DCP Harness

dcp-harness is a lightweight evidence-producing shell for Auto Research. It wraps Claude Code CLI, controls the agent's external actions, records the run, performs the registered DCP ablations, and writes a Bundle that anyone can check offline with dcp-audit.

The wrapper gives the agent only file tools. Claude's shell, Web, MCP, and subagent tools are disabled. The only external action is a strict JSON file. The harness can execute a task experiment or fetch an allowlisted HTTPS URL, then records the request, raw response, model-visible text, workspace change, model identity, and receipt hashes before starting a fresh model session. Only the main run may use live Web access. Challengers and Gate 3 branches get an exact replay of URLs observed by the main run.

A small task adapter supplies task semantics, private evaluation, baseline, and truthful or neutral experiment feedback. Private scores are opened only after every candidate in a phase has committed. The adapter registers all thresholds and sample counts before the main run. It also supplies SHA-256 digests for the private verifier, held-out units, baseline policy, and feedback policies; these materials are rechecked before every phase. The harness fills mechanical evidence from the frozen ledger, invokes the unchanged dcp-audit kernel, and immediately checks that the resulting Bundle replays exactly.

Quickstart

python -m pip install dcp-harness
dcp-harness init my-audit
dcp-harness doctor --config my-audit/dcp-harness.json
dcp-harness run --config my-audit/dcp-harness.json --run my-audit/run-001
dcp verify my-audit/run-001/bundle

The commands can also be run separately and resumed safely.

dcp-harness capture   --config my-audit/dcp-harness.json --run my-audit/run-001
dcp-harness challenge --config my-audit/dcp-harness.json --run my-audit/run-001
dcp-harness gate3     --config my-audit/dcp-harness.json --run my-audit/run-001
dcp-harness finalize  --config my-audit/dcp-harness.json --run my-audit/run-001
dcp-harness status    --config my-audit/dcp-harness.json --run my-audit/run-001

Trust boundary

The harness owns agent execution, action mediation, Web capture and replay, randomization, checkpoints, receipts, and append-only ledgers. The Python task adapter is trusted only for the parts that necessarily depend on the task. It prepares public files, runs the private verifier, and defines truthful and neutral observations. assemble_evidence() derives scores, hashes, counts, and branch records mechanically. Its AuditAttestations input contains the small set of task-specific judgments that cannot be inferred from bytes. Every attestation defaults to false.

The model API connection is infrastructure transport, not a research Web channel. In container mode the agent has no tool capable of starting an arbitrary network request. A task adapter that talks to another service must treat that service as a registered experiment and return its observation through the audited action channel.

Current scope

The alpha supports one local auditor, Claude Code CLI, Docker isolation, allowlisted HTTPS capture, exact observed-URL replay, Gate 2 challenges, Gate 3 paired feedback and sham branches, pre-action infrastructure replacement, resumable phases, and deterministic local Bundles. Host mode is available for development but cannot attest private isolation. Local Bundles always retain formal_certificate_issued=false; formal countersigning belongs to a future external registry rather than this package.

See the repository usage guide for the complete CLI and Python examples.

Licensed under Apache-2.0.