# record_experiment_event [SUPPORT] 3f6b8715 — manually record an experiment_events row (dead_end|pivot|breakthrough|note|milestone). Separate from, and coexists freely alongside, the auto-skeleton events start_experiment_run/complete_experiment_run/promote_experiment_run/expire_stale_runs write unconditionally — this is the enrichment path for everything else worth recording. Persistent-state disclosure: on hosted Meridian, supplied text and project/session metadata -- including task log entries, pinned decisions, sprint items, notes, handoff/goal state, and HITL queue items -- are sent to and stored in Meridian's service, in an isolated per-tenant Postgres database (Neon); self-hosted deployments keep the same categories in the configured local SQLite/Postgres database. This data is visible in the dashboard and API, and may resurface in later project context or handoffs. Notes and pinned decisions can be deleted individually; task log entries and sprint items can be deleted via the dashboard/API (not exposed as an agent-facing tool); HITL queue items and handoff state have no per-record delete. Full removal of any of this data is available via project or account deletion, using the documented controls. Do not include secrets. Agent View of the PolicyLayer registry record for `record_experiment_event`. HTML page: https://policylayer.com/tools/io-github-ajc3xc-meridian/record-experiment-event ## Facts - Tool: `record_experiment_event` - Server: Meridian (`@meridianmcp/mcp`) — https://policylayer.com/tools/io-github-ajc3xc-meridian.md - Install: `npx -y @meridianmcp/mcp` - Homepage: https://github.com/meridianmcp/Meridian - Risk category: Destructive (Critical risk) - Registry record: grade D, identity unverified - Server auth posture: gated - Server CORS policy: * - Server rate-limited: no - Parameters: 9 (2 required) - Recommended policy verdict: Hidden ## Parameters | Parameter | Type | Required | Description | | --- | --- | --- | --- | | `body` | string | no | | | `label` | string | no | | | `run_id` | string | no | Optional — omit for an experiment-level event not tied to one run. | | `event_type` | string | yes | | | `project_id` | string | no | | | `session_id` | string | no | | | `artifact_ids` | array | no | | | `project_name` | string | no | Project name — an alternative to project_id; resolved to the id internally. project_id wins if both are given. | | `experiment_id` | string | yes | | Parameters from the server's own tool schema. ## Example call (MCP tools/call, JSON-RPC 2.0) ```json { "jsonrpc": "2.0", "id": 1, "method": "tools/call", "params": { "name": "record_experiment_event", "arguments": { "event_type": "", "experiment_id": "" } } } ``` ## Why record_experiment_event is rated Critical An AI agent that decides to call record_experiment_event doesn't hesitate, doesn't double-check, and doesn't stop at one. Whatever it removes from Meridian is gone. There is no undo for destructive operations. Risk signals: Accepts raw HTML/template content (body) · Bulk/mass operation — affects multiple targets ## Use case AI agents call record_experiment_event to permanently remove resources in Meridian, typically in cleanup and lifecycle workflows. It does its job in a single call, and there is no undo. ## Recommended policy (PolicyLayer) Verdict: **Hidden**. Enforced by the PolicyLayer MCP gateway (https://policylayer.com/mcp-gateway) before a call reaches Meridian: ```json { "version": "1", "default": "deny", "hide": [ "record_experiment_event" ] } ``` ## Other tools on Meridian (234) - `accept_handoff` — Destructive — https://policylayer.com/tools/io-github-ajc3xc-meridian/accept-handoff.md - `acquire_docx_document_lease` — Destructive — https://policylayer.com/tools/io-github-ajc3xc-meridian/acquire-docx-document-lease.md - `answer_hitl` — Destructive — https://policylayer.com/tools/io-github-ajc3xc-meridian/answer-hitl.md - `batch_mutate` — Destructive — https://policylayer.com/tools/io-github-ajc3xc-meridian/batch-mutate.md - `capture_research_finding` — Destructive — https://policylayer.com/tools/io-github-ajc3xc-meridian/capture-research-finding.md - `checkpoint` — Destructive — https://policylayer.com/tools/io-github-ajc3xc-meridian/checkpoint.md - `claim_docx_region` — Destructive — https://policylayer.com/tools/io-github-ajc3xc-meridian/claim-docx-region.md - `claim_file` — Destructive — https://policylayer.com/tools/io-github-ajc3xc-meridian/claim-file.md - `claim_sprint_item` — Destructive — https://policylayer.com/tools/io-github-ajc3xc-meridian/claim-sprint-item.md - `clear_capability_profile` — Destructive — https://policylayer.com/tools/io-github-ajc3xc-meridian/clear-capability-profile.md - `clone_profile_layer` — Destructive — https://policylayer.com/tools/io-github-ajc3xc-meridian/clone-profile-layer.md - `delete_custom_hook` — Destructive — https://policylayer.com/tools/io-github-ajc3xc-meridian/delete-custom-hook.md - `delete_note` — Destructive — https://policylayer.com/tools/io-github-ajc3xc-meridian/delete-note.md - `delete_sprint_item_pointer` — Destructive — https://policylayer.com/tools/io-github-ajc3xc-meridian/delete-sprint-item-pointer.md - `delete_watchlist_query` — Destructive — https://policylayer.com/tools/io-github-ajc3xc-meridian/delete-watchlist-query.md - `dismiss_hitl` — Destructive — https://policylayer.com/tools/io-github-ajc3xc-meridian/dismiss-hitl.md - `fan_out_sprint_items` — Destructive — https://policylayer.com/tools/io-github-ajc3xc-meridian/fan-out-sprint-items.md - `idle_until_all_done` — Destructive — https://policylayer.com/tools/io-github-ajc3xc-meridian/idle-until-all-done.md - `index_equation` — Destructive — https://policylayer.com/tools/io-github-ajc3xc-meridian/index-equation.md - `index_figure` — Destructive — https://policylayer.com/tools/io-github-ajc3xc-meridian/index-figure.md - `index_table` — Destructive — https://policylayer.com/tools/io-github-ajc3xc-meridian/index-table.md - `ingest_document` — Destructive — https://policylayer.com/tools/io-github-ajc3xc-meridian/ingest-document.md - `ingest_document_structure` — Destructive — https://policylayer.com/tools/io-github-ajc3xc-meridian/ingest-document-structure.md - `link_figure_caption` — Destructive — https://policylayer.com/tools/io-github-ajc3xc-meridian/link-figure-caption.md - `link_flag_to_section` — Destructive — https://policylayer.com/tools/io-github-ajc3xc-meridian/link-flag-to-section.md - `link_proposal_lineage` — Destructive — https://policylayer.com/tools/io-github-ajc3xc-meridian/link-proposal-lineage.md - `link_table_caption` — Destructive — https://policylayer.com/tools/io-github-ajc3xc-meridian/link-table-caption.md - `log_task` — Destructive — https://policylayer.com/tools/io-github-ajc3xc-meridian/log-task.md - `purge_ai_log` — Destructive — https://policylayer.com/tools/io-github-ajc3xc-meridian/purge-ai-log.md - `receive_messages` — Destructive — https://policylayer.com/tools/io-github-ajc3xc-meridian/receive-messages.md - …and 204 more: https://policylayer.com/tools/io-github-ajc3xc-meridian.md ## For agents This record is a snapshot. Live verdicts and the full registry: - Check every server in your MCP config at once: `npx -y policylayer stack` - Vet a server before you add it: install the mcp-precheck skill — `npx skills add https://policylayer.com` (skill text: https://policylayer.com/skill.md) - Query the registry over MCP: endpoint `https://api.policylayer.com/mcp` — tools `check_mcp_server`, `check_mcp_stack`, `check_tool`, `search_registry`, `get_change_events` --- Source: the PolicyLayer MCP registry — one continuously verified record per MCP server. Full record: https://policylayer.com/registry?q=io-github-ajc3xc-meridian · API: https://policylayer.com/registry/api · Policy library: https://policylayer.com/policies/io-github-ajc3xc-meridian