MCP tools reference

The TwinCommit MCP server exposes ten tools. Read-only tools are always available. Tools marked write require TWINCOMMIT_MCP_ALLOW_WRITES=true.

Tool	Access	Purpose
`list_pipelines`	read	Every pipeline with its source, target, state and current lag
`get_status`	read	Checkpoint position, open transactions, broken tables and last error
`get_lag`	read	Lag history over a time window
`start_pipeline`	write	Start or resume from the last committed checkpoint
`stop_pipeline`	write	Drain in-flight transactions and stop cleanly
`resnapshot_table`	write	Re-snapshot one table while the rest keep streaming
`verify_tables`	read	Compare source and target row counts and checksums
`explain_error`	read	Turn an error into a cause and a concrete fix
`check_source`	read	Run source prerequisite checks
`tail_events`	read	Recent change events for a table (values redacted by default)

list_pipelines

No parameters.

[
  { "name": "db2-prod-databricks", "source": "db2:PRODDB", "target": "databricks:prod.replica",
    "state": "streaming", "lag_seconds": 0.42, "caught_up": true, "broken_tables": 0 }
]

get_status

Parameter	Type	Required
`pipeline`	string	yes

{
  "pipeline": "db2-prod-databricks",
  "state": "streaming",
  "checkpoint": { "position": "0000000004F3E2A1", "commit_time": "2026-11-14T14:02:11Z" },
  "lag_seconds": 38.1,
  "open_transactions": [{ "id": "991204", "rows": 2100344, "spilled": true, "age_seconds": 41 }],
  "tables": { "streaming": 42, "snapshotting": 0, "broken": 0 },
  "last_error": null
}

get_lag

Parameter	Type	Required	Default
`pipeline`	string	yes
`window`	duration	no	`1h`
`step`	duration	no	`1m`

Returns [{ "t": "...", "lag_seconds": 0.4 }, ...]. History needs TWINCOMMIT_PROMETHEUS_URL; without it, only the current value is returned.

start_pipeline / stop_pipeline (write)

Parameter	Type	Required
`pipeline`	string	yes

stop_pipeline waits for the current batch to commit before stopping.

resnapshot_table (write)

Parameter	Type	Required
`pipeline`	string	yes
`table`	string (`SCHEMA.TABLE`)	yes
`recreate_target`	boolean	no (default `false`)

{ "table": "SALES.ORDERS", "state": "snapshotting", "rows_copied": 0, "started_at": "2026-11-14T14:10:00Z" }

verify_tables

Parameter	Type	Required
`pipeline`	string	yes
`tables`	string[]	no (default all)

[{ "table": "SALES.ORDERS", "source_rows": 1048211, "target_rows": 1048211, "checksum_match": true }]

explain_error

Parameter	Type	Required
`pipeline`	string	one of
`error`	string	one of

Returns { "cause": "...", "fix": ["..."], "docs": "https://twincommit.io/docs/..." }.

check_source

Parameter	Type	Required
`pipeline`	string	yes

Returns the same checks as twincommit check, each with ok and a fix command.

tail_events

Parameter	Type	Required	Default
`pipeline`	string	yes
`table`	string	yes
`limit`	integer	no	`20`

[{ "op": "U", "commit_ts": "2026-11-14T14:02:09Z", "key": { "ORDER_ID": "«redacted»" }, "columns_changed": ["STATUS"] }]