[Harrilee]

Summary

Part of ai-dynamo/aisimulate#38 (AgentX public replay, routing, and lifecycle support).

Enable AgentX G2 through Dynamo's canonical engine configuration and typed replay APIs: offline vLLM, one aggregated worker or 1P1D, attention DP=1, static pools, and speculation disabled. G3 and approximate speculative decode speedup are rejected for AgentX G2; HBM-only speculation and ordinary-trace topology support remain available.

These restrictions define the qualified AgentX support boundary, not a demonstrated limitation of the native G2 engine. A Dynamo trace carrying agent_context uses the agentic driver and is subject to the same guard even without agentic_lanes; captured multiworker agentic traces with G2 are therefore rejected. Ordinary non-agentic traces retain their existing topology support.

Forward snapshot, warmup, and profile controls while preserving source clocks, lanes, warmup caches, and report metadata. Preserve finite AgenticMooncake timing and host-tier routing; only Device stores establish P/D handoff residency. Shared-layout identity uses resolved physical cache geometry, independently of P/D transfer size.

Integration with main

Merged current main, including #15647 and #15673. Engine lowering and validation use AISimulate's public materialize_engine_launch_config and Rust MockerConfig. The removed MockEngineArgs and private layout-helper dependency are not restored. AgentX guards, lifecycle forwarding, and integration tests now use the canonical contract; the native AgentX entrypoints explicitly reject G3.

Python/Rust dependencies and all three Cargo lockfiles use published AISimulate nightly 67 (0.13.0.dev202610060000000067 / 0.13.0-dev.202610060000000067), including ai-dynamo/aisimulate#381. No additional AISimulate change or stacked PR is required.

General image builds use main’s default remote-worker routing, including #15814’s expanded worker discovery. The temporary fresh_builder overrides are removed after the Kubernetes builder transport failed with TLS errors on all four targets. Reconnects still preserve shared daemons and cleanup waits for all consumers. Builder names pass through environment variables and quoted Docker arguments in both bootstrap and refresher actions. Existing test selection and timeout budgets are retained.

Validation

On the merged tree, rebuilt and installed the native runtime wheel against nightly 67:

• 260 native mocker tests and 127 Python tests passed, including real G2 restores/lifecycle controls, canonical configuration/geometry checks, offline/online timing equivalence, and native AgentX G3 rejection.
• Both CI mypy commands, Clippy with warnings denied, Rust formatting, and changed-file pre-commit passed.
• Docs lint and Fern configuration checks passed. The full-site link scan still reports one unchanged DeepSeek recipe link present on main.

Earlier CI/security fixes are retained unchanged: full hosted CI passed on 3f5f5460ad; CodeQL Actions passed on f1e26141ed with zero findings and confirmed alert #827 fixed. Hosted checks for this merge commit must run independently.

Qualification remains functional_only; no hardware/Mooncake performance equivalence is claimed.

Summary by CodeRabbit

• New Features
  • Offline agentic trace replay now supports snapshot sampling, warmup, and profiling controls.
  • Shared host-offload layouts can be configured with resolved engine block sizes and cache-byte settings.
  • Replay reports include agentic graph, projection, snapshot, phase, and profile details when available.
• Bug Fixes
  • Agentic Mooncake replay timing is normalized more consistently across replay modes.
  • Host-tier KV events no longer count as evidence of GPU handoff residency.
• Documentation
  • Expanded replay guidance for AgentX host offload, trace formats, topology, and report fields.

[devin-ai-integration]

✅ Dynamo PR CI passed — run 37706756377 (attempt 2) on dedc8b862d

Gate checks: ✅ backend-status-check · ✅ deploy-status-check · ✅ dynamo-status-check

_{Posted automatically by Devin for run 37706756377. Updated on every full-CI run of this PR.}

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[github-actions]

🌿 Fern Docs Preview: https://nvidia-preview-01a11daa-1a91-7460-809e-b7790e5ce45c.docs.buildwithfern.com/dynamo/dev

[coderabbitai]

Walkthrough

The replay changes add agentic snapshot, warmup, and profiling options, plus shared host-offload layout resolution and execution checks. They update replay metadata, trace handling, and documentation, and add configuration and end-to-end qualification tests.

