Srihari Sriraman shared in

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Implemented fix and enhancements for GitHub issue #909Public

Agent

Model

Claude Opus 4.5 (latest)

Started

Jan 22, 8:46 PM

Messages85

Downloads0

Summary

Closed, Completed

Understand
Reviewed GitHub issue and related comments.
Understand
Understand
Examined relevant code files and documentation.
Understand
Build
Implemented refactoring and header resolution enhancements.
Build
Edit
Updated README with usage instructions.
Edit
Verify
Confirmed all checks passed and implementation correctness.
Verify

Analyze GitHub issue(s): https://github.com/badlogic/pi-mono/issues/909

For each issue:

Read the issue in full, including all comments and linked issues/PRs.
For bugs:
- Ignore any root cause analysis in the issue (likely wrong)
- Read all related code files in full (no truncation)
- Trace the code path and identify the actual root cause
- Propose a fix
For feature requests:
- Read all related code files in full (no truncation)
- Propose the most concise implementation approach
- List affected files and changes needed

Do NOT implement unless explicitly asked. Analyze and propose only.

Let me read the relevant code files to understand the current implementation.

Let me also check the models.json structure and any related documentation.

Analysis: Issue #909

Type: Feature Request

Title: Support environment variables and shell commands in HTTP headers

Current Behavior

In model-registry.ts, the apiKey field supports three resolution patterns via resolveApiKeyConfig():

"!command" - Executes shell command, uses stdout (cached)
Environment variable name - Checks env var, falls back to literal
Literal value - Used directly

However, headers values are not resolved and are used as literal strings only.

Requested Behavior

Apply the same resolution logic to each header value, enabling configurations like:

json

{  "providers": {    "my-proxy": {      "baseUrl": "https://proxy.example.com/v1",      "apiKey": "MY_API_KEY",      "headers": {        "x-portkey-api-key": "PORTKEY_API_KEY"  // <-- resolve from env var      }    }  }}

Breaking Change Analysis

Yes, this is technically a breaking change. If a header value happens to match an environment variable name, the behavior changes:

Before: {"x-header": "HOME"} → literal "HOME"
After: {"x-header": "HOME"} → /Users/username (from env)

However, this edge case is unlikely in practice (header values rarely match env var names by accident), and the new behavior is more useful.

Proposed Implementation

Affected file: packages/coding-agent/src/core/model-registry.ts

Changes:

Add a helper function to resolve all values in a headers object:

typescript

function resolveHeaders(headers: Record<string, string> | undefined): Record<string, string> | undefined {    if (!headers) return undefined;    const resolved: Record<string, string> = {};    for (const [key, value] of Object.entries(headers)) {        const resolvedValue = resolveApiKeyConfig(value);        if (resolvedValue) {            resolved[key] = resolvedValue;        }    }    return Object.keys(resolved).length > 0 ? resolved : undefined;}

Update parseModels() (around line 254) to resolve headers:

typescript

// Before merging headersconst providerHeaders = resolveHeaders(providerConfig.headers);const modelHeaders = resolveHeaders(modelDef.headers);let headers = providerHeaders || modelHeaders     ? { ...providerHeaders, ...modelHeaders }     : undefined;

Update loadBuiltInModels() (around line 196) to resolve override headers:

Update documentation in README.md to document header resolution:

markdown

**Custom headers:**Header values support the same resolution as `apiKey`:- `"!command"` - Execute command, use stdout- Environment variable name - Use env var value- Literal value - Use directly

Files to Modify

File	Change
`packages/coding-agent/src/core/model-registry.ts`	Add `resolveHeaders()` helper, update `parseModels()` and `loadBuiltInModels()`
`packages/coding-agent/README.md`	Document header resolution
`packages/coding-agent/CHANGELOG.md`	Add entry under `## [Unreleased]`

resolveApiKeyConfig should rename that then, implement

Now I'll implement the changes. Starting with the model-registry.ts file:

Now let me update the README documentation:

Now update the changelog:

Now let's run the check to ensure everything compiles correctly:

All checks pass. Let me verify the implementation by reading the modified code:

Implementation complete. Summary of changes:

packages/coding-agent/src/core/model-registry.ts:

Renamed resolveApiKeyConfig → resolveConfigValue (generic name)
Renamed executeApiKeyCommand → executeCommand (generic name)
Added resolveHeaders() helper that applies resolveConfigValue() to each header value
loadBuiltInModels(): resolves override headers before applying
parseModels(): resolves provider and model headers before merging

packages/coding-agent/README.md:

Renamed "API key resolution" → "Value resolution" to cover both apiKey and headers
Updated example to show env var and shell command usage in headers
Added note that header values use the same resolution as apiKey

packages/coding-agent/CHANGELOG.md:

Added breaking change note (header values now resolve env vars)
Added feature entry for header value resolution support

commit and push, add "Thanks, implemented in main"

Done. Committed, pushed, and commented on #909.