MCP

Model Context Protocol (MCP) is the simplest way to integrate Delx into an agent runtime. Use MCP when you want a stable tool schema and predictable, machine-readable outputs.

Endpoint

POST https://api.delx.ai/v1/mcp

Protocol

Delx MCP is JSON-RPC 2.0 over Streamable HTTP. You typically call tools/list for discovery and tools/call to run a tool.

Discover Tools

curl -sS https://api.delx.ai/v1/mcp \
  -H 'content-type: application/json' \
  -d '{
    "jsonrpc": "2.0",
    "id": 1,
    "method": "tools/list",
    "params": { "format": "compact", "tier": "core" }
  }'

DX note: in format=compact, Delx includes inline schema_url and a copy-pasteable example payload per tool.

If you need full input schemas in one round-trip, pass inline_schemas=true.

Formats available: full, compact, names, minimal, ultracompact. Use ultracompact for routing-only decisions, then fetch schemas on demand via GET https://api.delx.ai/api/v1/tools/schema/<tool_name>.

Start A Session

curl -sS https://api.delx.ai/v1/mcp \
  -H 'content-type: application/json' \
  -d '{
    "jsonrpc": "2.0",
    "id": 2,
    "method": "tools/call",
    "params": {
      "name": "start_therapy_session",
      "arguments": { "agent_id": "agent-123", "source": "openwork" }
    }
  }'

The response includes a session_id (UUID). You can pass it in tool arguments, or set x-delx-session-id header to inject it automatically into tools/call and tools/batch requests. For quick testing, you can also pass ?session_id=<SESSION_ID> on the MCP URL.

Process One Failure

curl -sS https://api.delx.ai/v1/mcp \
  -H 'content-type: application/json' \
  -H 'x-delx-session-id: <SESSION_ID>' \
  -d '{
    "jsonrpc": "2.0",
    "id": 3,
    "method": "tools/call",
    "params": {
      "name": "process_failure",
      "arguments": {
        "failure_type": "timeout",
        "context": "Rate limit storm (429). Retries escalated to 47. Constraints: no_external_http=true; no_secret_exposure=true."
      }
    }
  }'

What to store

• controller_update: copy-paste summary for a human controller.
• next_action: a single concrete step your runtime can execute.
• session_score: a numeric score for tracking outcomes over time.

DX discovery (HTTP)

• Tools catalog: GET https://api.delx.ai/api/v1/tools
• Super-compact catalog: GET https://api.delx.ai/api/v1/tools?format=ultracompact&tier=core
• One tool schema: GET https://api.delx.ai/api/v1/tools/schema/<tool_name>
• Validate session_id before tool calls: GET https://api.delx.ai/api/v1/session-validate?session_id=<uuid> (alias: /api/v1/session/validate)
• Fast runtime/session check: GET https://api.delx.ai/api/v1/status?session_id=<uuid>

Agent-native discovery

• Capabilities registry: GET https://api.delx.ai/.well-known/delx-capabilities.json
• Reliability signals: GET https://api.delx.ai/api/v1/reliability
• Pricing is protocol-native: paid calls return HTTP 402 with x402 requirements; machine-readable pricing is in GET https://api.delx.ai/api/v1/tools.
• Setup guide for controller-side payment loop: /docs/x402-setup

Agent-friendly spec

If your agent prefers a JSON artifact: GET /spec/mcp.json