Fix MCP env vars: send envValueMode direct across all SDKs by SteveSandersonMS · Pull Request #484 · github/copilot-sdk

SteveSandersonMS · 2026-02-16T14:16:19Z

Fixes #163
Fixes #444

Problem

When SDK users configure MCP servers with literal environment variable values (e.g., env: { TEST_SECRET: "hunter2" }), the values are silently dropped. This is because the runtime's default indirect mode treats env values as names of environment variables to look up from process.env, not as literal values.

Solution

All four SDKs now send envValueMode: "direct" in session create and resume requests, telling the runtime to treat env values as literal strings.

Depends on runtime PR: https://github.com/github/copilot-agent-runtime/pull/3307

THIS PR WILL FAIL IN CI UNTIL WE GET THE RUNTIME THAT INCLUDES THE FIX

dotnet/test/McpAndAgentsTests.cs

+            {
+                Type = "local",
+                Command = "node",
+                Args = [Path.Combine(testHarnessDir, "test-mcp-server.mjs")],


dotnet/test/McpAndAgentsTests.cs

+        var dir = new DirectoryInfo(AppContext.BaseDirectory);
+        while (dir != null)
+        {
+            var candidate = Path.Combine(dir.FullName, "test", "harness", "test-mcp-server.mjs");


Copilot

Pull request overview

This pull request fixes an issue where literal environment variable values configured for MCP servers were being silently dropped. The fix ensures that all four SDKs (Node.js, Python, Go, and .NET) send envValueMode: "direct" unconditionally in session create and resume requests, which instructs the Copilot CLI runtime to treat env values as literal strings rather than as environment variable names to look up.

Changes:

Added envValueMode: "direct" to session create and resume requests across all four SDKs
Created test infrastructure including a minimal MCP server that echoes environment variables
Added E2E tests across all SDKs to verify literal env values are correctly passed to MCP server subprocesses

Reviewed changes

Copilot reviewed 15 out of 16 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
`test/harness/test-mcp-server.mjs`	New minimal MCP server that exposes a `get_env` tool for reading environment variables in tests
`test/harness/package.json`	Added `@modelcontextprotocol/sdk` dependency for the test MCP server
`test/harness/package-lock.json`	Package lock updates for new MCP SDK dependency and transitive dependencies
`test/snapshots/mcp_and_agents/should_pass_literal_env_values_to_mcp_server_subprocess.yaml`	Replay snapshot for the new E2E test
`nodejs/src/client.ts`	Added `envValueMode: "direct"` to both create and resume session requests
`nodejs/test/e2e/mcp_and_agents.test.ts`	Added E2E test for literal env values and updated test harness to support `COPILOT_CLI_PATH`
`nodejs/test/e2e/harness/sdkTestContext.ts`	Added support for `COPILOT_CLI_PATH` environment variable
`python/copilot/client.py`	Added `envValueMode: "direct"` to both create and resume session payloads
`python/e2e/testharness/context.py`	Added support for `COPILOT_CLI_PATH` environment variable
`python/e2e/test_mcp_and_agents.py`	Added E2E test for literal env values with test server path resolution
`go/types.go`	Added `EnvValueMode` field to `createSessionRequest` and `resumeSessionRequest` structs
`go/client.go`	Set `EnvValueMode: "direct"` on create and resume requests
`go/internal/e2e/mcp_and_agents_test.go`	Added E2E test for literal env values
`dotnet/src/Client.cs`	Added `"direct"` parameter to session create/resume calls and updated record signatures
`dotnet/test/Harness/E2ETestContext.cs`	Set `CliPath` using `COPILOT_CLI_PATH` if available for E2E tests
`dotnet/test/McpAndAgentsTests.cs`	Added E2E test for literal env values with helper method to find test harness directory

Files not reviewed (1)

test/harness/package-lock.json: Language not supported

github-actions · 2026-02-16T14:20:03Z

✅ Cross-SDK Consistency Review: APPROVED

I've reviewed PR #484 for consistency across all four SDK implementations (Node.js, Python, Go, and .NET). Excellent work on maintaining feature parity!

