CONTRACT-001 Audit: DDx-Owned Responsibilities vs DDx Implementation

Audit date: 2026-04-17

Scope audited from CONTRACT-001:

Agent execution substrate
Execution and metric substrate
Git-context execution mechanics
Always-on runtime metrics and provenance
DDx-owned rows in the Post-Cycle HELIX Behavior table

Resolution legend:

code-link means the claimed DDx capability exists in ~/Projects/ddx/cli and the cited file:line is the implementation anchor.
new-DDx-bead means the capability is still DDx-owned but not fully shipped; the cited DDx tracker bead carries deterministic acceptance.
HELIX-backport would mean the capability should move back to HELIX with a contract amendment diff. No row required that outcome in this audit.

This audit does not amend CONTRACT-001 ownership. No amendment-notification bead was filed in HELIX because every unresolved DDx-owned claim was resolved by a new DDx-side bead instead of changing ownership or deleting a DDx responsibility.

Agent execution substrate

DDx-owned responsibility	Actual DDx implementation audit	Terminal resolution
`ddx agent run` as the general harness interface	DDx ships a top-level `agent` surface plus `agent run`, with harness dispatch, profile routing, quorum, session logging, and prompt execution.	`code-link`: `~/Projects/ddx/cli/cmd/agent_cmd.go:28`, `~/Projects/ddx/cli/cmd/agent_cmd.go:109`
`ddx agent execute-bead <bead-id> [--from <rev>] [--no-merge]` as the canonical git-aware single-bead execution primitive	DDx ships the CLI entrypoint, the isolated-worktree worker, and the landing path that merges or preserves the result.	`code-link`: `~/Projects/ddx/cli/cmd/agent_execute_bead.go:26`, `~/Projects/ddx/cli/internal/agent/execute_bead.go:360`, `~/Projects/ddx/cli/internal/agent/execute_bead_land.go:557`
`ddx agent execute-loop [--once] [--poll-interval <duration>]` as the canonical single-project queue-drain primitive	DDx ships execute-loop, the queue-drain worker, and the server worker submission path for background execution.	`code-link`: `~/Projects/ddx/cli/cmd/agent_cmd.go:1255`, `~/Projects/ddx/cli/internal/agent/execute_bead_loop.go:174`, `~/Projects/ddx/cli/internal/server/workers.go:180`
Standard harness/model/effort/preset controls available through the DDx agent surface	DDx exposes harness/model/provider/model-ref/effort/profile controls on `agent run`, `execute-bead`, and `execute-loop`.	`code-link`: `~/Projects/ddx/cli/cmd/agent_cmd.go:32`, `~/Projects/ddx/cli/cmd/agent_cmd.go:118`, `~/Projects/ddx/cli/cmd/agent_cmd.go:1324`, `~/Projects/ddx/cli/cmd/agent_execute_bead.go:73`
Session capture, transcript capture, and runtime evidence capture	DDx writes per-run session logs, emits execute-bead prompt/manifest/result artifacts, and records worker/event logs for managed loop workers.	`code-link`: `~/Projects/ddx/cli/internal/agent/agent_runner.go:132`, `~/Projects/ddx/cli/internal/agent/execute_bead.go:756`, `~/Projects/ddx/cli/internal/server/workers.go:218`

