feat(source/bigquery): add apiEndpoint field to override BigQuery API host by ayheber · Pull Request #3437 · googleapis/mcp-toolbox

ayheber · 2026-06-16T06:58:12Z

Description

The BigQuery source has no way to set a custom API endpoint today. This
means users who need to route BigQuery traffic through a corporate proxy
or a local emulator (e.g. for governance, audit, or offline testing) have
no supported mechanism — setting HTTPS_PROXY does not work because a
forward proxy tunnels TLS directly to Google and cannot inspect the
request body.

This PR adds an optional apiEndpoint config field that passes
option.WithEndpoint(...) to both the high-level (cloud.google.com/go/bigquery)
and REST (google.golang.org/api/bigquery/v2) clients. Both http:// and
https:// schemes are supported, enabling local emulators as well as
HTTPS proxies. The prebuilt config exposes this via the BIGQUERY_ENDPOINT
environment variable.

PR Checklist

Make sure you reviewed CONTRIBUTING.md
Make sure to open an issue as a bug/issue before writing your code!
Ensure the tests and linter pass
Code coverage does not decrease (if any source code was changed)
Appropriate docs were updated (if necessary)
Make sure to add ! if this involve a breaking change

🛠️ Fixes #2766 🦕

google-cla · 2026-06-16T06:58:29Z

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Code Review

This pull request adds support for overriding the BigQuery API endpoint via a new apiEndpoint configuration option (and BIGQUERY_ENDPOINT environment variable), allowing users to route traffic through a proxy or local emulator. The changes span documentation, prebuilt configurations, and the BigQuery source implementation, including a new NormalizeEndpoint utility and corresponding tests. Feedback on the changes highlights a critical issue in NormalizeEndpoint where stripping trailing slashes from custom paths breaks relative URL resolution in the Google API client library. The reviewer provided code suggestions to preserve trailing slashes for custom paths and to update the test suite accordingly.

… host Adds an optional `apiEndpoint` config field (and `BIGQUERY_ENDPOINT` prebuilt env var) that wires `option.WithEndpoint` into both the high-level and REST BigQuery clients. Enables routing traffic through a corporate proxy or local emulator (http/https both supported). Fixes googleapis#2766 🦕

Stripping trailing slashes from all paths breaks url.URL.ResolveReference for custom path prefixes (e.g. https://proxy.com/v1/). Only strip when the path is the root "/" so relative API paths resolve correctly.

ayheber · 2026-07-02T08:50:59Z

Hi @dishaprakash - following up here since this PR has been open for a couple of weeks without a review pass yet.

This closes #2766 (labeled priority: p1, status: help wanted).

All CI checks I have visibility into are green (lint, CLA, conventional-commits, header-check). The one exception is integration-test-pr, which shows ACTION_REQUIRED (I believe that Cloud Build trigger needs a maintainer to manually approve it for external contributors).

Could someone take a look when you have a chance, and approve the integration test run? Happy to make any changes needed. Thanks!

shobsi

Hi @ayheber,

Thank you for this PR! The implementation looks great, and using option.WithEndpoint() is exactly the right approach here. I did notice that some of the automated checks are currently failing. Could you take a look at the CI logs and see what needs to be fixed? Once the checks are green, we'd be happy to get this merged.

NoClueMike · 2026-07-23T01:29:48Z

👍

Yuan325 · 2026-07-29T04:54:27Z

/gcbrun

Yuan325 · 2026-07-29T05:48:26Z

/gcbrun

…uery API host (#3437) ## Description The BigQuery source has no way to set a custom API endpoint today. This means users who need to route BigQuery traffic through a corporate proxy or a local emulator (e.g. for governance, audit, or offline testing) have no supported mechanism — setting `HTTPS_PROXY` does not work because a forward proxy tunnels TLS directly to Google and cannot inspect the request body. This PR adds an optional `apiEndpoint` config field that passes `option.WithEndpoint(...)` to both the high-level (`cloud.google.com/go/bigquery`) and REST (`google.golang.org/api/bigquery/v2`) clients. Both `http://` and `https://` schemes are supported, enabling local emulators as well as HTTPS proxies. The prebuilt config exposes this via the `BIGQUERY_ENDPOINT` environment variable. ## PR Checklist - [x] Make sure you reviewed [CONTRIBUTING.md](https://github.com/googleapis/mcp-toolbox/blob/main/CONTRIBUTING.md) - [x] Make sure to open an issue as a [bug/issue](https://github.com/googleapis/mcp-toolbox/issues/new/choose) before writing your code! - [x] Ensure the tests and linter pass - [x] Code coverage does not decrease (if any source code was changed) - [x] Appropriate docs were updated (if necessary) - [ ] Make sure to add `!` if this involve a breaking change 🛠️ Fixes #2766 🦕 --------- Co-authored-by: Yuan Teoh <45984206+Yuan325@users.noreply.github.com> Co-authored-by: Yuan Teoh <yuanteoh@google.com> 4da1600

