# query_as_of

Query relations valid at a specific point in time. Returns only relations where validFrom <= date AND (validUntil is undefined OR validUntil >= date). Time-travel query for temporal knowledge graphs.

Agent View of the PolicyLayer registry record for `query_as_of`. HTML page: https://policylayer.com/tools/danielsimonjr-memory-mcp/query-as-of

## Facts

- Tool: `query_as_of`
- Server: Enhanced Knowledge Graph Memory Server (`danielsimonjr/memory-mcp`) — https://policylayer.com/tools/danielsimonjr-memory-mcp.md
- Homepage: https://github.com/danielsimonjr/memory-mcp
- Risk category: Read (Low risk)
- Registry record: grade F, identity unverified
- Server rate-limited: no
- Parameters: 0
- Recommended policy verdict: Allowed

## Example call (MCP tools/call, JSON-RPC 2.0)

```json
{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/call",
  "params": {
    "name": "query_as_of",
    "arguments": {}
  }
}
```

## Why query_as_of is rated Low

This is a read-only retrieval operation on a temporal knowledge graph. It filters relations based on timestamp criteria but does not create, modify, delete, or execute any operations. The blast radius of misuse is minimal—an attacker gains historical data visibility but cannot alter state or trigger side effects.

From the tool's own definition: "Tool is named 'query_as_of' and explicitly described as a time-travel query that 'Returns only relations' from a knowledge graph. The description contains only read semantics: filtering and returning existing data with no modification, creation, or deletion."

## Use case

AI agents call query_as_of to retrieve information from Enhanced Knowledge Graph Memory Server without modifying anything. It is typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.

## Recommended policy (PolicyLayer)

Verdict: **Allowed**. Enforced by the PolicyLayer MCP gateway (https://policylayer.com/mcp-gateway) before a call reaches Enhanced Knowledge Graph Memory Server:

```json
{
  "version": "1",
  "default": "deny",
  "tools": {
    "query_as_of": {}
  }
}
```

## Other tools on Enhanced Knowledge Graph Memory Server (224)

- `adaptive_reduce_memories` — Destructive — https://policylayer.com/tools/danielsimonjr-memory-mcp/adaptive-reduce-memories.md
- `cache_clear` — Destructive — https://policylayer.com/tools/danielsimonjr-memory-mcp/cache-clear.md
- `clear_expired_memories` — Destructive — https://policylayer.com/tools/danielsimonjr-memory-mcp/clear-expired-memories.md
- `clear_heuristics` — Destructive — https://policylayer.com/tools/danielsimonjr-memory-mcp/clear-heuristics.md
- `clear_project_context` — Destructive — https://policylayer.com/tools/danielsimonjr-memory-mcp/clear-project-context.md
- `delete_entities` — Destructive — https://policylayer.com/tools/danielsimonjr-memory-mcp/delete-entities.md
- `delete_observations` — Destructive — https://policylayer.com/tools/danielsimonjr-memory-mcp/delete-observations.md
- `delete_relations` — Destructive — https://policylayer.com/tools/danielsimonjr-memory-mcp/delete-relations.md
- `delete_saved_search` — Destructive — https://policylayer.com/tools/danielsimonjr-memory-mcp/delete-saved-search.md
- `deregister_ref` — Destructive — https://policylayer.com/tools/danielsimonjr-memory-mcp/deregister-ref.md
- `forget_memory` — Destructive — https://policylayer.com/tools/danielsimonjr-memory-mcp/forget-memory.md
- `forget_weak_memories` — Destructive — https://policylayer.com/tools/danielsimonjr-memory-mcp/forget-weak-memories.md
- `invalidate_entity` — Destructive — https://policylayer.com/tools/danielsimonjr-memory-mcp/invalidate-entity.md
- `rbac_revoke_role` — Destructive — https://policylayer.com/tools/danielsimonjr-memory-mcp/rbac-revoke-role.md
- `remove_exclusion_rule` — Destructive — https://policylayer.com/tools/danielsimonjr-memory-mcp/remove-exclusion-rule.md
- `remove_heuristic` — Destructive — https://policylayer.com/tools/danielsimonjr-memory-mcp/remove-heuristic.md
- `remove_project_command` — Destructive — https://policylayer.com/tools/danielsimonjr-memory-mcp/remove-project-command.md
- `remove_project_convention` — Destructive — https://policylayer.com/tools/danielsimonjr-memory-mcp/remove-project-convention.md
- `remove_project_fact` — Destructive — https://policylayer.com/tools/danielsimonjr-memory-mcp/remove-project-fact.md
- `remove_project_glossary_term` — Destructive — https://policylayer.com/tools/danielsimonjr-memory-mcp/remove-project-glossary-term.md
- `remove_tag_alias` — Destructive — https://policylayer.com/tools/danielsimonjr-memory-mcp/remove-tag-alias.md
- `remove_tool_affordance` — Destructive — https://policylayer.com/tools/danielsimonjr-memory-mcp/remove-tool-affordance.md
- `consolidate_session` — Execute — https://policylayer.com/tools/danielsimonjr-memory-mcp/consolidate-session.md
- `dream_run_now` — Execute — https://policylayer.com/tools/danielsimonjr-memory-mcp/dream-run-now.md
- `dream_start` — Execute — https://policylayer.com/tools/danielsimonjr-memory-mcp/dream-start.md
- `dream_stop` — Execute — https://policylayer.com/tools/danielsimonjr-memory-mcp/dream-stop.md
- `end_session` — Execute — https://policylayer.com/tools/danielsimonjr-memory-mcp/end-session.md
- `parse_adr_markdown` — Execute — https://policylayer.com/tools/danielsimonjr-memory-mcp/parse-adr-markdown.md
- `run_consolidation_now` — Execute — https://policylayer.com/tools/danielsimonjr-memory-mcp/run-consolidation-now.md
- `run_decay_cycle` — Execute — https://policylayer.com/tools/danielsimonjr-memory-mcp/run-decay-cycle.md
- …and 194 more: https://policylayer.com/tools/danielsimonjr-memory-mcp.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`

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Source: the PolicyLayer MCP registry — one continuously verified record per MCP server. Full record: https://policylayer.com/registry?q=danielsimonjr-memory-mcp · API: https://policylayer.com/registry/api · Policy library: https://policylayer.com/policies/danielsimonjr-memory-mcp