Reasoning helpers

Both helpers are available on hosted HTTP MCP and stdio MCP. They retrieve prior context; they do not guarantee vector-only retrieval or generated analysis.

Tool	Use	Hosted output	Stdio output
What do I know	Scan a topic	Trimmed recall payload	Summary, returned count, first five memories
Why did we	Find decision evidence	Trimmed recall or explicit fallback payload	Retrieval label, decision memories, optional fallback memories

Results are bounded. Query named knowledge bases explicitly for reference material. Supply identity, conversation, and project context where supported. These settings partition an account; they do not create separate tenant security boundaries.

When to use

Start with What do I know when you need an overview for planning. Choose Why did we when you have a particular decision to investigate. Use recall for explicit mode/category control and search for transcript wording.

Parameters

Helper	Required input	Optional controls
`crystal_what_do_i_know`	`topic` (at least 3 characters on hosted MCP)	`limit` 1–20, stores, tags, conversation/identity/project context
`crystal_why_did_we`	`decision` (at least 3 characters on hosted MCP)	`limit` 1–20, conversation/identity/project context

Examples

Begin with a topic

Request body:

{
  "topic": "backup procedures",
  "limit": 5
}

Hosted MCP response (selected fields):

{
  "memories": [
    {
      "memoryId": "<memory-id>",
      "title": "Backup verification rule",
      "content": "Verify a backup before replacing the previous copy.",
      "store": "procedural",
      "category": "rule"
    }
  ],
  "messageMatches": [],
  "assetContexts": [],
  "degraded": false
}

Use the evidence

Read the returned records, separate recorded decisions from related context, and follow up with get memory or trace. The stdio title summary and reasoning label are presentation aids; they do not add facts to the source material.

Errors and common mistakes

A bounded scan cannot enumerate everything you know. Check scope and filters when results are empty, and query a named KB directly when that is the expected source. Do not present fallback context as proof of why a decision was made.

Tools Overview

Memory Lookup

Memory Writing

Session Continuity

Knowledge Bases

Diagnostics

Research

HTTP API

Reasoning helpers

When to use

Parameters

Examples

Begin with a topic

Use the evidence

Errors and common mistakes

​When to use

​Parameters

​Examples

​Begin with a topic

​Use the evidence

​Errors and common mistakes

When to use

Parameters

Examples

Begin with a topic

Use the evidence

Errors and common mistakes