🤖 I have created a release *beep* *boop* --- ## [1.9.0](v1.8.0...v1.9.0) (2026-08-14) ### Features * **groups:** Add ttlMs and cacheScope customization to config ([#3805](#3805)) ([a5d4947](a5d4947)) * **migrate:** Convert toolset to group kind during migration ([#3704](#3704)) ([0adeaa5](0adeaa5)) * **server/mcp:** Introduce generic client extension registry ([#3723](#3723)) ([016245c](016245c)) * **skill:** Add review-prs skill for mcp-toolbox ([#3743](#3743)) ([5b7bacc](5b7bacc)) * **source/bigquery:** Add apiEndpoint field to override BigQuery API host ([#3437](#3437)) ([4da1600](4da1600)) * **source/databaseinsights:** Add databaseinsights source ([#3461](#3461)) ([3b9615d](3b9615d)) * **sources/spanner:** Rename execute_sql_dql to execute_sql_readonly ([#3776](#3776)) ([cf5a0c8](cf5a0c8)) * **tools/bigtable:** Add admin lifecycle and listing tools ([#3596](#3596)) ([801d589](801d589)) * **tools/bigtable:** Bigtable-list-schemas MCP tool ([#3683](#3683)) ([9228c61](9228c61)) * **tools/databaseinsights:** Add Advanced Query Insights tools for AlloyDB ([#3722](#3722)) ([74d18ae](74d18ae)) * **tools/looker:** Add additional tools to allow dashboards to be modified, and their layouts altered. ([#3597](#3597)) ([b2b80fb](b2b80fb)) * **tools:** Add cloud-sql-connect-gce for pg, mysql, mssql ([#3740](#3740)) ([ca58fa4](ca58fa4)) ### Bug Fixes * **auth/mcp:** Derive PRM URL from Toolbox URL ([#3765](#3765)) ([aa30842](aa30842)) * **config:** Ignore environment variables in YAML comments ([#3807](#3807)) ([79aa732](79aa732)), refs [#3793](#3793) * **mcp:** Return Tool execution error for invalid input param ([#3799](#3799)) ([8120197](8120197)) * **prebuilt/cloud-storage:** Declare tool collections as groups ([#3764](#3764)) ([7d468be](7d468be)) * **server/mcp:** Disallow client overriding URL bound parameters ([#3798](#3798)) ([f15a9c7](f15a9c7)) * **server:** Avoid a nil-flusher panic in the SSE handler ([#3520](#3520)) ([947f42f](947f42f)) * **tools/bigquery:** Keep the provider error classification in bigquery-execute-sql ([#3738](#3738)) ([42570b8](42570b8)) * **tools/looker:** Scope the filters quoting rule to values in query description ([#3788](#3788)) ([78eb0b8](78eb0b8)) * **util:** Convert exponent-form JSON numbers in ConvertNumbers ([#3730](#3730)) ([e9713ee](e9713ee)) --- This PR was generated with [Release Please](https://github.com/googleapis/release-please). See [documentation](https://github.com/googleapis/release-please#release-please). --------- Co-authored-by: release-please[bot] <55107282+release-please[bot]@users.noreply.github.com> Co-authored-by: Yuan Teoh <45984206+Yuan325@users.noreply.github.com>