Changes

Agentic replay and G2 host offload

Layer / File(s)	Summary
Shared host-offload layout configuration components/src/dynamo/replay/config.py, components/src/dynamo/mocker/tests/unit/test_config.py, components/src/dynamo/replay/tests/test_simulation.py, tests/dependencies/test_aisimulate_namespaces.py, docs/fern/pages/reference/components/dynosim-replay-cli-reference.mdx, dependency manifests	Lowering merges nested rank configuration, resolves shared-layout geometry, and derives layout IDs. It keeps cache bytes per token distinct from transfer bytes. Tests cover geometry resolution, aliases, invalid values, and the layout helper. AISimulate pins are updated.
Agentic replay phase options lib/mocker/src/replay/agentic.rs, lib/mocker/src/replay/{entrypoints.rs,mod.rs}, lib/mocker/src/replay/offline/entrypoints.rs, lib/bindings/python/rust/llm/replay.rs, lib/bindings/python/src/dynamo/_core.pyi, components/src/dynamo/replay/{api.py,simulation.py}, lib/bindings/python/tests/replay/test_replay_agentic_timing.py, CLI reference	Replay APIs accept snapshot, warmup, and profile options. Native code validates the options and builds replay drivers. Offline aggregated and disaggregated paths pass the options through; timing tests cover online and offline replay.
Host-offload execution checks and KV events lib/mocker/src/replay/offline/entrypoints.rs, lib/mocker/src/replay/entrypoints.rs, lib/mocker/src/replay/offline/extensions/kv_events/mod.rs, components/src/dynamo/replay/simulation.py, components/src/dynamo/replay/tests/test_simulation.py	Agentic host offload is checked for worker count, scaling, engine type, DP settings, and speculative decoding. Online agentic host offload returns an error. Stored hashes count GPU-tier stores; host-tier events remain available to KV ingest. Tests cover the checks and event behavior.
Replay integration, reports, and qualification components/src/dynamo/replay/simulation.py, components/src/dynamo/replay/tests/test_agentx_g2.py, components/src/dynamo/replay/tests/test_simulation.py, CLI reference	Replay target-model lookup and metadata normalization handle additional agentic fields. Qualification tests cover trace formats, host-cache reuse, shared pools, resumption, warmup, profiling, and incomplete restores. Documentation describes trace constraints, supported topology, and report fields.

Priority: ➖ Normal

Estimated code review effort: 4 (Complex) | ~60 minutes

Merge Risk: 🔵 Low · up to 428da

Shared-pool layout identity may differ from the selected engine when its type is omitted. Confirm that configuration before relying on automatic layout derivation; the available evidence does not establish a broader replay failure.

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 38.75% which is insufficient. The required threshold is 80.00%. Docstring coverage is scoped to functions touched by this diff. Analyzed 80 functions across 15 files. (6 skipped:…	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Title check	✅ Passed	The title clearly identifies the main change: qualifying AgentX G2 through existing replay APIs.
Description check	✅ Passed	The description is detailed and covers the change scope, implementation details, reviewer-relevant constraints, validation, and issue context through ai-dynamo/aisimulate#38. It does not use every tem…

Full details: Docstring Coverage

Explanation

Docstring coverage is 38.75% which is insufficient. The required threshold is 80.00%. Docstring coverage is scoped to functions touched by this diff. Analyzed 80 functions across 15 files. (6 skipped: 6 unsupported.)

• Fix all pre-merge checks with AI

✨ Finishing Touches 💡 1

🛠️ Fix failing CI checks 💡

• Commit to this branch
• Create a new PR

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[coderabbitai]

Actionable comments posted: 1

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• 🪄 Fix CodeRabbit comments on this PR

🤖 Prompt to fix review comments

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Inline comments:
Review comments at @components/src/dynamo/replay/config.py:
- Line 181: Update the backend fallback in the `raw.get("engine_type", ...)`
assignment to use the `MockEngineArgs` default engine type rather than
`identity["backend"]`, keeping the resolved layout geometry consistent when
`engine_type` is omitted.

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📥 Commits

Reviewing files that changed from the base of the PR and between c746b5d and 428da55.

⛔ Files ignored due to path filters (3)

• Cargo.lock is excluded by !**/*.lock
• lib/bindings/kvbm/Cargo.lock is excluded by !**/*.lock
• lib/bindings/python/Cargo.lock is excluded by !**/*.lock

📒 Files selected for processing (21)

