> ## Documentation Index
> Fetch the complete documentation index at: https://docs.agentsentinel.dev/llms.txt
> Use this file to discover all available pages before exploring further.

# Replay Hub

> Org-wide history of local-replay submissions from every SDK client.

The **Replay Hub** lives at `/replay` (top-level sidebar entry). It's the org-wide ledger of every local replay an SDK client has ever submitted via `POST /api/v1/replay/{run_id}/results` — useful for auditing replay coverage, spotting divergences across deployments, and tracking how much money replay has saved.

## Why local replay?

Re-running a recorded run through the platform would cost real LLM dollars. The SDK's `replay_mode(ledger_path=...)` instead executes the run **locally**, replaying recorded outputs from the run bundle. After the replay finishes, the SDK posts a summary — what was replayed, what diverged, how much was saved — to the platform. This page is where those summaries land.

## Layout

The page has three sections:

1. **Header** — title, total submission count, and a manual **Refresh** button.
2. **Stat tiles** (4) — Submissions, Actions Replayed, Divergences, Cost Saved.
3. **Submissions table** — most recent first, with columns:

| Column               | Description                                            |
| -------------------- | ------------------------------------------------------ |
| **Run ID**           | Original run that was replayed (links to the run page) |
| **Status**           | `success` / `partial` / `failed` — color-coded badge   |
| **Replayed / Total** | Actions replayed vs total in the bundle                |
| **Divergences**      | Count of comparisons where inputs or outputs differed  |
| **Saved**            | USD saved vs re-running through the platform           |
| **Submitted**        | Wall-clock timestamp                                   |

## Reading the stats

* **Cost Saved** sums `cost_savings` across all submissions — that's the dollar amount you've avoided by replaying locally instead of re-executing.
* **Divergences > 0** means the SDK observed a difference between recorded and replayed values. Common causes: timestamps in inputs, random seeds, UUIDs, time-dependent API responses. Click a row's run ID to investigate at the per-action level on the run page.
* **Status `partial`** means some actions replayed cleanly while others diverged.

## Underlying API

* `GET /api/v1/replay/history/?skip=&limit=` — paginated org-wide history (newest first; max 200 per page)
* `GET /api/v1/replay/history/{run_id}` — submissions for a specific run
* `POST /api/v1/replay/{run_id}/results` — what the SDK calls after `ReplayMode.__exit__`

## When to use this page

* **Audit replay adoption** — how many of your runs have been replayed locally? Are CI gates running replays as expected?
* **Catch determinism regressions** — a sudden uptick in divergences after a deploy is a signal your run inputs/outputs grew non-deterministic dependencies.
* **Quantify savings** — the Cost Saved tile is the headline number for replay's ROI.

## See also

* [SDK → Replay](/sdk/python/replay) — `replay_mode()` context manager
* [Console → Runs](/console/runs) — per-run detail and per-action divergence drill-down
* [Platform → Replay](/platform/replay) — full API reference (analysis, bundle download, evaluate)