feat: add native OpenRouter provider

[subtleGradient]

Summary

Adds OpenRouter as a first-class native provider in CrewAI, enabling direct access to 300+ models through a unified API.

Changes

• Register "openrouter" in SUPPORTED_NATIVE_PROVIDERS
• Add provider mapping and validation in LLM class
• Create new OpenRouterCompletion class extending OpenAICompletion
• Add 25 unit tests covering all functionality

Usage

from crewai import LLM

llm = LLM(model="openrouter/anthropic/claude-4.5-sonnet")

Verified Working Example

This exact script was tested and produces the output shown below:

#!/usr/bin/env -S uv run --script
# /// script
# requires-python = ">=3.10"
# dependencies = [
#     "crewai @ git+https://github.com/subtleGradient/crewAI.git@feat/openrouter-provider#subdirectory=lib/crewai",
# ]
# ///
"""Native OpenRouter provider test (PR #4208). Requires OPENROUTER_API_KEY env var."""

from crewai import LLM, Agent, Crew, Task

# Native OpenRouter provider - no base_url needed!
llm = LLM(model="openrouter/anthropic/claude-4.5-sonnet")

agent = Agent(
    role="Assistant", goal="Answer concisely", backstory="Helpful AI.", llm=llm
)
task = Task(
    description="What is 2 + 2? One word.", expected_output="A number", agent=agent
)
result = Crew(agents=[agent], tasks=[task]).kickoff()

print(f"Result: {result}")

Actual Output (verified):

Installed 133 packages in 81ms
Result: Four

Why

While OpenRouter works today via LiteLLM's openrouter/ prefix, a native provider offers:

• Proper OPENROUTER_API_KEY environment variable support (not OPENAI_API_KEY)
• OpenRouter-specific headers (HTTP-Referer, X-Title) for attribution
• Cleaner integration without LiteLLM dependency for simple use cases

Implementation Details

OpenRouterCompletion extends OpenAICompletion (since OpenRouter is OpenAI-compatible) and:

• Overrides base_url to https://openrouter.ai/api/v1
• Uses OPENROUTER_API_KEY instead of OPENAI_API_KEY
• Adds OpenRouter-specific headers for rankings attribution
• Returns True in model validation (like Azure) since OpenRouter proxies 300+ models

Testing

• 25 unit tests covering initialization, API key handling, header injection, and context window
• Verified working locally with anthropic/claude-4.5-sonnet model

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[Copilot]

Pull request overview

This pull request adds OpenRouter as a first-class native provider in CrewAI, enabling direct access to 300+ models through a unified OpenAI-compatible API. The implementation extends the existing OpenAICompletion class and adds proper support for OpenRouter-specific features including API key management and attribution headers.

Key changes:

• Introduces OpenRouterCompletion class that extends OpenAICompletion with OpenRouter-specific configuration
• Registers "openrouter" in the supported native providers list and adds routing logic in the LLM factory
• Adds comprehensive test coverage for initialization, API key handling, header injection, and context window size

Reviewed changes

Copilot reviewed 4 out of 6 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
lib/crewai/src/crewai/llm.py	Registers "openrouter" in SUPPORTED_NATIVE_PROVIDERS and adds provider mapping and routing logic
lib/crewai/src/crewai/llms/providers/openrouter/completion.py	Implements OpenRouterCompletion class with OpenRouter-specific API endpoint, environment variables, and attribution headers
lib/crewai/src/crewai/llms/providers/openrouter/init.py	Empty module initialization file for the openrouter provider package
lib/crewai/tests/llms/providers/openrouter/test_completion.py	Comprehensive test suite covering initialization, API key handling, site attribution, header injection, and integration scenarios
lib/crewai/tests/llms/providers/openrouter/init.py	Empty test module initialization file
lib/crewai/tests/llms/providers/init.py	Empty test module initialization file

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[github-actions]

This PR is stale because it has been open for 45 days with no activity.