Agent-Client Capability Parity Tracker

Status: Living record — the external coding clients change weekly; this is the dated, owned source of truth for what each does and what DPF depends on / should adopt. Owner: Enterprise Architect persona / dpf-platform:dpf-architecture-review. Refresh cadence: Monthly (see “Refresh ritual”). Last full refresh: 2026-06-20. Last verified: 2026-08-12 (Codex MCP host-registry acceptance — see update below). Standard it serves: docs/architecture/context-engineering-standards.md.

Why this exists

DPF runs across, and is driven by, external coding agents (Claude Code, Codex, Grok Build, OpenCode) plus our own native local LLM. Their context/memory/tool mechanisms change weekly — new token-savers ship (deferred tools, code-execution), conventions converge (AGENTS.md), and behaviours regress (the prompt-cache TTL silently reverted 1h → 5m). A point-in-time analysis decays fast. This tracker keeps the design criteria applicable to subsequent changes by recording, per client, the capabilities we depend on or could adopt, with a last-verified date and a DPF adoption status, so the monthly scan diffs against something concrete and files follow-up work.

Adoption status legend: ✅ adopted · ◐ partial/planned · ⬜ not adopted · ➖ n/a · ⚠️ regression to track.

Capability matrix (verified 2026-06-20)

Sources for the row data are catalogued in the design spec appendix (2026-06-20-context-engineering-tool-efficiency-design.md).

2026-06-26 refresh (delivery-surface sweep)

Verified 2026-06-26 against the delivery-surface optimization study (docs/superpowers/specs/2026-06-26-delivery-surface-optimization-study-design.md). Deltas since the 2026-06-20 full refresh:

• Prompt-cache emission (Anthropic): ⬜→◐ shipped — DPF now emits cache_control:{type:"ephemeral"} on the stable system prefix for the Anthropic /messages path (BI-79A5C00F, PR #2447 merged; apps/web/lib/routing/anthropic-cache.ts). 5-minute TTL; 1-hour TTL still a follow-up (needs the extended-cache beta header). OpenAI/xAI caching remains automatic; cloud hit-rate observability still ⬜.
• Prompt-cache TTL: ⚠️ Anthropic default remains 5 minutes (reverted from 1h ~2026-03) — re-confirm each refresh; it changes the break-even for long sessions.
• Deterministic guards (hooks): Codex hooks are now officially documented (plugin-bundled + managed-trust); DPF has structural hook wiring for Claude/Codex/Grok (packages/dpf-skill-pack/hooks/plugin-hooks-wired.test.mjs). Functional proof on Codex/Grok still pending (BI-14E9F7CE), including the Grok GROK_PLUGIN_ROOT vs CLAUDE_PLUGIN_ROOT portability seam.
• Lean tool surface: external CLI core-tier discovery (~29 tools) is the default for clients without proven host-side lazy attachment. Claude Code and Codex keep the full authorized server catalogue for their native lazy registries; Grok/generic/unknown callers keep core unless they opt into ?tier=full. Core includes WWMD (principle_decide, wiki_query) for clients without host ToolSearch.
• Code-graph for external sessions: ⬜→◐ a code-graph-first standing rule added to AGENTS.md §8 for direct Claude/Codex/Grok sessions (BI-0FD9E685).
• Unified WIP across surfaces: workroom-plane foundation shipped (BI-937128F6; apps/web/lib/build/unified-wip.ts) + §17 doctrine — the unit of WIP is the Workroom, not the Build Studio build. The enforced admission cap is now wired to that plane: the two build-entry gates (createFeatureBuild, promote_to_build_studio) derive their decision from the unified, pool-aware pressure (apps/web/lib/build/unified-wip-query.ts → decideUnifiedWip), so a promote is blocked only when the finite pool it contends on (gatingPool) is saturated across ALL surfaces — not a BS-only build count. Per-pool capacities are named constants in wip-cap.ts (WIP_POOL_CAPACITY); the live bs-sandbox limit stays BUILD_WIP_CAP=3 (unchanged). bs-sandbox pressure is still read from the authoritative FeatureBuild count — build-studio workroom status is not synced on build terminality, so counting those workrooms would mis-gate.
• Cross-surface review: golden-triangle activation policy for independent deliberation on external artifacts (BI-A245FE00; apps/web/lib/deliberation/external-review-activation.ts).
• MCP token var: active standard is DPF_MCP_BEARER_TOKEN (stale DPF_MCP_TOKEN survives only in the gitignored local .mcp.json).
• Grok Build (xAI): GA CLI launched 2026-05-25; reads .claude/ directly (CLAUDE.md, marketplaces, skills, MCP) but exposes GROK_PLUGIN_ROOT (the hook seam above).