• Cargo.toml
• benchmarks/pyproject.toml
• components/src/dynamo/mocker/tests/unit/test_config.py
• components/src/dynamo/replay/api.py
• components/src/dynamo/replay/config.py
• components/src/dynamo/replay/simulation.py
• components/src/dynamo/replay/tests/test_agentx_g2.py
• components/src/dynamo/replay/tests/test_simulation.py
• container/deps/requirements.aisimulate.txt
• docs/fern/pages/reference/components/dynosim-replay-cli-reference.mdx
• lib/bindings/python/Cargo.toml
• lib/bindings/python/rust/llm/replay.rs
• lib/bindings/python/src/dynamo/_core.pyi
• lib/bindings/python/tests/replay/test_replay_agentic_timing.py
• lib/mocker/src/replay/agentic.rs
• lib/mocker/src/replay/entrypoints.rs
• lib/mocker/src/replay/mod.rs
• lib/mocker/src/replay/offline/entrypoints.rs
• lib/mocker/src/replay/offline/extensions/kv_events/mod.rs
• pyproject.toml
• tests/dependencies/test_aisimulate_namespaces.py

Included review availability: This review used your included allowance. Your plan provides up to 12 included reviews per hour; 11 remain after this review.

[dreamtalen]

Approving, with two comments below.

• AgentX + G2 limits in validate_agentic_host_offload. Is the restriction (one aggregated worker or 1P1D, attention DP=1, static pools, no speculative decoding, offline only) intentional because of a known AgentX-specific limitation? The underlying native G2 path already supports multiple workers, ADP>1, KV-router routing, and online replay. This guard also applies to plain Dynamo traces that carry agent_context, even without agentic_lanes. So replaying a captured trace with G2 on multiple workers now fails on the direct dynamo.replay path.

• Coordination with ai-dynamo/dynamo#15673. That PR (open, same AISimulate nightly 67) delegates engine-config lowering and validation to AISimulate:

  • it removes lower_upstream_engine_args;
  • it switches the runner to AISimulate's public materialize_engine_launch_config;
  • it replaces Rust MockEngineArgs with MockerConfig.

[PeaBrane]

✅

[dmitry-tokarev-nv]

No P0, P1 or P2 found at dedc8b862d8955b0702ffa7b89b42a072c46fcae. There are 3 P3 findings and 1 open item.

This review covers all 19 files at this head: the replay, mocker, binding, test and docs files, plus the CI files and container/deps/requirements.aisimulate.txt.

• [P3] The CI changes are not part of the replay feature, and main allows only squash merges. The squash commit will carry them under the feat(replay) title. Please list them in the squash commit message, or move them to a separate ci pull request.
• [P3] The docs edit removes a rule that the CLI still enforces. docs/fern/pages/reference/components/dynosim-replay-cli-reference.mdx:180-181. aisimulate predict --stack dynamo still rejects stop.max_virtual_time_seconds for agentic_mooncake and for weka. Please keep the clause "and reject the virtual-time cutoff".
• [P3] No test reads the new top-level report metadata. components/src/dynamo/replay/simulation.py:182, :544-550 and :552. Three changes that break these lines still pass every replay test (see the table below), because the AgentX G2 tests read the values from native_report only. Please assert agentic_snapshots, agentic_phases and agentic_profile in report.metadata in one snapshot test. Please also assert agentic_qualification for a dynamo trace that has agent_context and no agentic_lanes.
• Open item: two outdated threads are unresolved, at benchmarks/pyproject.toml:42 (a TODO from the author) and components/src/dynamo/replay/config.py:181 (CodeRabbit). Neither file is in the diff now. main requires resolved conversations, so these threads block the merge.

What was measured on the replay, mocker, binding, test and docs files.

1. Rust. cargo test --locked -p dynamo-mocker --no-default-features --lib passed 256 tests at the head and 246 tests on main (478a6876f5). The 10 extra tests are the new tests. Each of these six deliberate breaks of the new code failed at least one new test:

Deliberate break	Failing test
agentic.rs: speedup ratio replaced by 1.0	finite_workload_preserves_timestamps_and_scales_timers_once
agentic.rs: snapshot lanes capped to the play count	snapshot_sampling_keeps_source_clock_and_requested_lane_count
offline/entrypoints.rs: G3 check removed	native_execution_rejects_canonical_g3_for_agentic_replay
offline/entrypoints.rs: *workers == 1 changed to >= 1	rejects_unsupported_deployment_on_every_active_role, native_execution_entrypoints_apply_the_agentic_g2_guard
offline/entrypoints.rs: decode_speedup_ratio check removed	rejects_unsupported_deployment_on_every_active_role
kv_events/mod.rs: Device filter removed	g2_events_remain_routable_but_do_not_prove_gpu_handoff_residency

The Device filter is already on main. The new test pins it.

