feat: support claude code oauth/max plans on Portkey

[siddharthsambharia-portkey]

Description

Motivation

Type of Change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation update
• Refactoring (no functional changes)

How Has This Been Tested?

• Unit Tests
• Integration Tests
• Manual Testing

Screenshots (if applicable)

Checklist

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes

Related Issues

[matter-code-review]

Summary By MatterAI

🔄 What Changed

Added support for Claude Code Max plans via Portkey by enhancing Anthropic API configuration. Introduced new endpoint mapping for token counting (/messages/count_tokens) and refined header injection logic for beta features and API versioning.

🔍 Impact of the Change

Enables usage of Anthropic's latest models and features through Portkey, improving flexibility for users. The changes are backward-compatible and align with Anthropic’s evolving API standards.

📁 Total Files Changed

File	ChangeLog
API Config src/providers/anthropic/api.ts	Added messagesCountTokens route and updated header logic to support dynamic beta/version headers for chat completion

🧪 Test Added/Recommended

Recommended

• Add unit test for messagesCountTokens endpoint resolution
• Add integration test validating anthropic-beta and anthropicVersion headers are correctly set
• Test fallback behavior when providerOptions or headers are missing

🔒 Security Vulnerabilities

No security vulnerabilities detected. API key handling remains secure via header injection with fallback precedence.

⏳ Estimated code review effort

LOW (~7 minutes)

Tip

Quality Recommendations

1. Add explicit type for providerOptions to improve type safety

2. Include validation for anthropic-beta and version format to prevent malformed headers

3. Add unit test coverage for endpoint routing logic

♫ Tanka Poem

Code flows through wires,
Claude's mind now opens wide—
Max plans take flight.
Tokens counted, paths aligned,
AI speaks in clearer tones. 🚀

Sequence Diagram

sequenceDiagram
    participant Client
    participant AnthropicAPIConfig
    participant AnthropicAPI

    Note over Client,AnthropicAPIConfig: Initialization

    Client->>AnthropicAPIConfig: chatComplete(request)
    AnthropicAPIConfig->>AnthropicAPIConfig: headers({providerOptions, fn: 'chatComplete'})
    AnthropicAPIConfig-->>AnthropicAPI: X-API-Key = providerOptions.apiKey or requestHeaders['x-api-key']
    AnthropicAPIConfig-->>AnthropicAPI: anthropic-beta = providerOptions.anthropicBeta or 'messages-2023-12-15'
    AnthropicAPIConfig-->>AnthropicAPI: anthropic-version = providerOptions.anthropicVersion or '2023-06-01'

    Client->>AnthropicAPIConfig: getEndpoint('messagesCountTokens')
    AnthropicAPIConfig-->>Client: returns '/messages/count_tokens'

    Note over AnthropicAPI: Request Sent to Anthropic

Loading

[matter-code-review]

Review of Anthropic API configuration changes for header handling, versioning, and new endpoint support.

[narengogi]

pls revert the changes on ln 13 and 14
do not change the precedence order for betaHeader. This would break existing flows

[narengogi]

test

[narengogi]

please sign your commits

[siddharthsambharia-portkey]

please sign your commits

yes sir will do