2026-07-24 refresh (BI-14E9F7CE closeout — Grok hook portability)

Reconciles the “Functional proof on Codex/Grok still pending” line above (2026-06-26 refresh) with work that landed in between and was not cross-referenced back to this tracker:

• The GROK_PLUGIN_ROOT vs CLAUDE_PLUGIN_ROOT seam named above turned out to be moot for actual enforcement. BI-883FC2FC live-probed real Grok 0.2.87 / Codex 0.142.x sessions and found the deeper root cause: Grok’s hook-execution plane ignores the plugin-bundled hooks/hooks.json entirely (a plugin shows has_hooks=true in grok inspect yet contributes total_hooks=0 — confirmed live, not inferred). So whether ${CLAUDE_PLUGIN_ROOT} resolves inside that file never mattered for Grok’s guard enforcement; the token is inert there either way. The actual delivery path Grok honors is a global ~/.grok/hooks/dpf-guards.json, written by packages/dpf-skill-pack/scripts/update_agent_toolchain.py::install_grok_hooks with fully pre-resolved absolute paths baked in by the Python installer at install time — no runtime env-var substitution involved at all. Codex is analogous: ~/.codex/hooks.json via install_codex_hooks, gated by Codex’s own interactive hook-trust step (tracked separately, BI-66EBEA06 — out of this BI’s scope).
• Static trace could not confirm the shared hooks/hooks.json’s ${CLAUDE_PLUGIN_ROOT} substitution mechanics are safe to alter. Official Claude Code docs (fetched 2026-07-24) confirm ${CLAUDE_PLUGIN_ROOT} is substituted as literal host-side text before a shell ever sees it (shell-agnostic today); wrapping it in POSIX fallback syntax (${CLAUDE_PLUGIN_ROOT:-$GROK_PLUGIN_ROOT}) would force that resolution to depend on the downstream shell instead — an unverifiable regression risk on Windows Claude Code installs (DPF’s own run-hook.mjs comment asserts Windows hooks run under PowerShell, not Git Bash, which cannot be confirmed live without a session restart). No change was made to hooks/hooks.json for this reason, matching the same judgment call PR #2455 made for this BI’s first slice.
• What DID land (BI-14E9F7CE, this refresh): a drift guard (packages/dpf-skill-pack/scripts/update_agent_toolchain_test.py::GrokCodexGuardSyncTest) asserting GROK_HOOK_GUARDS / CODEX_BASH_GUARDS / CODEX_ASK_GUARDS / CODEX_WRITE_GUARDS can never silently diverge from hooks/hooks.json’s actual blocking guards (classified by emitDeny( usage) — closing the realistic version of “guard hooks may silently not fire”: a future blocking guard added to hooks.json without a matching addition to those hand-maintained tuples.
• The drift guard proved itself (BI-0B292D84, 2026-08-26). Adding workroom-claim-guard.mjs to hooks/hooks.json alone left it wired for Claude and invisible to Codex and Grok; GrokCodexGuardSyncTest failed three assertions until the guard was added to GROK_HOOK_GUARDS, GROK_PRETOOLUSE_GROUPS, CODEX_BASH_GUARDS and CODEX_WRITE_GUARDS, plus a HOOK_PURPOSES entry. This is the first new blocking guard since the drift guard landed, and it caught exactly the failure it was written for. Two of its own assertions did have to change: they compared the wired-hook count against len(GROK_HOOK_GUARDS), which held only while every guard sat in exactly one matcher group. workroom-claim-guard.mjs is wired on both the shell and the write matcher (as hooks.json wires it for Claude), so those assertions now derive the expected count from GROK_PRETOOLUSE_GROUPS. The matchers are disjoint, so a guard in two groups still fires at most once per call.
• What remains genuinely unverified: whether BI-883FC2FC’s live-probe findings (Grok 0.2.87, Codex 0.142.x) still hold on current client versions — these clients change weekly per this tracker’s own framing, and no live Grok/Codex session was exercised in this pass (static trace + prior evidence only). Re-verify at the next monthly refresh.
• MCP token var: re-confirmed clean — no active setup snippet references bare DPF_MCP_TOKEN; the one surviving reference (e2e/fixtures/evidence.ts) is a deliberate DPF_MCP_BEARER_TOKEN ?? DPF_MCP_TOKEN back-compat fallback landed by PR #2455, not drift.

