Fixed feature detection for custom base URLsPublic

Agent

Model

Claude Opus 4.5 (latest)

Started

Jan 16, 11:27 AM

Messages69

Downloads0

Summary

Closed, Completed

Understand
Analyzed issue and related code for feature detection.
Understand
Edit
Enhanced detection logic to prioritize provider checks.
Edit
Verify
Summarized changes and updated changelog.
Verify
Cleanup
Committed, pushed changes, and closed issue with comment.
Cleanup

Analyze GitHub issue(s): https://github.com/badlogic/pi-mono/issues/774

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 explore the codebase to understand how feature detection based on base URL works.

Now let me look at the openai-completions provider where the auto-detection logic likely lives:

Let me also check how models are defined and the provider field is used:

Let me check the KnownProvider type to see all known providers:

Analysis of Issue #774

Title: pi-ai auto detection of features based on base url is confusing

Problem: When using a custom base URL for providers like Cerebras (e.g., for proxying LLM calls), model configuration breaks because provider-specific settings (like "no support for developer message") are determined by checking if the URL contains cerebras.ai, rather than using the explicitly configured provider field.

Root Cause

In packages/ai/src/providers/openai-completions.ts, the detectCompatFromUrl() function (lines 495-521) only examines the baseUrl to determine provider-specific compatibility:

typescript

function detectCompatFromUrl(baseUrl: string): Required<OpenAICompat> {	const isZai = baseUrl.includes("api.z.ai");
	const isNonStandard =		baseUrl.includes("cerebras.ai") ||		baseUrl.includes("api.x.ai") ||		baseUrl.includes("mistral.ai") ||		// ...

When a user sets a custom baseUrl (e.g., https://my-proxy.com/v1) but keeps provider: "cerebras", the URL check fails and the model gets incorrect OpenAI-standard settings (like trying to use developer role, which Cerebras doesn't support).

Proposed Fix

Modify detectCompatFromUrl to also check model.provider, giving it precedence over URL-based detection since it's explicitly configured:

File: packages/ai/src/providers/openai-completions.ts

Changes:

Rename detectCompatFromUrl(baseUrl: string) to detectCompat(model: Model<"openai-completions">)
Update the detection logic to check both provider and URL:

typescript

function detectCompat(model: Model<"openai-completions">): Required<OpenAICompat> {	const provider = model.provider;	const baseUrl = model.baseUrl;
	const isZai = provider === "zai" || baseUrl.includes("api.z.ai");
	const isNonStandard =		provider === "cerebras" || baseUrl.includes("cerebras.ai") ||		provider === "xai" || baseUrl.includes("api.x.ai") ||		provider === "mistral" || baseUrl.includes("mistral.ai") ||		baseUrl.includes("chutes.ai") ||		isZai ||		provider === "opencode" || baseUrl.includes("opencode.ai");
	const useMaxTokens =		provider === "mistral" || baseUrl.includes("mistral.ai") ||		baseUrl.includes("chutes.ai");
	const isGrok = provider === "xai" || baseUrl.includes("api.x.ai");
	const isMistral = provider === "mistral" || baseUrl.includes("mistral.ai");
	return {		supportsStore: !isNonStandard,		supportsDeveloperRole: !isNonStandard,		supportsReasoningEffort: !isGrok && !isZai,		supportsUsageInStreaming: true,		maxTokensField: useMaxTokens ? "max_tokens" : "max_completion_tokens",		requiresToolResultName: isMistral,		requiresAssistantAfterToolResult: false,		requiresThinkingAsText: isMistral,		requiresMistralToolIds: isMistral,		thinkingFormat: isZai ? "zai" : "openai",	};}

Update getCompat() to call detectCompat(model) instead of detectCompatFromUrl(model.baseUrl).

Backwards Compatibility: URL-based detection continues to work for users who don't explicitly set a provider. Provider-based detection takes precedence when set, which is the expected behavior since it's an explicit configuration.

Affected Files:

packages/ai/src/providers/openai-completions.ts (only file needing changes)

implement

Now let me update the changelog:

Done. Summary of changes:

File: packages/ai/src/providers/openai-completions.ts

Renamed detectCompatFromUrl(baseUrl) → detectCompat(model)
Added provider-based detection alongside URL-based detection for: cerebras, xai, mistral, zai, opencode
Provider checks take precedence (checked first with ||), maintaining backwards compatibility with URL detection

File: packages/ai/CHANGELOG.md

Added fix entry under [Unreleased]

Users can now use custom base URLs (proxies, gateways) with providers like Cerebras and the correct compatibility settings will apply based on model.provider.

commit and push, close issue with comment

Issue was auto-closed by the commit. Let me add the comment:

Done. Committed (f900eb59), pushed, and issue #774 closed with comment.