Agent Interoperability Engineer - Protocols & Resilience

HushOne, Inc.; Kirkland (WA); Hybrid; USD 120,000 - 190,000; Full time

Benefits offered by this job

Stock options

401(k) with company match

Health, dental & vision insurance

Gym membership

Job summary

HushOne, Inc. is hiring a senior engineer to design and implement versioned MCP and A2A integrations alongside standard APIs, emphasizing robust failure handling and cross-system interoperability.

You will enable discovery, capability negotiation, authentication, and task status management while maintaining conformance tests and a comprehensive support matrix. We operate with an office presence in Kirkland, WA, two garages, and a remote-friendly policy for flexibility around family needs;

Qualifications

• Protocol, API, or distributed application engineering.
• Handle version changes and partial failure deliberately, with examples.
• Design against systems controlled by other organisations without trusting them.
• Test interoperability rather than assuming it from a specification.

Responsibilities

• Implement versioned MCP and A2A integrations alongside ordinary APIs.
• Build discovery, capability negotiation, authentication, task status and error handling.
• Maintain conformance tests and a support matrix; a protocol handshake must never be treated as blanket permission.
• Demonstrate a local tool, an external service and an independent remote agent with explicit permissions and cancellation in the first 90 days.

Skills

Protocol engineering

API design

Distributed systems

Versioning strategies

Interoperability testing

Tools

Conformance testing

Public specifications

Job description

HushOne, Inc. is hiring a senior engineer to design and implement versioned MCP and A2A integrations alongside standard APIs, emphasizing robust failure handling and cross-system interoperability.

You will enable discovery, capability negotiation, authentication, and task status management while maintaining conformance tests and a comprehensive support matrix. We operate with an office presence in Kirkland, WA, two garages, and a remote-friendly policy for flexibility around family needs;