Eclipse Ditto

Eclipse Ditto MCP Server

A Model Context Protocol (MCP) server for Eclipse Ditto — the open-source (EPL-2.0) digital twin framework. It exposes Ditto's HTTP API as MCP tools so an AI agent can manage devices ("things"), their attributes/features, policies, connections, and cluster admin — the full Ditto HTTP API surface.

Since Bosch IoT Things and other commercial IoT platforms are built on Ditto's open protocol, this server also works against those deployments — nothing in the code is vendor-specific.

Built with FastMCP.

Tools

Things

Tool	Description
list_things(namespaces, filter, fields, limit)	Search/list things. filter is a Ditto RQL expression, e.g. eq(attributes/location,"lab-1").
count_things(namespaces, filter)	Count things matching a filter without fetching them.
get_things(thing_ids, fields)	Bulk-fetch multiple things by ID in one request.
get_thing(thing_id, fields)	Fetch the full digital twin for one thing.
put_thing(thing_id, thing, overwrite=False)	Create a thing, or replace one with overwrite=True.
patch_thing(thing_id, patch)	Partially update a thing via RFC-7396 JSON Merge Patch.
delete_thing(thing_id, confirm=False)	Delete a thing. Irreversible.
get_thing_policy_id / set_thing_policy_id	Read/repoint the policy controlling a thing.
get_thing_definition / set_thing_definition / delete_thing_definition	Manage a thing's WoT/model definition.
whoami()	Return the identity Ditto authenticated this connector as — useful to sanity-check credentials.

Attributes & Features

Tool	Description
get_thing_attributes(thing_id, path=None)	Get all attributes, or one by JSON pointer path.
set_thing_attributes(thing_id, value, path=None, overwrite=False)	Set the whole attributes object, or one attribute.
delete_thing_attributes(thing_id, path=None, confirm=False)	Delete attributes (whole object or one path).
get_thing_features(thing_id)	Get all features (sensor/actuator state).
get_feature / put_feature / delete_feature	Read/create-replace/delete one whole feature.
get_feature_properties / set_feature_properties / delete_feature_properties	Read/write/delete feature properties or desiredProperties, whole or by path.
get_feature_definition / set_feature_definition / delete_feature_definition	Manage a feature's definition.

Messages

Tool	Description
send_message(thing_id, subject, payload, feature_id=None, direction="inbox", timeout=10)	Send a live message to/from a thing or feature (e.g. invoke a device operation).
claim_thing(thing_id, payload=None, timeout=10)	Send a claim message to gain access to a thing.

Policies

Tool	Description
get_policy / put_policy / delete_policy	Read/create-replace/delete a policy.
get_policy_entries(policy_id, label=None)	Read all entries, or one by label.
set_policy_entry / delete_policy_entry	Create-replace/delete one policy entry.

Connectivity & DevOps (require DITTO_DEVOPS_USERNAME/DITTO_DEVOPS_PASSWORD)

Ditto's Connections API and DevOps API (log levels, cluster config, piggyback commands) sit behind a separate "devops" Basic-auth realm on the gateway, independent of the policy-based auth used for things/policies.

Tool	Description
list_connections / get_connection	List/fetch connection configs.
create_connection(connection, dry_run=False)	Create a connection (ID generated by Ditto).
update_connection(connection_id, connection)	Update an existing connection (404 if it doesn't exist).
delete_connection(connection_id, confirm=False)	Delete a connection.
get_connection_status / get_connection_metrics / get_connection_logs	Inspect a connection's live state.
send_connection_command(connection_id, command)	Open/close/reset-metrics/enable-logs/reset-logs.
get_logging_config / set_logging_config	Read/set cluster log levels.
get_devops_config(path)	Read cluster-wide runtime config.
send_devops_piggyback(command, service_name=None, instance_index=None)	Low-level admin command — Ditto's most powerful, least-guarded API. Use with care.

Live events

Tool	Description
poll_thing_changes(thing_ids, namespaces, filter, fields, duration_seconds=10, max_events=50)	Open a short-lived SSE connection and collect live thing-change events. A request/response approximation of Ditto's persistent change feed — see caveat below.

Safety conventions

• Create vs. replace: every put_*/set_*/create_* tool defaults to overwrite=False, using Ditto's If-None-Match: * header so create-only is race-free (not a check-then-set). Pass overwrite=True to replace existing data.
• Deletes are confirm-gated: every delete_* tool requires confirm=True. There is no bulk/cascading delete.
• Not covered (deliberately): WoT Web-of-Things descriptor endpoints (/.well-known/wot, /devops/wot/*), and fine-grained policy sub-resources (subjects/{id}, resources/{path}, imports, token-integration actions) — whole-entry set_policy_entry/get_policy_entries covers the common case. Add these later if you need them.

Configuration

Env var	Required	Description
DITTO_BASE_URL	Yes	Base URL of the Ditto HTTP API, e.g. http://localhost:8080 or your gateway's public URL.
DITTO_USERNAME / DITTO_PASSWORD	No	Basic auth for the Things/Policies/Messages/Search API. Typical for self-hosted Ditto (nginx demo setup uses ditto/ditto).
DITTO_BEARER_TOKEN	No	Bearer token, used instead of Basic auth for the same API. Typical for OAuth2-fronted deployments (e.g. Bosch IoT Things).
DITTO_DEVOPS_USERNAME / DITTO_DEVOPS_PASSWORD	No	Basic auth for the separate DevOps/Connections realm (self-hosted default: devops/foobar). Required only for the Connectivity and DevOps tools.

If both DITTO_BEARER_TOKEN and Basic auth credentials are set, the bearer token takes precedence. If neither is set, requests are sent unauthenticated (only works if your Ditto instance allows anonymous/pre-authenticated access).

Running locally

uv sync
export DITTO_BASE_URL=http://localhost:8080
export DITTO_USERNAME=ditto
export DITTO_PASSWORD=ditto
export DITTO_DEVOPS_USERNAME=devops    # only needed for connectivity/devops tools
export DITTO_DEVOPS_PASSWORD=foobar
uv run dittomcpserver.py

See mcp.json for ready-to-use client configs (stdio and Docker).

Testing against a real Ditto instance

This repo's design principles call for testing against a real instance rather than mocks. docker-compose.yml (adapted from Ditto's official example, trimmed to the services this connector needs) spins up a full local Ditto stack — MongoDB, the Ditto microservices, and an nginx front door with Basic auth.

docker compose up -d       # start Ditto on http://localhost:8080 (user: ditto / pass: ditto; devops: devops / foobar)
uv run pytest -v           # tests/conftest.py also starts/stops the stack automatically
docker compose down        # stop it manually if you started it yourself

The 47 tests cover every tool group (things, attributes/features, messages, policies, connectivity, devops, live events) against this real stack, including delete/confirm gating and create/overwrite gating.

A note on the live-events approximation

poll_thing_changes opens Ditto's SSE change feed for a bounded window instead of holding a persistent subscription (which doesn't map cleanly onto a single MCP tool call). Ditto's SSE stream sends periodic empty data: keepalive lines even when nothing has changed — the tool checks its deadline on every line received, including keepalives, so it reliably returns within duration_seconds regardless of how chatty or quiet the stream is.

License notes

docker-compose.yml and the files under docker/ are adapted from the Eclipse Ditto project (EPL-2.0) and are used here only to spin up a local test instance — they are not part of the MCP server itself.