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What is an agent harness?

An agent harness is the code that orchestrates model calls, tool execution, state, and policy around a base model. It is distinct from the model weights. Prime Agent's harness includes the streaming agent loop, persistent IPython kernel, daemon, sessions, refinement, and provider adapters, all running with the user's OS permissions.

v v0.7.1reviewed 2026-08-09evidence officialsources S001, S003, S007cutoff 2026-08-09
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Model vs harness

An agent harness is the code that orchestrates model calls, tool execution, state, and policy around a base model. It is distinct from the model weights. Prime Agent's harness includes the streaming agent loop, persistent IPython kernel, daemon, sessions, refinement, and provider adapters, all running with the user's OS permissions.

  • S001 supports the route's current claim set.
  • S003 supports the route's current claim set.
  • S007 supports the route's current claim set.

Prime Agent harness

An agent harness is the code that orchestrates model calls, tool execution, state, and policy around a base model. It is distinct from the model weights. Prime Agent's harness includes the streaming agent loop, persistent IPython kernel, daemon, sessions, refinement, and provider adapters, all running with the user's OS permissions.

  • S001 supports the route's current claim set.
  • S003 supports the route's current claim set.
  • S007 supports the route's current claim set.

Trust boundary

Everything here runs inside the local trust boundary. If a section mentions code execution, remember that process separation improves reliability and recovery more than it improves security.

Comparison notes

An agent harness is the code that orchestrates model calls, tool execution, state, and policy around a base model. It is distinct from the model weights. Prime Agent's harness includes the streaming agent loop, persistent IPython kernel, daemon, sessions, refinement, and provider adapters, all running with the user's OS permissions.

  • S001 supports the route's current claim set.
  • S003 supports the route's current claim set.
  • S007 supports the route's current claim set.