feat: add {file:path} template support for skill MCP env values#2604
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sanoyphilippe wants to merge 3 commits intocode-yeongyu:devfrom
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feat: add {file:path} template support for skill MCP env values#2604sanoyphilippe wants to merge 3 commits intocode-yeongyu:devfrom
sanoyphilippe wants to merge 3 commits intocode-yeongyu:devfrom
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| GitGuardian id | GitGuardian status | Secret | Commit | Filename | |
|---|---|---|---|---|---|
| - | - | Generic High Entropy Secret | 6c89089 | src/features/claude-code-mcp-loader/env-expander.test.ts | View secret |
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5 issues found across 2 files
Confidence score: 2/5
- There is high regression risk because
src/features/claude-code-mcp-loader/env-expander.test.tscurrently codifies behavior that diverges from OpenCode in core cases (~/homedir expansion, config-directory-relative resolution, and missing{file:path}error handling), which can break real-world secret/file template usage. src/features/claude-code-mcp-loader/env-expander.tsexpands file content and then re-expands${...}as env vars, so secret file contents may be unintentionally altered, creating concrete user-facing misconfiguration risk.- The
/tmptest setup insrc/features/claude-code-mcp-loader/env-expander.test.tsis less severe but can cause cross-platform failures and flaky parallel runs, adding uncertainty to validation. - Pay close attention to
src/features/claude-code-mcp-loader/env-expander.tsandsrc/features/claude-code-mcp-loader/env-expander.test.ts- compatibility semantics and expansion order need alignment to avoid breaking OpenCode-style file/env resolution.
Prompt for AI agents (unresolved issues)
Check if these issues are valid — if so, understand the root cause of each and fix them. If appropriate, use sub-agents to investigate and fix each issue separately.
<file name="src/features/claude-code-mcp-loader/env-expander.test.ts">
<violation number="1" location="src/features/claude-code-mcp-loader/env-expander.test.ts:7">
P2: Hardcoded `/tmp` directory breaks cross-platform compatibility and risks test interference during concurrent execution. Use `os.tmpdir()` with `fs.mkdtempSync()` to create isolated temporary directories.</violation>
<violation number="2" location="src/features/claude-code-mcp-loader/env-expander.test.ts:23">
P1: Custom agent: **Opencode Compatibility**
The implementation misses support for `~/` homedir expansion, which is standard in OpenCode's `{file:...}` resolution and its primary documented use case for secrets. Add `~/` support using `os.homedir()` to match OpenCode's native capability.</violation>
<violation number="3" location="src/features/claude-code-mcp-loader/env-expander.test.ts:38">
P1: Custom agent: **Opencode Compatibility**
OpenCode's native behavior throws an error when a `{file:path}` reference is missing. This test explicitly asserts that the original string is returned instead, which deviates from OpenCode and poses a security risk of leaking template literals (like `"{file:.secrets/token}"`) to external services. Update the implementation to throw an error for missing files to match OpenCode, and update this test accordingly.</violation>
<violation number="4" location="src/features/claude-code-mcp-loader/env-expander.test.ts:44">
P1: Custom agent: **Opencode Compatibility**
OpenCode resolves relative file templates against the configuration file's directory, not `process.cwd()`. Using `cwd` will break relative paths in global or project-level configs (e.g., `~/.claude.json`) if the user runs commands from a different directory. Update the implementation to accept the config file's directory as an argument and resolve relative paths against it instead of `cwd`.</violation>
</file>
<file name="src/features/claude-code-mcp-loader/env-expander.ts">
<violation number="1" location="src/features/claude-code-mcp-loader/env-expander.ts:19">
P1: Sequential expansion subjects file secrets to environment variable replacement, potentially corrupting them. File content containing `${...}` sequences will be incorrectly expanded as environment variables.</violation>
</file>
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Reply with feedback, questions, or to request a fix. Tag @cubic-dev-ai to re-run a review.
…ort, error handling
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2 issues found across 2 files (changes from recent commits).
Prompt for AI agents (unresolved issues)
Check if these issues are valid — if so, understand the root cause of each and fix them. If appropriate, use sub-agents to investigate and fix each issue separately.
<file name="src/features/claude-code-mcp-loader/env-expander.ts">
<violation number="1" location="src/features/claude-code-mcp-loader/env-expander.ts:47">
P1: JavaScript's `String.prototype.replace()` interprets special replacement patterns (e.g., `$$` → `$`, `$&` → matched substring) when the replacement is a string. File contents containing `$` characters (bcrypt hashes like `$2a$...` or tokens with `$$`) will be silently corrupted. Use a replacer function `result.replace(placeholder, () => content)` to prevent pattern evaluation and ensure literal string insertion.</violation>
</file>
<file name="src/features/claude-code-mcp-loader/env-expander.test.ts">
<violation number="1" location="src/features/claude-code-mcp-loader/env-expander.test.ts:84">
P1: Test writes to and deletes from the user's real home directory, risking data loss</violation>
</file>
Reply with feedback, questions, or to request a fix. Tag @cubic-dev-ai to re-run a review.
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Summary
{file:path}template support for skill MCP env values, enabling secrets to be read from files at MCP startup{file:...}config capability for skill-embedded MCPsChanges
src/features/claude-code-mcp-loader/env-expander.tsto resolve{file:path}templates before${VAR}expansionexpandFileTemplatesfunction that reads file content with proper error handlingexpandEnvVarsto callexpandFileTemplatesfirst, maintaining backward compatibilityenv-expander.test.tscovering file template resolution, error cases, and integration with existing env var expansionTesting
bun run typecheck bun test src/features/claude-code-mcp-loader/Related Issues
Enables skill-embedded MCPs to authenticate using file-based secrets (e.g., `{file:.secrets/api-token}`), bringing parity with OpenCode's native MCP config `environment` field.
Summary by cubic
Add
{file:path}support for skill MCP env values so secrets load from files at startup, matching OpenCode’s native config. Uses sentinel-based expansion with a safe replacer so${VAR}and file templates can mix without corrupting$patterns; file contents are trimmed and never re-expanded.{file:...}relative to optionalbaseDir(defaults toprocess.cwd()), with~/homedir support.expandEnvVarsInObject(baseDir?).Written for commit c1b02e6. Summary will update on new commits.