/streamable_headers_test.go # mcp/streamable_test.go

feat: enable MCP parameter headers and add validation tests using int…
24cc607
…ernal JSON unmarshaling

fix: add mutex protection to toolCache and provide thread-safe access…
9dd6907
…ors in ClientSession

test: remove assertion for non-annotated query parameter headers in s…
8d4e94d
…treamable_test.go

Merge branch 'main' into guglielmoc/SEP-2243_http_standardization_2
d8c5a76

refactor: remove redundant blank line in streamable_headers.go
e754ff7

Merge remote-tracking branch 'refs/remotes/origin/guglielmoc/SEP-2243…
87093cb
…_http_standardization_2' into guglielmoc/SEP-2243_http_standardization_2

guglielmo-san marked this pull request as ready for review April 30, 2026 13:27

guglielmo-san requested a review from maciej-kisiel April 30, 2026 13:28

guglielmo-san added 3 commits April 30, 2026 13:51

merge tests
04652ee

minor fix
d7ef2c1

Merge branch 'main' into guglielmoc/SEP-2243_http_standardization_2
c218557

guglielmo-san changed the title ~~feat: HTTP Header Standardization for x-mcp-header~~mcp: HTTP Header Standardization for x-mcp-headerMay 5, 2026

maciej-kisiel reviewed May 5, 2026
View reviewed changes

maciej-kisiel mentioned this pull request May 5, 2026
SEP-2243 HTTP Standardization modelcontextprotocol/modelcontextprotocol#2243
Merged
9 tasks

maciej-kisiel reviewed May 5, 2026
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Comment threadmcp/streamable_headers.go Outdated
Comment threadmcp/client.go

guglielmo-san added 2 commits May 5, 2026 15:06

refactor: inline header encoding logic and update tool parameter head…
e83292b
…er validation to support JSON schema annotations

refactor: remove unused mcpHeaderExtension constant from streamable h…
9bdd1df
…eaders

guglielmo-san requested a review from maciej-kisiel May 5, 2026 15:19

maciej-kisiel reviewed May 6, 2026
View reviewed changes

Comment threadmcp/streamable.go Outdated

guglielmo-san added 2 commits May 6, 2026 12:00

refactor: expose ToolLookup method on Server and simplify connection …
2faa9a9
…assignment

Merge branch 'main' into guglielmoc/SEP-2243_http_standardization_2
8d68d57

guglielmo-san requested a review from maciej-kisiel May 6, 2026 12:00

maciej-kisiel reviewed May 6, 2026
View reviewed changes

guglielmo-san added 3 commits May 6, 2026 14:42

refactor: update tool lookup mechanism to include header validation a…
bc2124a
…nd unify primitive type string conversion

refactor: simplify encodeHeaderValue interface and update AddTool to …
aefecc0
…panic on invalid header annotations

refactor: update encodeHeaderValue and primitiveToString to return su…
9d69fe1
…ccess status for type validation

guglielmo-san requested a review from maciej-kisiel May 6, 2026 14:59

Merge branch 'main' into guglielmoc/SEP-2243_http_standardization_2
7fe797d

maciej-kisiel reviewed May 7, 2026
View reviewed changes

Comment threadmcp/streamable_headers.go
Comment threadmcp/streamable_headers_test.go Outdated

guglielmo-sanand others added 3 commits May 7, 2026 11:47

Update mcp/streamable_headers.go
f51b46c
Co-authored-by: Maciej Kisiel <mkisiel@google.com>

Merge branch 'main' into guglielmoc/SEP-2243_http_standardization_2
0544a2c

test: update streamable headers tests to expect nil instead of empty …
40d050b
…maps

guglielmo-san requested a review from maciej-kisiel May 8, 2026 10:37

maciej-kisiel approved these changes May 8, 2026
View reviewed changes

maciej-kisiel merged commit 909372d into mainMay 8, 2026
9 checks passed

maciej-kisiel deleted the guglielmoc/SEP-2243_http_standardization_2 branch May 8, 2026 10:39

halter73 mentioned this pull request May 21, 2026
Add RegisterTools API to McpClient for pre-populating tool cache modelcontextprotocol/csharp-sdk#1590
Merged