2. Bindings. The #[pyo3(signature)] of run_mocker_trace_replay and the full overload in _core.pyi have the same 37 parameters, in the same order, with the same defaults. The comparison finds a planted default change in a copy of the stub. I built _core from the head with maturin develop on Linux x86_64. test_replay_agentic_timing.py passed 8 of 8. The speedup moved from the binding into AgenticReplayOptions. With the binding changed to also apply arrival_speedup_ratio, the test failed 4 of 8. The rebuilt head passed 8 of 8 again.

3. Python. The tests ran with the pinned aisimulate==0.13.0.dev202610060000000067 and no network (docker run --network none). test_agentx_g2.py passed 28 of 28, and test_simulation.py passed 57 of 57. tests/dependencies/test_aisimulate_namespaces.py passed 4 of 4. Deliberate breaks of the new code:

Deliberate break	Result
simulation.py: **agentic_options removed from the aggregated call	11 test_agentx_g2.py tests fail
api.py: agentic_snapshot removed from the replay arguments	11 test_agentx_g2.py tests fail
simulation.py: timing-model lookup for the target model removed	2 test_simulation.py tests fail
simulation.py:544-550: snapshot, phase and profile keys not copied into metadata	no test fails
simulation.py:552: list values not copied	no test fails
simulation.py:182: "agentic_graph" in metadata removed	no test fails

A direct probe at the head shows that the promotion works. With snapshot, warmup and profile and no raw report, report.metadata has agentic_snapshots (a list), agentic_phases and agentic_profile. For the dynamo-agentic.jsonl fixture without agentic_lanes, it has agentic_qualification: functional_only. With the simulation.py:544-550 or the simulation.py:182 break in place, the same probe finds these keys missing.

The markers follow .ai/pytest-guidelines.md. The tests use fixture model names only, so .ai/test-model-size-guardrails.md does not apply.

Other probes at the head: an agentic_mooncake file with only a header fails with did not contain any requests, with or without the phase options, and does not panic. An unknown key in agentic_snapshot or agentic_profile fails with unknown field.

4. Docs. docs/fern/scripts/docs_lint.py reports 0 errors for the page, and a planted broken link fails it. Results of aisimulate predict --stack dynamo at the head, with no network:

Configuration	Result
agentic_mooncake, aggregated (control)	runs, 3 requests
agentic_mooncake, disaggregated	runs, 3 requests
kv_router, one aggregated worker	runs, 6 requests
kv_cache.host_offload with an unknown key	rejected with num_host_blocks Field required, so the field exists
mooncake-delta, aggregated (control)	runs, 2 requests
mooncake-delta, disaggregated	rejected: mooncake-delta requires aggregated engine mode
agentic_mooncake, concurrency load	rejected: agentic_mooncake requires trace_timestamps load
agentic_mooncake, stop.max_virtual_time_seconds: 100	rejected: agentic_mooncake does not support max_virtual_time_seconds
weka, no stop (control)	runs, 3 requests
weka, stop.max_virtual_time_seconds: 100	rejected: weka does not support max_virtual_time_seconds

The new Python API arguments and defaults on the page match api.py, replay.rs and _core.pyi.

5. Merge. git merge-tree --write-tree of the head with main at 478a6876f5 and at 689a20b491 gives no conflicts. main did not change any of the 19 files after the merge base 3213fe6f03.

6. CI at this head. All checks passed. PR run 37706756377 (attempt 2) ran the new tests. test / sequential cuda13.0, amd64 passed 28 of 28 test_agentx_g2.py tests and the new test_simulation.py cases. test / parallel cuda13.0, amd64 passed 8 of 8 test_replay_agentic_timing.py tests and the new namespace test. In attempt 1, DGDR Deploy Test / CPU / lifecycle failed with Cannot connect to host 127.0.0.1:8443 (the vCluster API), and it passed on the rerun. That failure does not relate to this diff.

What was measured on the CI files.

• The new quoted form reads --help and x; echo INJECTED-OLD as builder names. The old form read them as an option and as shell code. The probe used the buildx of the runner image.
• docker buildx rm --keep-daemon leaves the two builder Deployments in place. The clean-k8s-builder job removes them at the end of the run.
• All 24 needs ids of the cleanup job exist, and all 19 jobs that read builder_name are inside its needs closure.
• Each action and workflow that receives fresh_builder declares it as an input.
• actionlint and shellcheck give the same findings at the head and on main. None is on a changed line.
• In run 37706756377, the new inspect --bootstrap form ran in both actions and passed.

[dmitry-tokarev-nv]

LGTM. Few P3 findings by the agent in the comment on the PR.