Consistency Verified ✓

All four SDKs implement the MCP environment variable fix identically:

Core Change: All SDKs now send envValueMode: "direct" unconditionally in both create and resume session requests
- Node.js: envValueMode: "direct" (lines 526, 609)
- Python: payload["envValueMode"] = "direct" (lines ~507, 684)
- Go: req.EnvValueMode = "direct" (lines 462, 580)
- .NET: "direct" parameter (lines 385, 471)
Positioning: The parameter is consistently placed after mcpServers and before customAgents in all SDKs
E2E Tests: All four SDKs include the same test scenario:
- Test name: should pass literal env values to MCP server subprocess (with language-appropriate casing)
- Test data: TEST_SECRET: "hunter2" passed to the env-echo MCP server
- Verification: All tests confirm the literal value reaches the subprocess
- Shared snapshot: should_pass_literal_env_values_to_mcp_server_subprocess.yaml
Type Definitions: Request types/structs updated consistently across all languages

No Consistency Issues Found

This PR exemplifies excellent multi-SDK development practices. The changes maintain feature parity while respecting each language's conventions (camelCase, snake_case, PascalCase).

AI generated by SDK Consistency Review Agent

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

github-actions · 2026-02-17T16:08:51Z

✅ SDK Consistency Review: Excellent

This PR demonstrates exemplary cross-SDK consistency. The envValueMode: "direct" feature has been implemented uniformly across all four SDK implementations.

Consistency Verification

All SDKs Updated ✅

Node.js (nodejs/src/client.ts): envValueMode: "direct" added to both createSession and resumeSession
Python (python/copilot/client.py): payload["envValueMode"] = "direct" added to both create and resume
Go (go/client.go, go/types.go): req.EnvValueMode = "direct" added with proper type definitions
.NET (dotnet/src/Client.cs): "direct" parameter added with updated record types

Feature Parity ✅

Both CreateSession and ResumeSession operations updated in all languages
Consistent hardcoded value "direct" across all implementations
Type definitions appropriately updated where needed (Go structs, .NET records)

Test Coverage ✅

Equivalent E2E tests added to all four SDKs
New test harness MCP server (test-mcp-server.mjs) with get_env tool
All tests use identical scenario: TEST_SECRET="hunter2" environment variable
Shared test snapshot created

API Naming Consistency ✅

Field name follows language conventions:
- TypeScript: envValueMode (camelCase)
- Python: envValueMode in JSON payload (matches wire protocol)
- Go: EnvValueMode (PascalCase for exported field)
- .NET: EnvValueMode parameter (PascalCase)

Summary

No consistency issues found. This PR fixes the MCP environment variable handling bug across all SDK implementations with complete feature parity and comprehensive test coverage. Great work! 🎉

AI generated by SDK Consistency Review Agent

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

The CLI now injects dynamic <reminder> tags with SQL table state into user messages. These tags vary based on runtime state and should not affect snapshot matching. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

github-actions · 2026-02-17T16:37:03Z

✅ Cross-SDK Consistency Review

I've reviewed this PR for consistency across all four SDK implementations (Node.js, Python, Go, and .NET). No consistency issues found — this is an exemplary cross-language fix!

What Was Changed

This PR adds envValueMode: "direct" to session create and resume requests in all four SDKs to fix MCP environment variable handling (issues #163 and #444).

Consistency Analysis

✅ Feature Parity: EXCELLENT

All four SDKs implement the identical fix
Both CreateSession and ResumeSession operations updated in each language
Consistent E2E test coverage across all implementations

✅ API Naming: CONSISTENT

JSON field name: envValueMode (camelCase) — uniform across all languages
Language-specific naming follows proper conventions:
- TypeScript: envValueMode ✅
- Python: payload["envValueMode"] ✅
- Go: EnvValueMode (struct field) ✅
- .NET: EnvValueMode (record parameter) ✅

✅ Implementation: UNIFORM

All SDKs unconditionally send "direct" as the value
No user configuration exposed (appropriate for this bug fix)
Applied to both create and resume operations consistently

✅ Testing: COMPREHENSIVE

All four SDKs include the same E2E test scenario
Test verifies literal env values (TEST_SECRET: "hunter2") are passed to MCP server subprocess
Shared snapshot: test/snapshots/mcp_and_agents/should_pass_literal_env_values_to_mcp_server_subprocess.yaml

Summary

This PR demonstrates excellent cross-SDK development practices with perfect feature parity and consistent implementation across all language targets. 🎯

