Five protection layers that guard context health, prevent execution loops, and enforce completion quality — so your agents stay sharp through even the longest-running missions.
PROTECTION LAYERS
Long-running agents degrade — context windows fill up, execution loops form, and outputs drift from the original task. Harness prevents all of it, automatically.
Prevent context window pollution
Automatic context compression that preserves critical information while freeing token budget. Your agents stay focused and coherent across hundreds of steps without losing important details.
Break infinite cycles automatically
Tracks edit counts per file and per operation. When an agent exceeds N iterations on the same resource, Harness intervenes — escalating to a human, switching strategy, or halting gracefully.
Validate before you ship
Forces the agent to validate its output against the original task specification before marking a mission complete. No silent failures, no partial deliveries, no drift from requirements.
Offload data, save tokens
Offloads tool results and intermediate files to persistent storage rather than keeping them in the context window. Agents reference stored artifacts by pointer — not by consuming tokens.
Pluggable middleware at every stage
Pluggable middleware triggered before agent start, after completion, and around every tool call. Inject logging, validation, cost controls, compliance checks — anything your workflow requires.
DEEP DIVE 01
Agents running 50+ step missions accumulate massive context. Without compression, they lose coherence, hallucinate, or fail silently. Context Summarization keeps your agents sharp by compressing stale context while preserving every critical detail.
DEEP DIVE 02
Infinite loops are the most expensive failure mode in agentic systems. An agent stuck retrying a failing API call or endlessly editing the same file can burn through thousands of dollars in tokens with no useful output. Loop Detection stops this before it starts.
DEEP DIVE 03
The extensibility layer of Harness. Lifecycle Hooks let you inject custom logic at every stage of agent execution — before start, around each tool call, and after completion. Build compliance, logging, cost controls, and custom validation without modifying agent code.
AGENT LIFECYCLE
From the moment a mission starts to the moment it completes, Harness wraps every step in a protection pipeline — automatically, with zero configuration required.
USE CASES
Every agent benefits from Harness, but these are the scenarios where protection layers become mission-critical.
Context Summarization keeps the agent coherent across hundreds of pages. Virtual FS stores extracted clauses without consuming tokens. Pre-Completion Checklist ensures every contract was processed.
Loop Detection prevents the agent from endlessly editing the same file. If it retries a failing test 5 times, Harness intervenes — switching strategy or escalating to a human reviewer.
Lifecycle Hooks inject compliance checks around every tool call. The before_start hook validates authorization. The Pre-Completion Checklist ensures all transactions were reviewed — not just most.
Virtual FS offloads intermediate datasets to storage instead of keeping them in context. Context Summarization preserves the pipeline state while freeing tokens for the next transformation step.
Loop Detection catches circular delegation between agents. Lifecycle Hooks log every inter-agent handoff for audit. Pre-Completion Checklist validates the final assembled report against all section requirements.
Context Summarization prevents context decay over hours of continuous operation. Loop Detection catches agents stuck retrying unreachable APIs. Lifecycle Hooks enforce rate limits and cost ceilings.