MetaharnessOne record vocabulary
Session lifecycle, tool calls, results, usage and warnings share a common event envelope. Vendor details stay in the adapter.
Read the event protocol →Observe · steer · compare
Many harnesses.
One interface.
Keep the agent’s loop. Give your workflow a consistent way to drive it. Metaharness turns harness runs into a common stream of events, with explicit control and evidence of what happened.
Rust · JSON Lines · CLI first, library second
# Inspect the adapter’s declared contract.
$ metaharness capabilities claude
# Exercise the seam, without a model.
$ metaharness conformance claude
# Same interface. A different harness.
$ metaharness conformance codex No model call. No credential. A first check.
01 / The shape of a run
Your workflow stays outside.
The record crosses the boundary.
Each harness keeps its own loop and tools. Its adapter translates the documented surface into one protocol your process can read and steer.
Your process
Workflow or embedder
Read events.
Send steering commands.
events out ←
JSONL→ commands inThe interface
Metaharness
Normalize the record.
Report the control boundary.
adaptervendor surface
The agent loop
Claude · Codex · b10x
Keep the harness’s loop.
Declare what each arm supports.
Claude Code and Codex expose control seams. The b10x adapter observes its loop; it does not claim an approval seam. Understand the differences →
02 / Three commitments
A shared shape.
Explicit boundaries.
Evidence over assumptions
A constructed environment limits ambient inputs. The run’s own record determines which hermetic claims are proven, missing or unknown.
Read the hermetic contract →Decisions at the boundary
On a supported seam, decide each call from a sealed frame or ask the embedder. Unsupported controls are refused by name.
Explore the control seam →03 / Choose an adapter
Compare the run.
Keep the differences visible.
A common protocol does not make every harness equally controllable. Each adapter documents its version pins, observations and remaining limits.
04 / Start with the contract
Make your next run
an observable one.
Begin with the free conformance vectors. Then connect your workflow through events, commands and a sealed frame.
Open the quickstart