CML Memory -- Cognitive Memory Layer for OpenClaw

Structured long-term memory powered by the Cognitive Memory Layer (CML) API. Store facts, preferences, constraints, and episodes across conversations.

When to Use This Skill

Activate this skill whenever you need to:

•Remember something the user told you (preferences, facts, personal details).
•Recall previously stored information before answering a question.
•Forget information the user asks you to remove.
•Track important events, decisions, or conversations over time.

This skill gives you persistent, structured memory that survives across sessions and conversations. Use it proactively -- store important information as soon as you learn it, and retrieve context before answering questions about the user.

Configuration

The following environment variables must be set (in your shell or OpenClaw config):

Variable	Required	Default	Description
`CML_BASE_URL`	Yes	`http://localhost:8000`	CML API server URL
`CML_API_KEY`	Yes	--	API key for authentication
`CML_TENANT_ID`	No	`openclaw`	Tenant partition for memories

Memory Types

Choose the correct type when storing memories. This affects how memories are consolidated and retrieved.

Type	When to Use	Examples
`semantic_fact`	Permanent, factual information about the user or world	"User's name is Alice", "User works at Acme Corp"
`preference`	User likes, dislikes, and preferred ways of doing things	"Prefers dark mode", "Likes concise answers"
`constraint`	Hard rules, restrictions, allergies, must-follow policies	"Allergic to peanuts", "Never schedule before 9am"
`episodic_event`	Specific events, meetings, decisions with a time component	"Had a job interview on Feb 10", "Deployed v2.0 today"
`hypothesis`	Uncertain information that needs confirmation	"Might be moving to NYC", "Seems interested in Python"

API Operations

1. Process Turn (Recommended for Conversations)

The simplest way to use CML. Sends the user's message, retrieves relevant context, and stores the message -- all in one call. Use this as your default approach.

bash

curl -s -X POST "${CML_BASE_URL:-http://localhost:8000}/api/v1/memory/turn" \
  -H "Authorization: Bearer ${CML_API_KEY}" \
  -H "Content-Type: application/json" \
  -d '{
    "user_message": "I just got promoted to senior engineer at Acme Corp!",
    "session_id": "openclaw-main",
    "max_context_tokens": 1500
  }'

Response contains memory_context (inject into your prompt), memories_retrieved, and memories_stored.

2. Store a Memory

Use when you learn something specific and want to store it with a particular type.

bash

curl -s -X POST "${CML_BASE_URL:-http://localhost:8000}/api/v1/memory/write" \
  -H "Authorization: Bearer ${CML_API_KEY}" \
  -H "Content-Type: application/json" \
  -d '{
    "content": "User is allergic to shellfish",
    "memory_type": "constraint",
    "session_id": "openclaw-main",
    "context_tags": ["health", "dietary"],
    "namespace": "openclaw"
  }'

3. Retrieve Memories

Query for relevant memories before answering questions about the user.

bash

curl -s -X POST "${CML_BASE_URL:-http://localhost:8000}/api/v1/memory/read" \
  -H "Authorization: Bearer ${CML_API_KEY}" \
  -H "Content-Type: application/json" \
  -d '{
    "query": "dietary restrictions and food preferences",
    "max_results": 10,
    "format": "llm_context"
  }'

Use "format": "llm_context" to get a pre-formatted string ready to inject into your prompt. Use "format": "packet" when you need structured data with individual memory items.

You can filter by memory type:

bash

curl -s -X POST "${CML_BASE_URL:-http://localhost:8000}/api/v1/memory/read" \
  -H "Authorization: Bearer ${CML_API_KEY}" \
  -H "Content-Type: application/json" \
  -d '{
    "query": "user restrictions",
    "memory_types": ["constraint", "preference"],
    "format": "llm_context"
  }'

4. Update a Memory

Provide feedback when a memory is confirmed correct, found incorrect, or outdated.

bash

curl -s -X POST "${CML_BASE_URL:-http://localhost:8000}/api/v1/memory/update" \
  -H "Authorization: Bearer ${CML_API_KEY}" \
  -H "Content-Type: application/json" \
  -d '{
    "memory_id": "<uuid-from-read-response>",
    "feedback": "correct"
  }'

Valid feedback values: correct, incorrect, outdated.