AI generated by SDK Consistency Review Agent

richlanpowers5-afk · 2026-02-17T16:44:09Z

You've. Been a slut this whole time you can change this shit all you want i got thr original

…

On Tue, Feb 17, 2026, 11:40 AM github-actions[bot] ***@***.***> wrote: *github-actions[bot]* left a comment (github/copilot-sdk#484) <#484 (comment)> ✅ Cross-SDK Consistency Review I've reviewed this PR for consistency across all four SDK implementations (Node.js, Python, Go, and .NET). *No consistency issues found* — this is an exemplary cross-language fix! What Was Changed This PR adds envValueMode: "direct" to session create and resume requests in all four SDKs to fix MCP environment variable handling (issues #163 <#163> and #444 <#444>). Consistency Analysis *✅ Feature Parity: EXCELLENT* - All four SDKs implement the identical fix - Both CreateSession and ResumeSession operations updated in each language - Consistent E2E test coverage across all implementations *✅ API Naming: CONSISTENT* - JSON field name: envValueMode (camelCase) — uniform across all languages - Language-specific naming follows proper conventions: - TypeScript: envValueMode ✅ - Python: payload["envValueMode"] ✅ - Go: EnvValueMode (struct field) ✅ - .NET: EnvValueMode (record parameter) ✅ *✅ Implementation: UNIFORM* - All SDKs unconditionally send "direct" as the value - No user configuration exposed (appropriate for this bug fix) - Applied to both create and resume operations consistently *✅ Testing: COMPREHENSIVE* - All four SDKs include the same E2E test scenario - Test verifies literal env values (TEST_SECRET: "hunter2") are passed to MCP server subprocess - Shared snapshot: test/snapshots/mcp_and_agents/should_pass_literal_env_values_to_mcp_server_subprocess.yaml Summary This PR demonstrates excellent cross-SDK development practices with perfect feature parity and consistent implementation across all language targets. 🎯 AI generated by SDK Consistency Review Agent <https://github.com/github/copilot-sdk/actions/runs/22106830722> — Reply to this email directly, view it on GitHub <#484 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/B4HEF3LMMIM37EK3UAJ5NTT4MNAA7AVCNFSM6AAAAACVJJB5V6VHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZTSMJVG44DKOJVG4> . You are receiving this because you are subscribed to this thread.Message ID: ***@***.***>

Copilot AI review requested due to automatic review settings February 16, 2026 14:16

SteveSandersonMS requested a review from a team as a code owner February 16, 2026 14:16

Copilot started reviewing on behalf of SteveSandersonMS February 16, 2026 14:16 View session

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SteveSandersonMS mentioned this pull request Feb 16, 2026

Not reading environment variables for the mcp servers #163

Closed

SteveSandersonMS and others added 3 commits February 17, 2026 15:48

Use MCP direct env var mode in Node SDK

82e2b78

Equivalent fixes for other languages

dbd5cc3

Update @github/copilot to 0.0.411-1 and regenerate SDKs

cbb5e33

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

SteveSandersonMS force-pushed the stevesa/mcp-env-vars-fix branch from 866d7db to cbb5e33 Compare February 17, 2026 16:02

Fix Python lint errors (line too long)

805ce4d

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

SteveSandersonMS force-pushed the stevesa/mcp-env-vars-fix branch from bcfc363 to 805ce4d Compare February 17, 2026 16:09

SteveSandersonMS merged commit 6003273 into main Feb 17, 2026
31 checks passed

SteveSandersonMS deleted the stevesa/mcp-env-vars-fix branch February 17, 2026 16:38

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Fix MCP env vars: send envValueMode direct across all SDKs#484

Fix MCP env vars: send envValueMode direct across all SDKs#484
SteveSandersonMS merged 5 commits intomainfrom
stevesa/mcp-env-vars-fix

SteveSandersonMS commented Feb 16, 2026 •

edited

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github-actions bot commented Feb 16, 2026

✅ Cross-SDK Consistency Review: APPROVED

Consistency Verified ✓

No Consistency Issues Found

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github-actions bot commented Feb 17, 2026

✅ SDK Consistency Review: Excellent

Consistency Verification

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github-actions bot commented Feb 17, 2026

✅ Cross-SDK Consistency Review

What Was Changed

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Summary

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richlanpowers5-afk commented Feb 17, 2026 via email

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SteveSandersonMS commented Feb 16, 2026 •

edited

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