Refresh ritual — operationalization (BI-4B8EABF8 follow-up). The monthly ritual below is documented; wiring it as an actual scheduledAgentTask on the existing agent-task-scheduler.ts / agent-task-dispatch.ts substrate (read official docs → diff this tracker → file a BI per material drift → record sources + verification age) is the remaining code slice. No new cron — reuse the cognitive-load-migration scan substrate.

Governance outcomes (G1–G9) — multi-client parity

Spec: docs/superpowers/specs/2026-07-26-multi-client-governance-parity-design.md
Plan: docs/superpowers/plans/2026-07-26-multi-client-governance-parity.md
Last verified (live install sample): 2026-07-26. Outcomes are required; mechanisms may differ per client (thin adapters).

Backlog (filed 2026-07-26): BI-F4A1A0DC (docs/matrix), BI-BCA23DBB (Grok host plane + competitive), BI-C5F9A232 (BS Grok seed), BI-42FA7DD8 (worktree Tier-A reap), BI-A4BEFE99 (remaining clients equalize), BI-8BD61C30 (BS sandbox GC). Waves 0–3 implementation shipped via PRs #3594–#3601 + this branch.

Suggested-client adapter checklist (OpenCode / Gemini / Cursor)

Promote a suggested client only after each gate has evidence (or an explicit “comply by construction” note):

1. G1 Skills — install path for dpf-platform skills (plugin / skills dir / seed).
2. G2 Competitive — non-destructive disable of process-spine-replacements.json competitive ids.
3. G3 Plane-1 hooks — lease / root-clone / compose deny, or documented substitute.
4. G4 Session — SessionStart/End plane where the client exposes events.
5. G5 MCP — token env + snippet format.
6. G6 Workroom — external executor kind + evidence attribution.
7. G7 Worktree — canonical sibling base + hygiene hooks when events exist.
8. G8 Headless — non-interactive still honors deny.
9. G9 Readiness — bootstrap or dispatch readiness observable.

Source checklist also lives in packages/dpf-skill-pack/README.md (adapter checklist section).

What this currently tells us (the open adoption gaps)

• Governance parity (2026-07-26): Waves 1–3 closed Grok host/BS seed, competitive disable on Codex/Grok/Claude, worktree Tier-A, and BS sandbox GC. Remaining: Antigravity disable+hooks proof, OpenCode/Gemini/Cursor product pull, Docker image reap (separate). Token economy rows below remain separate.
• R3 — deferred tools on /api/mcp/v1 (✅ server / ◐ host proof): Phase 2 shipped in PR #4112 and the 2026-08-08 conformance hardening adds initialize bootstrap guidance, shared natural-language intent resolution, structured recovery, and a four-profile protocol probe. Do not infer that a host honors list_changed; record that separately when observed live.
• R4 — code execution in the native loop (⬜): the single biggest local-window token lever; sandbox already exists.
• R6 — local prefix-KV cache (◐): confirm DMR/llama.cpp reuses the static prefix.
• ⚠️ prompt-cache TTL: re-confirm each refresh; the 5-minute default changes the break-even math for long sessions.

Refresh ritual (monthly — how this stays fresh)

Reuse existing substrate; no new cron, no new system:

1. Trigger. A monthly scheduledAgentTask (the agent-task-scheduler.ts / agent-task-dispatch.ts substrate already used by the cognitive-load-migration scan) dispatches the refresh to the Enterprise Architect persona on the 1st.
2. Method. For each client, read the official docs (the dpf-platform:claude-api skill rule applies — never answer from memory) and diff against this matrix. The claude-code-guide agent type and web research cover the non-Anthropic clients.
3. Output. Update the cells + Last verified dates here; for each new token-saver worth adopting or each regression/deprecation, file a backlog item (dpf-file-backlog-item) linked to the context-engineering epic, and update context-engineering-standards.md if a criterion shifts.
4. Graph projection (planned). Project the matrix as nodes/edges in the living-architecture-graph (EP-ARCH-GRAPH-LIVE) so staleness is queryable and the Parity Engine surfaces drift automatically — the durable home once R-graph wiring lands.

Related

• docs/architecture/context-engineering-standards.md — the criteria this keeps current.
• docs/superpowers/specs/2026-06-20-context-engineering-tool-efficiency-design.md — research + sources.
• docs/superpowers/specs/2026-06-16-living-architecture-graph-and-operational-bridge-design.md — the graph home for the projected tracker.