The POST /stream/ask endpoint allows you to ask a question and receive step-by-step progress updates as the AI processes your request — including SQL generation, execution, and summary creation.

This is the streaming version of /ask, ideal for frontend apps (e.g., chatbots) that want to show real-time feedback to users.

What It Does

The endpoint returns a Server-Sent Events (SSE) stream that includes:

System messages about each processing step (e.g., SQL generation start, execution complete).
Final outputs like the generated SQL and natural language summary.
Intermediate explanations, such as rephrased questions and reasoning paths.

Basic Usage

{
  "question": "List the top 5 states with the most customers"
}

This simplified stream shows the key phases of a /stream/ask request — from understanding and generating SQL, to executing it, and finally producing a streamed summary.

// Stream begins
data: { "type": "message_start" }

// SQL Generation Stages
data: { "type": "state", "data": { "state": "sql_generation_start" }}
data: { "type": "state", "data": { "state": "sql_generation_understanding" }}
data: { "type": "state", "data": { "state": "sql_generation_searching" }}
data: { "type": "state", "data": { "state": "sql_generation_planning" }}
data: { "type": "state", "data": { "state": "sql_generation_generating" }}
data: { "type": "state", "data": { "state": "sql_generation_success", "sql": "SELECT ... LIMIT 5" }}

// SQL Execution
data: { "type": "state", "data": { "state": "sql_execution_start" }}
data: { "type": "state", "data": { "state": "sql_execution_end" }}

// Summary Generation (streamed content block)
data: { "type": "content_block_start", "content_block": { "type": "text", "name": "summary_generation" }}
data: { "type": "content_block_delta", "delta": { "text": "Here" }}
data: { "type": "content_block_delta", "delta": { "text": " are" }}
data: { "type": "content_block_delta", "delta": { "text": " the first 5 customers from the dataset." }}
data: { "type": "content_block_stop" }

// Stream ends
data: { "type": "message_stop" }

This example omits several detailed properties (such as question, rephrasedQuestion, intentReasoning, traceId, and timestamp) for clarity. Refer to the full schema for a complete breakdown of all available fields.

State Lifecycle

graph TD
  message_start["message_start"]
  sql_start["sql_generation_start"]
  sql_understanding["sql_generation_understanding"]
  sql_searching["sql_generation_searching"]
  sql_planning["sql_generation_planning"]
  sql_generating["sql_generation_generating"]
  sql_correcting["sql_generation_correcting"]
  sql_success["sql_generation_success"]
  sql_failed["sql_generation_failed"]
  sql_stopped["sql_generation_stopped"]

  sql_exec_start["sql_execution_start"]
  sql_exec_end["sql_execution_end"]

  summary_start["content_block_start: summary_generation"]
  summary_streaming["content_block_delta (text)"]
  summary_stop["content_block_stop"]

  error_event["type: error"]
  message_stop["message_stop"]

  %% Normal flow
  message_start -->|"Trigger SQL generation"| sql_start
  sql_start --> sql_understanding --> sql_searching --> sql_planning --> sql_generating

  sql_generating -->|"Auto-correct (if needed)"| sql_correcting
  sql_correcting --> sql_success
  sql_generating --> sql_success

  sql_success -->|"Run SQL"| sql_exec_start --> sql_exec_end

  sql_exec_end -->|"Start LLM summary"| summary_start
  summary_start --> summary_streaming --> summary_stop --> message_stop

  %% Error flows
  sql_generating -->|"Too many corrections failed"| sql_failed -->|"Emit error event"| error_event --> message_stop
  sql_generating -->|"User canceled"| sql_stopped --> message_stop
  sql_exec_start -->|"SQL execution error"| error_event --> message_stop
  summary_start -->|"LLM failed to summarize"| error_event --> message_stop

Event Types

During a /stream/ask request, the API streams a sequence of events using Server-Sent Events (SSE). Each event provides insight into the system’s current state or output.

message_start

Purpose: Indicates the start of a new streaming response.
Payload: Contains the timestamp when the process began.

{
  "type": "message_start",
  "timestamp": 1751014954139
}

state

Purpose: Describes what stage the system is in during processing.

State Lifecycle Overview

`state`	Description
`sql_generation_start`	The system has begun processing the user’s question.
`sql_generation_understanding`	The AI is interpreting the question and trying to identify its intent.
`sql_generation_searching`	The AI is searching relevant tables and metadata to answer the question.
`sql_generation_planning`	A plan for how to generate SQL is being formed, including table joins or filters.
`sql_generation_generating`	The SQL is being generated.
`sql_generation_correcting`	A generated SQL failed to execute and is being corrected. (Auto-retry phase)
`sql_generation_success`	SQL was successfully generated. The `sql` field will be included.
`sql_generation_failed`	SQL generation failed. Followed by an error event.
`sql_generation_stopped`	SQL generation was manually canceled or interrupted (e.g. client disconnected).
`sql_generation_finished`	Final state for SQL generation (used internally; usually followed by `success` or `failed`).
`sql_execution_start`	SQL execution has started.
`sql_execution_end`	SQL execution has completed (successfully or not).

`data` Field Reference (`"type": "state"`)

🔹 sql_generation_start

Field	Type	Description
`state`	`string`	`"sql_generation_start"`
`question`	`string`	The original user input.
`threadId`	`string`	Unique thread identifier.
`language`	`string`	Language used for summarization (e.g., `"English"`).