🤖 I have created a release *beep* *boop* --- ## [1.9.0](v1.8.0...v1.9.0) (2026-08-14) ### Features * **groups:** Add ttlMs and cacheScope customization to config ([#3805](#3805)) ([a5d4947](a5d4947)) * **migrate:** Convert toolset to group kind during migration ([#3704](#3704)) ([0adeaa5](0adeaa5)) * **server/mcp:** Introduce generic client extension registry ([#3723](#3723)) ([016245c](016245c)) * **skill:** Add review-prs skill for mcp-toolbox ([#3743](#3743)) ([5b7bacc](5b7bacc)) * **source/bigquery:** Add apiEndpoint field to override BigQuery API host ([#3437](#3437)) ([4da1600](4da1600)) * **source/databaseinsights:** Add databaseinsights source ([#3461](#3461)) ([3b9615d](3b9615d)) * **sources/spanner:** Rename execute_sql_dql to execute_sql_readonly ([#3776](#3776)) ([cf5a0c8](cf5a0c8)) * **tools/bigtable:** Add admin lifecycle and listing tools ([#3596](#3596)) ([801d589](801d589)) * **tools/bigtable:** Bigtable-list-schemas MCP tool ([#3683](#3683)) ([9228c61](9228c61)) * **tools/databaseinsights:** Add Advanced Query Insights tools for AlloyDB ([#3722](#3722)) ([74d18ae](74d18ae)) * **tools/looker:** Add additional tools to allow dashboards to be modified, and their layouts altered. ([#3597](#3597)) ([b2b80fb](b2b80fb)) * **tools:** Add cloud-sql-connect-gce for pg, mysql, mssql ([#3740](#3740)) ([ca58fa4](ca58fa4)) ### Bug Fixes * **auth/mcp:** Derive PRM URL from Toolbox URL ([#3765](#3765)) ([aa30842](aa30842)) * **config:** Ignore environment variables in YAML comments ([#3807](#3807)) ([79aa732](79aa732)), refs [#3793](#3793) * **mcp:** Return Tool execution error for invalid input param ([#3799](#3799)) ([8120197](8120197)) * **prebuilt/cloud-storage:** Declare tool collections as groups ([#3764](#3764)) ([7d468be](7d468be)) * **server/mcp:** Disallow client overriding URL bound parameters ([#3798](#3798)) ([f15a9c7](f15a9c7)) * **server:** Avoid a nil-flusher panic in the SSE handler ([#3520](#3520)) ([947f42f](947f42f)) * **tools/bigquery:** Keep the provider error classification in bigquery-execute-sql ([#3738](#3738)) ([42570b8](42570b8)) * **tools/looker:** Scope the filters quoting rule to values in query description ([#3788](#3788)) ([78eb0b8](78eb0b8)) * **util:** Convert exponent-form JSON numbers in ConvertNumbers ([#3730](#3730)) ([e9713ee](e9713ee)) --- This PR was generated with [Release Please](https://github.com/googleapis/release-please). See [documentation](https://github.com/googleapis/release-please#release-please). --------- Co-authored-by: release-please[bot] <55107282+release-please[bot]@users.noreply.github.com> Co-authored-by: Yuan Teoh <45984206+Yuan325@users.noreply.github.com> 5de8f13