Execution and Metric Substrate

DDx-owned responsibility	Actual DDx implementation audit	Terminal resolution
Graph-authored execution documents as authoritative definitions	DDx parses `ddx.execution` frontmatter into `DocExecDef`, projects it into the doc graph, and validates/runs execution definitions against graph artifacts.	`code-link`: `~/Projects/ddx/cli/internal/docgraph/frontmatter.go:23`, `~/Projects/ddx/cli/internal/docgraph/docgraph.go:76`, `~/Projects/ddx/cli/internal/exec/store.go:130`
Immutable execution runs stored in the DDx execution substrate	DDx persists run manifests and result bundles under `.ddx/exec/runs` plus attachment directories with atomic bundle writes.	`code-link`: `~/Projects/ddx/cli/internal/exec/store.go:52`, `~/Projects/ddx/cli/internal/exec/store.go:171`, `~/Projects/ddx/cli/internal/exec/store.go:407`
Metric projection over execution runs	DDx aggregates execution evidence into per-bead metrics and broader process metrics/cost reports.	`code-link`: `~/Projects/ddx/cli/cmd/bead_metrics.go:33`, `~/Projects/ddx/cli/internal/processmetrics/processmetrics.go:24`, `~/Projects/ddx/cli/internal/processmetrics/processmetrics.go:133`
Required execution semantics sufficient to decide merge vs preserve	DDx has dormant gate machinery (`evaluateRequiredGates`, `checks.json`), but managed execute-bead/execute-loop paths do not currently wire governing IDs/worktree context into pre-land gate evaluation.	`new-DDx-bead`: `ddx-3e7f8213`
Metric ratchet evaluation sufficient to decide merge vs preserve	DDx stores metric definitions, comparisons, and thresholds, but managed bead landing does not yet preserve attempts based on ratchet outcomes.	`new-DDx-bead`: `ddx-b3e942d6`

Git-Context Execution Mechanics

DDx-owned responsibility	Actual DDx implementation audit	Terminal resolution
Dirty-tree checkpointing before managed execution	DDx ships a manual `ddx checkpoint` command, but managed execute-bead/execute-loop do not automatically checkpoint a dirty parent tree before spawning the worker worktree.	`new-DDx-bead`: `ddx-91bc770a`
Isolated worktree execution	DDx creates per-attempt worktrees under `$TMPDIR/ddx-exec-wt/.execute-bead-wt-*` and runs the harness inside that isolated tree.	`code-link`: `~/Projects/ddx/cli/internal/agent/execute_bead.go:193`, `~/Projects/ddx/cli/internal/agent/execute_bead.go:207`, `~/Projects/ddx/cli/internal/agent/execute_bead.go:394`
Preserved hidden refs for non-landed attempts	DDx preserves failed/conflicted/no-merge results under `refs/ddx/iterations/...`.	`code-link`: `~/Projects/ddx/cli/internal/agent/execute_bead_orchestrator.go:19`, `~/Projects/ddx/cli/internal/agent/execute_bead_orchestrator.go:170`, `~/Projects/ddx/cli/internal/agent/execute_bead_land.go:654`
Rebase only to prepare fast-forward landing	DDx actually lands by fast-forward-or-merge and explicitly preserves replay fidelity by avoiding worker-commit rewrite. The shipped implementation satisfies the git-safety intent without a rebase activity.	`code-link`: `~/Projects/ddx/cli/internal/agent/execute_bead_land.go:11`, `~/Projects/ddx/cli/internal/agent/execute_bead_land.go:31`, `~/Projects/ddx/cli/internal/agent/execute_bead_land.go:606`
Fast-forward landing when merge-eligible	DDx fast-forwards the target ref directly when the current tip still equals `BaseRev`.	`code-link`: `~/Projects/ddx/cli/internal/agent/execute_bead_land.go:606`
Guaranteed worktree cleanup after landing or preservation	DDx removes per-attempt worker worktrees with deferred cleanup and prunes orphaned worktrees before subsequent runs.	`code-link`: `~/Projects/ddx/cli/internal/agent/execute_bead.go:399`, `~/Projects/ddx/cli/internal/agent/execute_bead_orchestrator.go:330`, `~/Projects/ddx/cli/internal/agent/execute_bead_land.go:649`

