Observability Usage Guide

How to inspect observability data through the currently supported internal Python helper and the existing gateway dashboards. The query helper is read-only; this document does not define a production REST/CLI entry point for script promotion.

1. Internal Python Usage

Maintainers and explicitly authorized operators can query data through the ObservabilityQuery Python API. It is not wired into an agent or gateway handler, and its repeated-script candidates are advisory evidence only.

Prerequisites

The gateway admin SQLite database must exist on the machine. It is created automatically when the gateway runs for the first time. The default path is:

<tempdir>/dcc-mcp-registry/gateway_admin.sqlite

Override with DCC_MCP_GATEWAY_ADMIN_DB environment variable.

Basic queries

python

from dcc_mcp_core import ObservabilityQuery

query = ObservabilityQuery(db_path="/path/to/gateway_admin.sqlite")

# Session statistics
stats = query.get_session_stats(
    dcc_type="maya",
    since_ms=1700000000000,
)

print(stats["data"])
# {
#   "total_sessions": 42,
#   "active_sessions": 3,
#   "ended_normally": 35,
#   "ended_abnormally": 4,
#   "avg_duration_ms": 312000.0,
#   "total_tool_calls": 1280,
#   "total_errors": 15,
# }

# Tool-call statistics
tool_stats = query.get_tool_call_stats(
    tool_name="maya__poly_sphere",
    since_ms=1700000000000,
    limit=50,
)

print(tool_stats["data"]["stats"])
# {
#   "total_calls": 200,
#   "success_count": 195,
#   "failure_count": 5,
#   "success_rate": 0.975,
#   "avg_duration_ms": 45.2,
# }

print(tool_stats["data"]["events"])  # list of individual call records

Repeated-script review candidates

get_repeated_scripts() groups by the complete identity sha256 + reuse_key + dcc_type + tool_name. Each returned candidate_id is a stable hash of that canonical tuple. A candidate always has decision="manual_review" and recommended_action="human_review_only". No API in this package promotes, publishes, or edits a skill automatically; the task owner must perform a separate human review and authorization step.

Session tree

python

# All root sessions
tree = query.get_session_tree(dcc_type="maya")

# Drill into one session
children = query.get_session_tree(root_session_id="sess-abc123")

Coverage and crash stats

python

# Gateway coverage ratio
cov = query.get_coverage_stats(since_ms=1700000000000)

# Crash analysis
crashes = query.get_crash_stats(dcc_type="houdini", since_ms=1700000000000)

Diagnostic checks

python

# Does the database exist?
from pathlib import Path
db = Path("/path/to/gateway_admin.sqlite")
if not db.exists():
    print("Gateway has never run on this machine — no observability data.")

# Are there recent sessions?
stats = query.get_session_stats()
if stats["data"]["total_sessions"] == 0:
    print("No sessions recorded yet.")

Agent context for call attribution

When making MCP or REST calls through the gateway, attach agent context for observability correlation:

python

# MCP: attach context to params._meta
params = {
    "name": "maya__poly_sphere",
    "arguments": {"radius": 2.0},
    "_meta": {
        "agent_context": {
            "agent_id": "my-agent",
            "agent_name": "SceneBuilder",
            "turn_id": "turn-42",
            "model": "claude-sonnet-4-20250514",
        }
    }
}

json

// REST: attach context to meta.agent_context
POST /v1/call
{
  "tool": "maya__poly_sphere",
  "args": {"radius": 2.0},
  "meta": {
    "agent_context": {
      "agent_id": "my-agent",
      "turn_id": "turn-42"
    }
  }
}

2. Existing CLI Usage

The existing dcc-mcp-cli stats command queries the gateway admin SQLite database. It does not expose ObservabilityQuery.get_repeated_scripts() or a promotion command.

Quick start

bash

# Show summary statistics
dcc-mcp-cli stats

# Filter by time range
dcc-mcp-cli stats --since 1h
dcc-mcp-cli stats --since 24h
dcc-mcp-cli stats --since 7d

# Filter by DCC type
dcc-mcp-cli stats --dcc maya
dcc-mcp-cli stats --dcc blender

# Show top tools
dcc-mcp-cli stats --top-tools 10

# Show session breakdown
dcc-mcp-cli stats --sessions

Output format

=== Session Statistics (last 24h) ===
Total sessions:    42
Active:             3
Ended normally:    35
Ended abnormally:   4
Avg duration:     5.2m
Total tool calls: 1,280
Total errors:       15

=== Tool Call Performance ===
Tool                  Calls  Success  P95(ms)  P99(ms)
maya__poly_sphere      200   97.5%     120      340
blender__bevel_edge     50   94.0%      85      210
houdini__vdb_fog        30   96.7%     450     1200

=== Coverage ===
Observed:   1,250
Unobserved:   30
Coverage:   97.7%

3. Admin UI Usage

The gateway serves a read-only HTML dashboard at GET /admin when the gateway process is running.