🤖 I have created a release *beep* *boop* --- ## [1.9.0](googleapis/mcp-toolbox@v1.8.0...v1.9.0) (2026-08-14) ### Features * **groups:** Add ttlMs and cacheScope customization to config ([googleapis#3805](googleapis#3805)) ([a5d4947](googleapis@a5d4947)) * **migrate:** Convert toolset to group kind during migration ([googleapis#3704](googleapis#3704)) ([0adeaa5](googleapis@0adeaa5)) * **server/mcp:** Introduce generic client extension registry ([googleapis#3723](googleapis#3723)) ([016245c](googleapis@016245c)) * **skill:** Add review-prs skill for mcp-toolbox ([googleapis#3743](googleapis#3743)) ([5b7bacc](googleapis@5b7bacc)) * **source/bigquery:** Add apiEndpoint field to override BigQuery API host ([googleapis#3437](googleapis#3437)) ([4da1600](googleapis@4da1600)) * **source/databaseinsights:** Add databaseinsights source ([googleapis#3461](googleapis#3461)) ([3b9615d](googleapis@3b9615d)) * **sources/spanner:** Rename execute_sql_dql to execute_sql_readonly ([googleapis#3776](googleapis#3776)) ([cf5a0c8](googleapis@cf5a0c8)) * **tools/bigtable:** Add admin lifecycle and listing tools ([googleapis#3596](googleapis#3596)) ([801d589](googleapis@801d589)) * **tools/bigtable:** Bigtable-list-schemas MCP tool ([googleapis#3683](googleapis#3683)) ([9228c61](googleapis@9228c61)) * **tools/databaseinsights:** Add Advanced Query Insights tools for AlloyDB ([googleapis#3722](googleapis#3722)) ([74d18ae](googleapis@74d18ae)) * **tools/looker:** Add additional tools to allow dashboards to be modified, and their layouts altered. ([googleapis#3597](googleapis#3597)) ([b2b80fb](googleapis@b2b80fb)) * **tools:** Add cloud-sql-connect-gce for pg, mysql, mssql ([googleapis#3740](googleapis#3740)) ([ca58fa4](googleapis@ca58fa4)) ### Bug Fixes * **auth/mcp:** Derive PRM URL from Toolbox URL ([googleapis#3765](googleapis#3765)) ([aa30842](googleapis@aa30842)) * **config:** Ignore environment variables in YAML comments ([googleapis#3807](googleapis#3807)) ([79aa732](googleapis@79aa732)), refs [googleapis#3793](googleapis#3793) * **mcp:** Return Tool execution error for invalid input param ([googleapis#3799](googleapis#3799)) ([8120197](googleapis@8120197)) * **prebuilt/cloud-storage:** Declare tool collections as groups ([googleapis#3764](googleapis#3764)) ([7d468be](googleapis@7d468be)) * **server/mcp:** Disallow client overriding URL bound parameters ([googleapis#3798](googleapis#3798)) ([f15a9c7](googleapis@f15a9c7)) * **server:** Avoid a nil-flusher panic in the SSE handler ([googleapis#3520](googleapis#3520)) ([947f42f](googleapis@947f42f)) * **tools/bigquery:** Keep the provider error classification in bigquery-execute-sql ([googleapis#3738](googleapis#3738)) ([42570b8](googleapis@42570b8)) * **tools/looker:** Scope the filters quoting rule to values in query description ([googleapis#3788](googleapis#3788)) ([78eb0b8](googleapis@78eb0b8)) * **util:** Convert exponent-form JSON numbers in ConvertNumbers ([googleapis#3730](googleapis#3730)) ([e9713ee](googleapis@e9713ee)) --- This PR was generated with [Release Please](https://github.com/googleapis/release-please). See [documentation](https://github.com/googleapis/release-please#release-please). --------- Co-authored-by: release-please[bot] <55107282+release-please[bot]@users.noreply.github.com> Co-authored-by: Yuan Teoh <45984206+Yuan325@users.noreply.github.com> 5de8f13

ayheber requested review from a team as code owners June 16, 2026 06:58

blunderbuss-gcf Bot assigned Yuan325 Jun 16, 2026

gemini-code-assist Bot reviewed Jun 16, 2026

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Comment thread internal/sources/bigquery/bigquery.go

Comment thread internal/sources/bigquery/bigquery_test.go

ayheber force-pushed the feat/bigquery-endpoint-override branch from ca6f6b6 to 392fdbd Compare June 16, 2026 07:07

ayheber added 2 commits June 18, 2026 11:13

fix(source/bigquery): preserve trailing slash on custom endpoint paths

248f9a1

Stripping trailing slashes from all paths breaks url.URL.ResolveReference for custom path prefixes (e.g. https://proxy.com/v1/). Only strip when the path is the root "/" so relative API paths resolve correctly.

ayheber force-pushed the feat/bigquery-endpoint-override branch from 7ae65f1 to 248f9a1 Compare June 18, 2026 08:14

Yuan325 added product: bigquery BigQuery priority: p1 Important issue which blocks shipping the next release. Will be fixed prior to next release. labels Jul 15, 2026

This was referenced Jul 22, 2026

Route BigQuery API calls through a proxy #2766

Closed

feat(bigquery): add proxy support for API calls #2941

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shobsi approved these changes Jul 22, 2026

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NoClueMike approved these changes Jul 23, 2026

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Yuan325 added the release candidate Use label to signal PR should be included in the next release. label Jul 29, 2026

Merge branch 'main' into feat/bigquery-endpoint-override

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Yuan325 approved these changes Jul 29, 2026

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fix lint

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Yuan325 enabled auto-merge (squash) July 29, 2026 05:48

Yuan325 merged commit 4da1600 into googleapis:main Jul 29, 2026
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release-please Bot mentioned this pull request Jul 29, 2026

chore(main): release 1.9.0 #3744

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BrewTestBot mentioned this pull request Aug 14, 2026

mcp-toolbox 1.9.0 Homebrew/homebrew-core#298753

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feat(source/bigquery): add apiEndpoint field to override BigQuery API host - #3437

feat(source/bigquery): add apiEndpoint field to override BigQuery API host#3437
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