5. Forget Memories

When the user asks you to forget something.

bash

curl -s -X POST "${CML_BASE_URL:-http://localhost:8000}/api/v1/memory/forget" \
  -H "Authorization: Bearer ${CML_API_KEY}" \
  -H "Content-Type: application/json" \
  -d '{
    "query": "old home address",
    "action": "delete"
  }'

Actions: delete (permanent), archive (soft-delete, recoverable), silence (suppress from results).

6. Memory Statistics

Check what you have stored.

bash

curl -s "${CML_BASE_URL:-http://localhost:8000}/api/v1/memory/stats" \
  -H "Authorization: Bearer ${CML_API_KEY}"

Behavioral Guidelines

When to Store Memories

Store a memory immediately when the user shares:

•Personal information (name, location, job, family)
•Preferences or opinions ("I prefer...", "I like...", "I hate...")
•Constraints or restrictions ("I'm allergic to...", "Don't ever...", "I can't...")
•Important events ("I just...", "Yesterday I...", "Next week I...")
•Goals or plans ("I want to...", "I'm planning to...")

When to Retrieve Memories

Retrieve context before responding when:

•The user asks a question about themselves or past conversations
•You need to personalize a recommendation or suggestion
•The conversation topic relates to previously stored information
•The user references something from a prior conversation ("remember when...")

Best Practices

•Use /memory/turn as your default -- it handles both retrieval and storage in one call.
•Use /memory/write with explicit types when you identify a specific fact, preference, or constraint worth storing separately.
•Always include session_id to track conversation lineage.
•Use context_tags to categorize memories (e.g., ["work", "project-alpha"]).
•Inject retrieved context at the start of your reasoning when making personalized responses.
•Confirm before forgetting -- ask the user to confirm deletion of important memories.
•Mark incorrect memories with feedback: "outdated" instead of deleting, so CML can learn patterns.

Example Conversation Flows

Flow 1: Learning and Recalling a Preference

code

User: "I'm vegetarian and I really dislike spicy food"

Agent thinking:
  1. Store preference via /memory/write with type "preference"
  2. Store constraint via /memory/write with type "constraint"

[bash] curl -s -X POST "$CML_BASE_URL/api/v1/memory/write" \
  -H "Authorization: Bearer $CML_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"content":"User is vegetarian","memory_type":"preference","session_id":"openclaw-main","context_tags":["dietary"]}'

[bash] curl -s -X POST "$CML_BASE_URL/api/v1/memory/write" \
  -H "Authorization: Bearer $CML_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"content":"User dislikes spicy food","memory_type":"constraint","session_id":"openclaw-main","context_tags":["dietary"]}'

Agent: "Got it! I'll remember that you're vegetarian and prefer non-spicy food."

Later:

code

User: "Can you suggest a restaurant for dinner tonight?"

Agent thinking:
  1. Retrieve dietary preferences and constraints from CML

[bash] curl -s -X POST "$CML_BASE_URL/api/v1/memory/read" \
  -H "Authorization: Bearer $CML_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"query":"food preferences dietary restrictions","format":"llm_context"}'

  -> Returns: "User is vegetarian. User dislikes spicy food."

Agent: "Based on your preferences, here are some vegetarian-friendly restaurants
        with mild cuisine options..."

Flow 2: Using Process Turn for Seamless Memory

code

User: "I just accepted the offer at Google! Starting March 1st."

Agent thinking:
  1. Use /memory/turn to store this and retrieve any related context

[bash] curl -s -X POST "$CML_BASE_URL/api/v1/memory/turn" \
  -H "Authorization: Bearer $CML_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"user_message":"I just accepted the offer at Google! Starting March 1st.","session_id":"openclaw-main"}'

  -> Returns memory_context with any prior job-search memories
  -> Automatically stores this as a new memory

Agent: "Congratulations on the Google offer! That's a great next step after
        your interviews last month. March 1st start date noted!"