Dashboard sections

Tab	Endpoint	What you see
Calls	`GET /admin/api/calls`	Recent audit records: request_id, tool, DCC, duration, success/failure.
Traces	`GET /admin/api/traces?limit=200`	Dispatch waterfalls with bounded input/output payloads.
Stats	`GET /admin/api/stats?range=1h`	Aggregated success rate, latency percentiles, top tools/instances, hourly distribution.
Workflows	`GET /admin/api/workflows?limit=200`	Session/workflow chains with agent metadata and step links.
Workers	`GET /admin/api/workers`	Per-instance registry cards (live DCC backends).
Traffic	`GET /admin/api/traffic?limit=300`	Capture status and retained metadata-only frames.
Governance	`GET /admin/api/governance?limit=300`	Policy decisions, redaction paths, quota state.
Skills	Admin UI page	Skill paths, load states, health.
Marketplace	Admin UI page	Marketplace extension browsing.
Instances	Admin UI page	DCC instances and their connection status.

Enabling audit persistence

By default audit data lives in an in-memory ring buffer. For persistence across gateway restarts, set:

bash

DCC_MCP_GATEWAY_AUDIT_DIR=/var/log/dcc-mcp/audit  # enables JSONL files
DCC_MCP_GATEWAY_AUDIT_MAX_ROWS=5000                # default, rows per file

When set, the gateway writes audit.jsonl and traces.jsonl to that directory and seeds the in-memory buffers from these files on restart.

Enabling SQLite persistence

Build the gateway with the admin-persist-sqlite Cargo feature:

toml

dcc-mcp-gateway = { features = ["admin-persist-sqlite"] }

The gateway then persists every trace, audit, skill path change, and deregistered instance to gateway_admin.sqlite. The SQLite lane runs on a background writer thread and never blocks the hot path.

Prometheus integration

bash

# Scrape a DCC server's metrics
curl -u scraper:change-me http://localhost:8765/metrics

# Add to prometheus.yml
scrape_configs:
  - job_name: dcc-mcp
    scrape_interval: 15s
    static_configs:
      - targets: ["host:8765", "host:8766"]
    metrics_path: /metrics
    basic_auth:
      username: scraper
      password_file: /etc/prometheus/dcc-mcp.pass

4. OTLP Trace Correlation

Jaeger

bash

docker run -d --name jaeger \
  -p 4317:4317 \
  -p 16686:16686 \
  jaegertracing/all-in-one:latest

OTEL_EXPORTER_OTLP_ENDPOINT=http://localhost:4317 \
OTEL_SERVICE_NAME=dcc-mcp-gateway \
  dcc-mcp-server

Grafana Tempo

yaml

# docker-compose.yml
services:
  tempo:
    image: grafana/tempo:latest
    ports: ["4317:4317", "3200:3200"]

Phoenix

Route through an OpenTelemetry Collector (the Rust exporter uses OTLP/gRPC; Phoenix accepts OTLP/HTTP):

yaml

receivers:
  otlp:
    protocols:
      grpc:
        endpoint: 0.0.0.0:4317
exporters:
  otlphttp/phoenix:
    traces_endpoint: http://phoenix:6006/v1/traces
service:
  pipelines:
    traces:
      receivers: [otlp]
      exporters: [otlphttp/phoenix]

5. Python ToolRecorder (In-Process Metrics)

For lightweight per-tool telemetry without a database:

python

from dcc_mcp_core import ToolRecorder

recorder = ToolRecorder("maya")

# Context manager (recommended)
with recorder.start("create_sphere", "maya") as guard:
    result = cmds.polySphere(r=2.0)

# Query results
metrics = recorder.metrics("create_sphere")
if metrics:
    print(f"Calls: {metrics.invocation_count}")
    print(f"Success: {metrics.success_rate():.1%}")
    print(f"P95: {metrics.p95_duration_ms:.1f} ms")

Observability Usage Guide ​

1. Internal Python Usage ​

Prerequisites ​

Basic queries ​

Repeated-script review candidates ​

Session tree ​

Coverage and crash stats ​

Diagnostic checks ​

Agent context for call attribution ​

2. Existing CLI Usage ​

Quick start ​

Output format ​

3. Admin UI Usage ​

Dashboard sections ​

Enabling audit persistence ​

Enabling SQLite persistence ​

Prometheus integration ​

4. OTLP Trace Correlation ​

Jaeger ​

Grafana Tempo ​

Phoenix ​

5. Python ToolRecorder (In-Process Metrics) ​

Observability Usage Guide

1. Internal Python Usage

Prerequisites

Basic queries

Repeated-script review candidates

Session tree

Coverage and crash stats

Diagnostic checks

Agent context for call attribution

2. Existing CLI Usage

Quick start

Output format

3. Admin UI Usage

Dashboard sections

Enabling audit persistence

Enabling SQLite persistence

Prometheus integration

4. OTLP Trace Correlation

Jaeger

Grafana Tempo

Phoenix

5. Python ToolRecorder (In-Process Metrics)