MCP Tools Reference: spanner.googleapis.com

Tool: commit

Commit a transaction in a given session. * If commit is finalizing the result of a DML statement then commit request should include latest precommit_token returned by execute_sql tool. * If response to commit includes another precommit_token then issue another commit call to finalize the transaction with the latest precommit_token.

The following sample demonstrate how to use curl to invoke the commit MCP tool.

Curl Request 
                  
curl --location 'https://spanner.googleapis.com/mcp' \
--header 'content-type: application/json' \
--header 'accept: application/json, text/event-stream' \
--data '{
  "method": "tools/call",
  "params": {
    "name": "commit",
    "arguments": {
      // provide these details according to the tool's MCP specification
    }
  },
  "jsonrpc": "2.0",
  "id": 1
}'

Input Schema

The request for Commit.

CommitRequest

JSON representation 
{
  "session": string,
  "transactionId": string,
  "precommitToken": {
    object (MultiplexedSessionPrecommitToken)
  }
}
Fields
session

string

Required. The session in which the transaction to be committed is running.
transactionId

string (bytes format)

Required. The transaction in which to commit. Commit a previously-started transaction.

A base64-encoded string.
precommitToken

object (MultiplexedSessionPrecommitToken)

Required. You must include the precommit token with the highest sequence number received in this transaction attempt. Failing to do so results in a FailedPrecondition error.

MultiplexedSessionPrecommitToken

JSON representation 
{
  "precommitToken": string,
  "seqNum": integer
}
Fields
precommitToken

string (bytes format)

Opaque precommit token.

A base64-encoded string.
seqNum

integer

An incrementing seq number is generated on every precommit token that is returned. Clients should remember the precommit token with the highest sequence number from the current transaction attempt.

Output Schema

The response for Commit.

CommitResponse

JSON representation 
{
  "commitTimestamp": string,
  "commitStats": {
    object (CommitStats)
  },
  "snapshotTimestamp": string,

  // Union field MultiplexedSessionRetry can be only one of the following:
  "precommitToken": {
    object (MultiplexedSessionPrecommitToken)
  }
  // End of list of possible types for union field MultiplexedSessionRetry.
}
Fields
commitTimestamp

string (Timestamp format)

The Cloud Spanner timestamp at which the transaction committed.

Uses RFC 3339, where generated output will always be Z-normalized and use 0, 3, 6 or 9 fractional digits. Offsets other than "Z" are also accepted. Examples: "2014-10-02T15:01:23Z", "2014-10-02T15:01:23.045123456Z" or "2014-10-02T15:01:23+05:30".
commitStats

object (CommitStats)

The statistics about this Commit. Not returned by default. For more information, see CommitRequest.return_commit_stats.
snapshotTimestamp

string (Timestamp format)

If TransactionOptions.isolation_level is set to IsolationLevel.REPEATABLE_READ, then the snapshot timestamp is the timestamp at which all reads in the transaction ran. This timestamp is never returned.

Uses RFC 3339, where generated output will always be Z-normalized and use 0, 3, 6 or 9 fractional digits. Offsets other than "Z" are also accepted. Examples: "2014-10-02T15:01:23Z", "2014-10-02T15:01:23.045123456Z" or "2014-10-02T15:01:23+05:30".
Union field MultiplexedSessionRetry. You must examine and retry the commit if the following is populated. MultiplexedSessionRetry can be only one of the following:
precommitToken

object (MultiplexedSessionPrecommitToken)

If specified, transaction has not committed yet. You must retry the commit with the new precommit token.

Timestamp

JSON representation 
{
  "seconds": string,
  "nanos": integer
}
Fields
seconds

string (int64 format)

Represents seconds of UTC time since Unix epoch 1970-01-01T00:00:00Z. Must be between -62135596800 and 253402300799 inclusive (which corresponds to 0001-01-01T00:00:00Z to 9999-12-31T23:59:59Z).
nanos

integer

Non-negative fractions of a second at nanosecond resolution. This field is the nanosecond portion of the duration, not an alternative to seconds. Negative second values with fractions must still have non-negative nanos values that count forward in time. Must be between 0 and 999,999,999 inclusive.

CommitStats

JSON representation 
{
  "mutationCount": string
}
Fields
mutationCount

string (int64 format)

The total number of mutations for the transaction. Knowing the mutation_count value can help you maximize the number of mutations in a transaction and minimize the number of API round trips. You can also monitor this value to prevent transactions from exceeding the system limit. If the number of mutations exceeds the limit, the server returns INVALID_ARGUMENT.

MultiplexedSessionPrecommitToken

JSON representation 
{
  "precommitToken": string,
  "seqNum": integer
}
Fields
precommitToken

string (bytes format)

Opaque precommit token.

A base64-encoded string.
seqNum

integer

An incrementing seq number is generated on every precommit token that is returned. Clients should remember the precommit token with the highest sequence number from the current transaction attempt.

Tool Annotations

Destructive Hint: ✅ | Idempotent Hint: ❌ | Read Only Hint: ❌ | Open World Hint: ❌