@contextcapsule/mcp-server

MCP server for Context Capsule — portable execution context for AI agent workflows. Create and fetch structured context capsules that carry decisions, next steps, and working memory between agents and sessions.

Tools

create_capsule

Create a context capsule to hand off execution context between agents or sessions.

| Parameter | Type | Required | Description | |-----------|------|----------|-------------| | summary | string | Yes | What happened — max 500 chars | | decisions | string[] | No | Key decisions made (max 20 items) | | next_steps | string[] | No | What should happen next (max 20 items) | | payload | object | No | Structured JSON data (max 32KB) | | refs | object | No | Workflow references (workflow_id, agent_id, etc.) | | expires_in | number | No | TTL in seconds (60–604800, default 7 days) | | idempotency_key | string | No | Prevents duplicate capsules on retry | | audience | "human" | No | Enrich view page with social cards |

Requires: CONTEXTCAPSULE_API_KEY environment variable.

fetch_capsule

Fetch a capsule to resume work from where another agent left off.

| Parameter | Type | Required | Description | |-----------|------|----------|-------------| | capsule_id | string | Yes | The capsule ID (starts with cap_) |

No API key required.

signup

Get a free API key (500 capsules/month).

| Parameter | Type | Required | Description | |-----------|------|----------|-------------| | email | string | Yes | Your email address |

No API key required.

Usage Example

You: "Create a capsule summarizing the database migration we just finished"

Agent calls create_capsule:
  summary: "Migrated user table — split into users + profiles with dual-write"
  decisions: ["Used addColumn for backward compat", "2-week transition period"]
  next_steps: ["Run integration tests", "Update API serializers"]
  refs: { workflow_id: "migration-456", agent_id: "schema-agent" }

→ Returns capsule_id and capsule_url

You: "Fetch capsule cap_abc123 and continue the migration work"

Agent calls fetch_capsule:
  capsule_id: "cap_abc123"

→ Returns full context: summary, decisions, next_steps, payload, refs
→ Agent picks up exactly where the previous session left off

Setup

Claude Desktop

Add to claude_desktop_config.json:

{
  "mcpServers": {
    "contextcapsule": {
      "command": "npx",
      "args": ["-y", "@contextcapsule/mcp-server"],
      "env": {
        "CONTEXTCAPSULE_API_KEY": "ak_your_key_here"
      }
    }
  }
}

Cursor / Windsurf

Add to MCP settings:

{
  "mcpServers": {
    "contextcapsule": {
      "command": "npx",
      "args": ["-y", "@contextcapsule/mcp-server"],
      "env": {
        "CONTEXTCAPSULE_API_KEY": "ak_your_key_here"
      }
    }
  }
}

Claude Code

claude mcp add contextcapsule -- npx -y @contextcapsule/mcp-server

Then set your API key in your environment or .env file.

Configuration

| Variable | Required | Description | |----------|----------|-------------| | CONTEXTCAPSULE_API_KEY | For creating capsules | Your API key (starts with ak_) | | CONTEXTCAPSULE_BASE_URL | No | API base URL (default: https://www.contextcapsule.ai) |

Get an API Key

Use the signup tool from any MCP client, or:

curl -X POST https://www.contextcapsule.ai/v1/auth/signup \
  -H "Content-Type: application/json" \
  -d '{"email": "[email protected]", "source": "api"}'

Links

• Live Site
• API Docs
• ProofSlip (sister product — receipts + verification)
• GitHub

License

MIT