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ChatCrystal

NPM · CHATCRYSTAL · SCANNED SEP 20

Local-first AI PKM memory for coding conversations.

Available components

0 this week 93 Trust /100
Trust breakdown (7 categories)

How this component scores in each security and reliability category. Every signal is checked automatically from public evidence about the published package, including repeated runs of it in an isolated sandbox, and we only credit what we can confirm. How we score → Why this is hard to score →

Supply Chain Security98
  • No malware found by supply-chain analysis.Pass
  • No known CVEs affecting this package version or its production dependencies.Pass
  • No install/post-install scripts declared.Pass
  • 83 of 296 dependencies flagged as unhealthy (1 deprecated). View diagnostics → Partial
Provenance & Transparency100
  • Source repository is publicly reachable at the declared URL. View diagnostics → Pass
  • Cryptographically verified build provenance (signed, bound to ZengLiangYi/ChatCrystal). View diagnostics → Pass
  • Clear OSI-approved license (Apache-2.0).Pass
  • Actively maintained (last published 0 days ago).Pass
  • Publishes a security disclosure policy (SECURITY.md).Pass
Schema Quality & AI Usability76
  • AI-judged instruction clarity (excellent).Pass
  • Context-footprint check failed: tool/resource definitions use about 858 tokens (~122/item across 7 items; 7 tools + 0 resources), over budget; trim descriptions and params. See how to fix → Fail
  • Usage-examples check failed: none of the tools include examples. See how to fix → Fail
Stability & Change Management87
  • Stability observed for 26 of 30 days with no destabilising changes; credit accrues until the full window elapses.Partial
Tool Coverage100
  • 100% of tools have a non-trivial description (not blank, and not just the tool's name).Pass
  • 100% of tool parameters carry a description.Pass
Tool Safety100
  • No prompt-injection markers were found in the server instructions, tool names or descriptions we captured.Pass
  • We read all 7 captured tool definition(s), and no name or description among them implies an irreversible operation.Pass
  • An AI judge read all 7 captured unit(s) of tool text and found none that tries to manipulate the model reading it.Pass
Capabilities100
  • Implements a supported MCP spec version (2025-11-25); the latest is 2026-07-28.Pass
Install

How do I install the ChatCrystal MCP server?

ChatCrystal runs locally as an npm package, launched with npx -y chatcrystal. Ready-made configuration for Claude, Cursor, VS Code, Codex and 5 more is on this page, copied from each client's own documentation.

npm · chatcrystal

# add to Claude Code
claude mcp add zengliangyi-chatcrystal -- npx -y chatcrystal
// .cursor/mcp.json
{
  "mcpServers": {
    "zengliangyi-chatcrystal": {
      "command": "npx",
      "args": [
        "-y",
        "chatcrystal"
      ]
    }
  }
}
// .vscode/mcp.json
{
  "servers": {
    "zengliangyi-chatcrystal": {
      "command": "npx",
      "args": [
        "-y",
        "chatcrystal"
      ]
    }
  }
}
# add to Codex CLI
codex mcp add zengliangyi-chatcrystal -- npx -y chatcrystal
// opencode.json
{
  "$schema": "https://opencode.ai/config.json",
  "mcp": {
    "zengliangyi-chatcrystal": {
      "type": "local",
      "command": [
        "npx",
        "-y",
        "chatcrystal"
      ],
      "enabled": true
    }
  }
}
# add to OpenClaw
openclaw mcp add zengliangyi-chatcrystal --command npx --arg -y --arg chatcrystal
# ~/.hermes/config.yaml
mcp_servers:
  zengliangyi-chatcrystal:
    command: "npx"
    args: ["-y", "chatcrystal"]
// ~/.netclaw/config/netclaw.json
{
  "McpServers": {
    "zengliangyi-chatcrystal": {
      "Transport": "stdio",
      "Command": "npx",
      "Arguments": [
        "-y",
        "chatcrystal"
      ]
    }
  }
}
# add to Vellum
assistant mcp add zengliangyi-chatcrystal -t stdio -c npx -a -y chatcrystal
// mcp.json
{
  "mcpServers": {
    "zengliangyi-chatcrystal": {
      "command": "npx",
      "args": [
        "-y",
        "chatcrystal"
      ]
    }
  }
}
Changelog

Every change we have recorded for this component, newest first. Security-relevant changes are always shown. ▲ marks a change for the better, ▼ a change for the worse; unmarked changes are neutral.

