GitHub's Pigeon Tool Enables Fine-Grained Delegated Authority for AI Agents

GitHub has introduced Pigeon, a Python-based utility designed to manage delegated authority among AI agents with precision. When an AI agent spawns a sub-agent, it traditionally shares its full API key, granting the sub-agent unrestricted access to sensitive operations such as deploying to production or accessing payment databases. Pigeon addresses this risk by enabling the parent agent to issue a Pigeon Pass—a signed credential that explicitly defines the limited actions and resources the sub-agent is authorized to access. Developed for Python 3.12 and newer, Pigeon operates without requiring a dedicated server. Instead, it modifies existing agent workflows by replacing the practice of copying API keys with calls to delegate() to issue scoped Passes. Before executing any action, the agent calls verify() to confirm the Pass permits the requested operation, returning detailed denial reasons if not authorized. The system enforces strict constraints: sub-agents cannot expand their capabilities, increase resource access, or loosen restrictions inherited from the parent. Attempts to escalate privileges are rejected with clear error codes. This approach confines the potential damage from compromised or malfunctioning sub-agents by bounding their operational scope. Pigeon is not a full identity provider or policy engine but a minimal primitive focused on authority delegation. It complements existing security measures by bounding the "blast radius" of delegated credentials along defined dimensions such as capabilities, resources, and constraints. The tool includes example scripts demonstrating infrastructure deployment, data access, and code management scenarios. Its design emphasizes transparency and enforceability, with verification calls returning structured responses rather than simple booleans. By providing a lightweight mechanism for fine-grained delegation, Pigeon helps organizations maintain tighter control over AI-driven automation, reducing the risk of unintended or malicious actions by sub-agents.