🔹 SQL Generation In-Progress States
(e.g., sql_generation_understanding, searching, planning, generating, correcting)

Field	Type	Description
`state`	`string`	Current generation state, such as `"sql_generation_searching"`, `"sql_generation_planning"`, etc.
`pollCount`	`number`	Number of polling attempts so far.
`rephrasedQuestion`	`string` \| `null`	Reformulated version of the user query.
`intentReasoning`	`string` \| `null`	AI’s interpretation of what the user is asking.
`sqlGenerationReasoning`	`string` \| `null`	Step-by-step reasoning of SQL generation. Appears during `generating`.
`retrievedTables`	`string[]` \| `null`	List of tables determined to be relevant.
`invalidSql`	`string` \| `null`	SQL that failed during correction attempts (optional).
`traceId`	`string`	For backend debugging.

🔹 sql_generation_success

Field	Type	Description
`state`	`"sql_generation_success"`	Marks the completion of SQL generation.
`sql`	`string`	The generated SQL query.

🔹 sql_execution_start

Field	Type	Description
`state`	`"sql_execution_start"`	SQL execution has begun.
`sql`	`string`	The SQL query being executed.

🔹 sql_execution_end

Field	Type	Description
`state`	`"sql_execution_end"`	SQL execution completed. No additional fields.

Example

data: {
  "type": "state",
  "data": {
    "state": "sql_generation_start",
    "question": "list 5 customers",
    "threadId": "0625991d-1bba-407d-8ad4-dd0210172484",
    "language": "English"
  },
  "timestamp": 1751014954142
}

data: {
  "type": "state",
  "data": {
    "state": "sql_generation_understanding",
    "pollCount": 1,
    "rephrasedQuestion": null,
    "intentReasoning": null,
    "sqlGenerationReasoning": null,
    "retrievedTables": null,
    "invalidSql": null,
    "traceId": "f218b1f7-4623-4a56-8b66-18d544797b20"
  },
  "timestamp": 1751014954165
}

data: {
  "type": "state",
  "data": {
    "state": "sql_generation_searching",
    "pollCount": 4,
    "rephrasedQuestion": "List 5 customers from the olist_customers_dataset table.",
    "intentReasoning": "User wants to retrieve specific customer data, likely using SQL query.",
    "sqlGenerationReasoning": null,
    "retrievedTables": null,
    "invalidSql": null,
    "traceId": "f218b1f7-4623-4a56-8b66-18d544797b20"
  },
  "timestamp": 1751014957183
}

data: {
  "type": "state",
  "data": {
    "state": "sql_generation_planning",
    "pollCount": 6,
    "rephrasedQuestion": "List 5 customers from the olist_customers_dataset table.",
    "intentReasoning": "User wants to retrieve specific customer data, likely using SQL query.",
    "sqlGenerationReasoning": null,
    "retrievedTables": ["olist_customers_dataset"],
    "invalidSql": null,
    "traceId": "f218b1f7-4623-4a56-8b66-18d544797b20"
  },
  "timestamp": 1751014959232
}

data: {
  "type": "state",
  "data": {
    "state": "sql_generation_generating",
    "pollCount": 9,
    "rephrasedQuestion": "List 5 customers from the olist_customers_dataset table.",
    "intentReasoning": "User wants to retrieve specific customer data, likely using SQL query.",
    "sqlGenerationReasoning": "1. **Identify the table involved**: The question asks for customer data, so the relevant table is `olist_customers_dataset`.\n\n2. **Determine the number of records needed**: The user requests 5 customers, so we need to select 5 entries from the table.",
    "retrievedTables": ["olist_customers_dataset"],
    "invalidSql": null,
    "traceId": "f218b1f7-4623-4a56-8b66-18d544797b20"
  },
  "timestamp": 1751014962254
}

data: {
  "type": "state",
  "data": {
    "state": "sql_generation_success",
    "sql": "SELECT \"o\".\"customer_id\", \"o\".\"customer_zip_code_prefix\", \"o\".\"customer_city\", \"o\".\"customer_state\" FROM \"olist_customers_dataset\" AS \"o\" LIMIT 5"
  },
  "timestamp": 1751014963263
}

data: {
  "type": "state",
  "data": {
    "state": "sql_execution_start",
    "sql": "SELECT \"o\".\"customer_id\", \"o\".\"customer_zip_code_prefix\", \"o\".\"customer_city\", \"o\".\"customer_state\" FROM \"olist_customers_dataset\" AS \"o\" LIMIT 5"
  },
  "timestamp": 1751014963263
}

data: {
  "type": "state",
  "data": {
    "state": "sql_execution_end"
  },
  "timestamp": 1751014963339
}

content_block_start

Purpose: Signals the beginning of a content block (e.g., summary generation).
Payload: Describes the block (usually text).

{
  "type": "content_block_start",
  "content_block": {
    "type": "text",
    "name": "summary_generation"
  }
}

content_block_delta

Purpose: Streams the actual content in parts (e.g., summary sentence by sentence).
Payload: Includes text_delta for partial content.

{
  "type": "content_block_delta",
  "delta": {
    "type": "text_delta",
    "text": "São Paulo (SP) leads with"
  }
}

content_block_stop

Purpose: Indicates the end of a streamed content block.

{
  "type": "content_block_stop"
}

message_stop

Purpose: Marks the end of the entire stream. Includes processing duration and threadId.

{
  "type": "message_stop",
  "data": {
    "threadId": "0625991d-1bba-407d-8ad4-dd0210172484",
    "duration": 11096
  }
}