  • 20 Sept 26 0
    • Stability: 0.83 → unverified security
    • Tool safety: pass → unverified security
    • Capabilities: pass → unverified functional
    • Tool coverage: 100 → unverified functional
    • Schema quality: Schema quality not yet verified: we do not have a sandbox capture of the MCP schema this version of the package serves yet. functional
    • Package version: 0.6.0 → 0.6.1 functional
  • 19 Sept 26 +1

    No change was recorded against any check on this day. Stability & Change Management went from 80 to 83. That category is still filling its 30-day observation window: 24 days of observed history at the previous scan, 25 at this one. The score rises as the window fills, whether or not the server changes.

  • 18 Sept 26 −3
    • Stability: pass → 0.80 functional
  • 17 Sept 26 0
    • Stability: 0.97 → pass security
  • 16 Sept 26 +1

    No change was recorded against any check on this day. Stability & Change Management went from 93 to 97. That category is still filling its 30-day observation window: 28 days of observed history at the previous scan, 29 at this one. The score rises as the window fills, whether or not the server changes.

  • 14 Sept 26 +1

    No change was recorded against any check on this day. Stability & Change Management went from 87 to 90. That category is still filling its 30-day observation window: 26 days of observed history at the previous scan, 27 at this one. The score rises as the window fills, whether or not the server changes.

  • 12 Sept 26 −2
    • Stability: pass → 0.83 functional
  • 11 Sept 26 0
    • Stability: 0.97 → pass security
Diagnostics

Diagnostic detail from the automated scan of this channel: what the scanner observed at each step, so you can see exactly where a check passed or failed. It is informational only and never changes the trust score.

Captured 20 Sept 2026 · Analysed npm/chatcrystal@0.6.1

Provenance Verified

A signed build attestation was found and verified, binding this exact artifact to the source repository it claims to come from.

Result Verified
Ecosystem npm
Reason Verified
Discovered via Registry attestation endpoint
Source repo ZengLiangYi/ChatCrystal
Certificate issuer https://token.actions.githubusercontent.com
Certificate SAN https://github.com/ZengLiangYi/ChatCrystal/.github/workflows/release.yml@refs/tags/v0.6.1
Rekor log index 2899512889
Predicate type https://slsa.dev/provenance/v1
Subject digest sha512:86c3a0ddf046b34d608d5765a0df6d33958cd10ecfc7178fc35a2444a3b9ab493b1a55ed4acf857c24229045a86f2792a016e2e20cbd0ff73cc69fc7c

Background: How many MCP packages publish verified provenance →

Dependencies 296 packages
Packages resolved 296
Deprecated 1
Stale 83
Tree resolution Complete

Background: SBOMs and build attestations, explained →

MCP tools · 7 exposed · ~858 tokens

The tools this component advertises to a client, with an estimated token cost for each. Expand a tool to see its parameters and schema. The per-tool counts are indicative and are not scored directly; the schema's total context footprint is one signal in Schema Quality & AI Usability. A tool's description is untrusted text the model reads on every call, which is what makes this list a security surface and not just an inventory: how tool poisoning works →

Tool Tokens
get_note ~38

Get the full content of a note including title, summary, key conclusions, code snippets, and tags.

NameTypeReqDescription
idnumberyesNote ID

No output schema declared.

No examples provided.

get_relations ~38

Get related notes for a given note, including relationship type and confidence score.

NameTypeReqDescription
noteIdnumberyesNote ID to find relations for

No output schema declared.

No examples provided.

list_notes ~145

List note summaries for browsing and narrowing the ChatCrystal knowledge base. Use this when you need paginated notes filtered by tag or title/summary keyword. Use search_knowledge instead for semantic relevance ranking, and get_note when you already have an id and need the full note body. Returns note metadata and summaries, not full note content.

NameTypeReqDescription
pagenumber1-based page number for paginated note summaries. Each page returns up to 20 notes.
searchstringLiteral keyword filter applied to note title and summary; not semantic search.
tagstringExact tag name to filter notes by, for example "mcp" or "cursor".