Always-On Runtime Metrics and Provenance

DDx-owned responsibility	Actual DDx implementation audit	Terminal resolution
harness	Captured on execute-bead results and session entries.	`code-link`: `~/Projects/ddx/cli/internal/agent/execute_bead.go:625`, `~/Projects/ddx/cli/internal/agent/types.go:111`
model	Captured on execute-bead results and session entries.	`code-link`: `~/Projects/ddx/cli/internal/agent/execute_bead.go:627`, `~/Projects/ddx/cli/internal/agent/types.go:114`
session ID	Generated per managed execute-bead attempt and persisted in result/session records.	`code-link`: `~/Projects/ddx/cli/internal/agent/execute_bead.go:441`, `~/Projects/ddx/cli/internal/agent/execute_bead.go:628`, `~/Projects/ddx/cli/internal/agent/types.go:104`
elapsed duration	Captured as `duration_ms` on execute-bead results and session entries.	`code-link`: `~/Projects/ddx/cli/internal/agent/execute_bead.go:521`, `~/Projects/ddx/cli/internal/agent/execute_bead.go:629`, `~/Projects/ddx/cli/internal/agent/types.go:129`
token usage	Captured from harness results and persisted in execute-bead results, usage artifacts, and session entries.	`code-link`: `~/Projects/ddx/cli/internal/agent/execute_bead.go:464`, `~/Projects/ddx/cli/internal/agent/execute_bead.go:541`, `~/Projects/ddx/cli/internal/agent/types.go:125`
cost	Captured from harness results and persisted in execute-bead results, usage artifacts, and session entries.	`code-link`: `~/Projects/ddx/cli/internal/agent/execute_bead.go:468`, `~/Projects/ddx/cli/internal/agent/execute_bead.go:546`, `~/Projects/ddx/cli/internal/agent/types.go:128`
base revision	Captured before worktree creation and persisted in execute-bead results, manifests, and session entries.	`code-link`: `~/Projects/ddx/cli/internal/agent/execute_bead.go:388`, `~/Projects/ddx/cli/internal/agent/execute_bead.go:623`, `~/Projects/ddx/cli/internal/agent/types.go:133`
result revision	Captured from the worker or land step and persisted in execute-bead results and session entries.	`code-link`: `~/Projects/ddx/cli/internal/agent/execute_bead.go:508`, `~/Projects/ddx/cli/internal/agent/execute_bead.go:624`, `~/Projects/ddx/cli/internal/agent/execute_bead_land.go:743`, `~/Projects/ddx/cli/internal/agent/types.go:134`

Post-Cycle HELIX Behavior Table: DDx-Owned Rows

DDx-owned responsibility	Actual DDx implementation audit	Terminal resolution
Closing SHA sync	Execute-loop closes merged work with the landed `result_rev` as `closing_commit_sha`.	`code-link`: `~/Projects/ddx/cli/internal/agent/execute_bead_loop.go:406`, `~/Projects/ddx/cli/internal/bead/store.go:787`
Build gate (pre-merge check)	DDx has gate-evaluation scaffolding but the managed landing paths do not currently enforce a pre-merge build gate before land.	`new-DDx-bead`: `ddx-3e7f8213`
Retry suppression	DDx writes `execute-loop-retry-after`, filters retry-parked beads out of `ReadyExecution()`, and returns `retry_after` in execute-loop results. The remaining gap is blocker surfacing, not cooldown creation/filtering.	`code-link`: `~/Projects/ddx/cli/internal/bead/store.go:624`, `~/Projects/ddx/cli/internal/bead/store.go:1015`, `~/Projects/ddx/cli/internal/agent/execute_bead_loop.go:545`
Orphan worktree recovery	DDx recovers stale execute-bead worktrees before spawning a new worker.	`code-link`: `~/Projects/ddx/cli/cmd/agent_execute_bead.go:147`, `~/Projects/ddx/cli/internal/agent/execute_bead_orchestrator.go:330`

Notes

DDx blocker surfacing is the only audited item where cooldown state exists in the substrate but is not yet fully surfaced through the operator query surface; that gap is tracked as ddx-4802a7b3.
The known gap “no structured event when HELIX injects a supervisory bead” is outside this matrix because queue injection is HELIX-owned in CONTRACT-001’s Post-Cycle table, not a DDx-owned responsibility row.
Existing DDx/HELIX contract ownership remains unchanged by this audit pass.