open-responses

Implement and debug interoperable LLM APIs using the Open Responses specification.

209|33|Updated Jan 31, 2026
One-click install
npx skills add https://github.com/OpenRouterTeam/skills --skill open-responses
Or copy as Structured Prompt for Agent
Please help me install this Agent Skill.
Skill: open-responses
Source: https://github.com/OpenRouterTeam/skills/tree/main/open-responses
Command: npx skills add https://github.com/OpenRouterTeam/skills --skill open-responses

SYSTEM DOCUMENTATION & REQUIREMENTS

💡 This Skill includes references (resource) components.

What problem does it solve?

This Skill eliminates the friction of building or debugging LLM APIs that work across multiple providers, removing vendor lock-in and inconsistent implementation gaps for teams working with 600+ AI models.

Core Features & Use Cases

  • Full Specification Reference: Covers the complete Open Responses standard including HTTP protocol structure, polymorphic item systems, state machines, SSE streaming, tool architecture, agentic loops, and extension frameworks.
  • Implementation & Debugging Guidance: Provides compliance checklists, error handling rules, concrete streaming sequence examples, and tool call orchestration patterns for building compliant servers and clients.
  • Use Case: Use this Skill to implement a /v1/responses endpoint that supports parallel tool calls, debug streaming event ordering issues, or extend the spec with custom provider-specific item types without breaking client compatibility.

Quick Start

Use the open-responses skill to build a compliant POST /v1/responses endpoint that supports streaming text responses and parallel function tool calls.

Frequently Asked Questions about open-responses

High-intent search queries and answers about installing and using this skill.

FAQPage Schema
How do I build a cross-provider LLM API endpoint that avoids vendor lock-in?

Use the Open Responses open standard specification to build interoperable multi-provider LLM APIs. It provides the HTTP protocol structure, polymorphic item systems, and state machines needed to construct a compliant /v1/responses endpoint that works across 600+ AI models without vendor lock-in.

How does SSE streaming work with tool calling in multi-provider LLM APIs?

SSE streaming processes tool calls by adhering to state machine rules and emitting ordered streaming events. The Open Responses standard defines concrete streaming sequence examples and tool call orchestration patterns to ensure proper event ordering and parallel function execution across providers.

What is the best way to debug streaming event ordering issues in an LLM API?

Debug streaming event ordering issues using Open Responses compliance checklists and error handling rules. The standard provides concrete streaming sequence examples and state machine adherence rules to identify and fix event ordering problems in server endpoint development.

Can I extend the LLM API spec with custom provider-specific item types without breaking client compatibility?

Yes, you can extend the spec with custom provider-specific item types using the Open Responses extension framework. It includes vendor extension governance rules that allow you to add custom items while maintaining client compatibility and API compliance.

How do I implement an agentic loop using the Open Responses standard?

Implement agentic loops by following the Open Responses standard's state machine and tool architecture guidelines. The specification covers agentic loop implementation patterns, tool call orchestration, and SSE event processing required to build compliant multi-provider LLM API servers.

Does the Open Responses standard support parallel function tool calls across different LLM providers?

Yes, the Open Responses standard supports parallel function tool calls across different LLM providers. It provides tool architecture specifications and tool call orchestration patterns to ensure compliant API construction and parallel execution within the /v1/responses endpoint.