No output schema declared.

No examples provided.

recall_for_task ~183

Retrieve reusable task memories before starting substantive coding work. Use this at the beginning of implementation, debugging, migration, configuration, investigation, refactor, or optimization tasks to load project-scoped memories first and optional global lessons second. Use mode="debug" when the user reports an error, failing command, regression, or incident; include error_signatures and related_files when available. Use search_knowledge instead for ad hoc semantic note search that is not tied to the current task. This tool is read-only and returns ranked memories plus optional related-note context without writing anything.

NameTypeReqDescription
modestringUse task for normal work and debug when the task starts from an error, failing test, or incident.
optionsobjectOptional limits and relation expansion controls for recall results.
taskobjectyesCurrent task context used to retrieve relevant project and global memories.

No output schema declared.

No examples provided.

search_knowledge ~46

Semantic search across your AI conversation knowledge base. Returns matching notes ranked by relevance.

NameTypeReqDescription
limitnumberMaximum number of results
querystringyesSearch query text

No output schema declared.

No examples provided.

validate_task_memory ~204

Dry-run validation for a candidate task memory before calling write_task_memory. Use this after meaningful work and before persisting a lesson to check whether the candidate is durable, specific, reusable, and shaped like a high-quality ChatCrystal note. It has no side effects and never writes to the knowledge base. Returns acceptance, rejection reason, warnings, and materialized note fields so agents can revise the candidate or skip weak work logs.

NameTypeReqDescription
memoryobjectyesCandidate ChatCrystal note content to validate or persist as reusable task memory.
modestringyesUse auto for agent-generated writebacks and manual for explicit user-curated memories.
scopestringStore as project memory by default; global is reserved for broadly reusable manual lessons.
source_run_keystringIdempotency key for auto writebacks; required in auto mode to avoid duplicate memory receipts.
taskobjectyesCurrent task context used to scope, rank, and store memories.

No output schema declared.

No examples provided.

write_task_memory ~204

Persist a task memory only when it can become a high-quality ChatCrystal note: specific title, concrete summary, meaningful key conclusions, and a durable reusable lesson such as a pitfall, fix, decision, pattern, or symptom-to-resolution mapping. Do not write one-time environment checks, version/status reports, ordinary progress logs, or vague robustness claims. Weak auto writebacks are skipped by core validation and recorded only as receipts.

NameTypeReqDescription
memoryobjectyesCandidate ChatCrystal note content to validate or persist as reusable task memory.
modestringyesUse auto for agent-generated writebacks and manual for explicit user-curated memories.
scopestringStore as project memory by default; global is reserved for broadly reusable manual lessons.
source_run_keystringIdempotency key for auto writebacks; required in auto mode to avoid duplicate memory receipts.
taskobjectyesCurrent task context used to scope, rank, and store memories.

No output schema declared.

No examples provided.

Common questions

What is the ChatCrystal MCP server?

ChatCrystal is an MCP server listed in the public MCP registry as io.github.ZengLiangYi/chatcrystal. Local-first AI PKM memory for coding conversations. This page covers its npm package (chatcrystal).

Is the ChatCrystal MCP server safe to use?

ChatCrystal scores 93 out of 100 on VerifyMCP. We found no known CVEs affecting it as of 20 September 2026. It declares no install or post-install scripts. Its build provenance is signed and verified. That is a record of what we were able to check automatically, not an endorsement. The category breakdown on this page shows every signal behind the number, including the ones we could not confirm.

What tools does the ChatCrystal MCP server expose?

ChatCrystal exposes 7 tools: search_knowledge, get_note, list_notes, get_relations, recall_for_task, and 2 more. Their descriptions and schemas cost roughly 858 tokens of context every time the server is loaded.

Is the ChatCrystal MCP server still maintained?

ChatCrystal is still listed as active in the MCP registry. We last reached this channel on 20 September 2026. Those dates come from our own scans of the registry and the channel itself, not from anything the publisher announced.

What licence is the ChatCrystal MCP server under?

ChatCrystal declares the Apache-2.0 licence, which is OSI-approved. That covers the source only, and says nothing about the cost of any service it calls.