Streams API

Streams push updates as they happen over server-sent events (SSE), so a client does not have to poll. Every stream needs the VIEWER role.

Method and path	Carries
`GET /api/executions/{executionId}/status/stream`	Progress snapshots of one run
`GET /api/sessions/{sessionId}/executions/{executionId}/logs`	Log lines as text
`GET /api/sessions/{sessionId}/executions/{executionId}/logs/entries`	Log entries as JSON
`GET /api/sessions/{sessionId}/executions/{executionId}/results`	What reaches the terminal nodes
`GET /api/events/stream`	Events of all runs: status changes, control outcomes and log lines

Common behaviour

Request a stream with Accept: text/event-stream and keep the connection open. The response is a sequence of events separated by blank lines.

id: 0
data: {"executionId":"550e8400-e29b-41d4-a716-446655440000","status":"RUNNING"}

: ping

id: 1
data: {"executionId":"550e8400-e29b-41d4-a716-446655440000","status":"SUCCESS"}

The data of the example above is shortened. The sections below show the full shape of each stream.

Event ids. Each event has an id that counts from 0 within the stream, in the order the server delivers events.
Resuming. After a dropped connection, reconnect with the last id you saw in the Last-Event-ID header. The server replays the stream and skips everything up to that id, so nothing arrives twice. This works for the status, log and result streams; the event feed does not support it.
Keep-alive. An idle stream sends a comment line, : ping, every 15 seconds so proxies do not close the connection. Ignore comment lines.
Ending. The status, log and result streams end when the run reaches a final state. The event feed has no end.
Errors. A stream that cannot start answers with an ordinary JSON error before any event, for example 404 for an unknown run or one that belongs to another session.

Stream the status of a run

GET /api/executions/{executionId}/status/stream Sends a progress snapshot every time the run or one of its nodes changes. Each event’s data is the same object that GET /api/executions/{executionId} returns, so a client can use one parser for both. The stream completes when the run ends.

Query parameter	Default	Meaning
`includeHistory`	`true`	Replay the updates of the last few minutes first (`yukta.streaming.status-history-ttl-minutes`, default 5), then follow live. Keep it `true` when you resume with `Last-Event-ID`, so the ids line up

The deprecated path GET /api/workflow/{sessionId}/status/{executionId}/stream does the same and also checks the session.

GET /api/executions/550e8400-e29b-41d4-a716-446655440000/status/stream
Accept: text/event-stream

Stream the logs of a run

GET /api/sessions/{sessionId}/executions/{executionId}/logs Sends the stored log lines of the run first, then live lines until the run reaches a final state. For a run that has already finished, it sends the stored lines and ends. The server subscribes to live lines before it reads the stored ones, so a line written while the history loads is neither lost nor sent twice. Each event’s data is one formatted line.

id: 0
data: [2026-07-19T10:15:29.050Z] [INFO] [map/MAPPER] STDOUT: mapped 1 record

id: 1
data: [2026-07-19T10:15:29.088Z] [INFO] [end/CONSOLE_TERMINAL] STDOUT: {greeting=Hello, Ada}

How long stored lines are kept depends on the log store; see Observability.

Stream structured log entries

GET /api/sessions/{sessionId}/executions/{executionId}/logs/entries The same lines as JSON objects, for clients that filter by node or level. It behaves exactly like the text stream.

Field	Type	Meaning
`executionId`	string	The run
`pluginId`	string	The node that wrote the entry
`pluginName`	string	The plugin type of that node
`stream`	string	`STDOUT`, `STDERR` or a custom stream name
`message`	string	The text
`level`	string	`DEBUG`, `INFO`, `WARN` or `ERROR`
`timestamp`	string	When the entry was written

id: 0
data: {"executionId":"550e8400-e29b-41d4-a716-446655440000","pluginId":"map","pluginName":"MAPPER","stream":"STDOUT","message":"mapped 1 record","level":"INFO","timestamp":"2026-07-19T10:15:29.050Z"}

Stream the results of a run

GET /api/sessions/{sessionId}/executions/{executionId}/results Sends what reaches the terminal nodes: kept events first, then new ones until the run ends. The same path returns JSON when you ask for application/json; see Read the result of a run.

Query parameter	Meaning
`nodeId`	Only this terminal node. The final `EXECUTION_END` event is always sent

Each event’s data is a result event with kind (RESULT, NODE_END or EXECUTION_END), nodeId, sequence, payload (for RESULT), status (for the end events), truncated and timestamp. The stream ends after EXECUTION_END. A finished run whose results are no longer kept sends nothing and ends.

id: 0
data: {"kind":"RESULT","nodeId":"end","sequence":0,"payload":{"greeting":"Hello, Ada"},"truncated":false,"timestamp":"2026-07-19T10:15:29.090Z"}

id: 2
data: {"kind":"EXECUTION_END","sequence":2,"status":"SUCCESS","truncated":false,"timestamp":"2026-07-19T10:15:29.101Z"}

Stream events of all runs

GET /api/events/stream A live feed of what happens across the server, for monitors and external supervisors. It does not replay past events, and a reader that cannot keep up misses events. It has no Last-Event-ID support and does not end on its own.

Query parameter	Meaning
`executionId`	Only events of this run
`type`	Only this kind: `NodeStatusChanged`, `WorkflowStatusChanged`, `ControlOutcome` or `LogLine`. Not case sensitive
`severity`	Only this severity or higher: `INFO`, `WARN` or `ERROR`. An invalid value answers `400`

Each event’s data is an envelope with the event type, its severity and the event itself.

Type	Fields of `event`
`NodeStatusChanged`	`executionId`, `workflowId`, `nodeId`, `module`, `status`, `metadata`, `timestamp`
`WorkflowStatusChanged`	`executionId`, `workflowId`, `status`, `timestamp`
`ControlOutcome`	`executionId`, `command`, `actor`, `applied`, `reason`, `timestamp`
`LogLine`	`executionId`, `nodeId`, `line`, `timestamp`

Severity. A node or run that ends FAILURE, TIMED_OUT or ABORTED is ERROR. One that ends CANCELLED is WARN. A node that ends UPSTREAM_FAILED stays INFO, because it only reflects the node before it. A control command that was not applied is WARN. A log line is ERROR if it contains words such as error, failed, failure, exception or What went wrong, WARN if it contains warn, warning or deprecat, and INFO otherwise.

GET /api/events/stream?executionId=550e8400-e29b-41d4-a716-446655440000&severity=WARN
Accept: text/event-stream

id: 0
data: {"type":"NodeStatusChanged","severity":"ERROR","event":{"executionId":"550e8400-e29b-41d4-a716-446655440000","workflowId":"build","nodeId":"compile","module":"PROCESS_EXECUTOR","status":"FAILURE","metadata":{"error":"exit code 1"},"timestamp":"2026-07-19T10:15:29.500Z"}}

API basics

Endpoints

Common behaviour

Stream the status of a run

Stream the logs of a run

Stream structured log entries

Stream the results of a run

Stream events of all runs

​Common behaviour

​Stream the status of a run

​Stream the logs of a run

​Stream structured log entries

​Stream the results of a run

​Stream events of all runs

​Related

Common behaviour

Stream the status of a run

Stream the logs of a run

Stream structured log entries

Stream the results of a run

Stream events of all runs

Related