Migrate to SmithDB-backed SDK methods

Context

In May 2026, we released SmithDB, a new observability database built for modern AI agents. SmithDB delivers industry-leading performance across every key observability workload, making core LangSmith experiences dramatically faster. SmithDB-powered methods are now available to SDK users in eligible regions.

Deployment support

Deployment	Status
US SaaS	Available. Methods are fully SmithDB-backed.
EU and other SaaS regions	Methods are available but not yet backed by SmithDB.
Self-hosted	Supported starting with self-hosted version 0.16.0.

Minimum SDK version

The SmithDB-backed methods require a minimum SDK version:

Language	Package	Minimum version
Python	`langsmith`	`>=0.10.2`
TypeScript	`langsmith`	`>=0.8.1`
Java	`langsmith-java`	`0.1.0-beta.11`
Go	`langsmith-go`	`v0.17.0`

Migrate with an AI agent

This guide is written to be fetched and applied directly by an AI coding agent. Copy the following prompt into your agent to migrate your codebase to the SmithDB-backed methods.

Migrate this codebase's LangSmith SDK usage to the new SmithDB-backed methods.

Fetch https://docs.langchain.com/langsmith/smithdb-sdk-migration.md and treat it
as the source of truth for what changed, including which methods and
parameters are affected, what replaces them, and deployment support.

1. Check the installed LangSmith SDK version against the minimum version
   required for the SmithDB-backed methods per the guide, and upgrade the
   dependency if it does not meet that minimum.
2. Identify every call site in this codebase that uses a method the guide
   marks as migrated, in whichever language(s) this codebase uses.
3. For each call site, apply the corresponding before/after change from the
   guide, including any added, removed, or renamed parameters.

If a call site or parameter is not covered by the guide, stop and ask rather
than guessing.

Exceptions

Python
TypeScript
Java
Go
cURL

The SmithDB-backed methods raise new exception classes instead of the legacy langsmith.utils exception classes.

Before (`langsmith.utils`)	After (`langsmith`)	Notes
`LangSmithError`	`LangsmithError`	Base exception class for the SDK; casing changed
`LangSmithAPIError`	`InternalServerError`	5xx
`LangSmithRequestTimeout`	`APITimeoutError`	Raised when a request times out
`LangSmithUserError`	(removed)	No direct equivalent. The 403 org-scoped-key case now raises `PermissionDeniedError`; client-side argument validation now raises a standard `ValueError` or `TypeError`
`LangSmithRateLimitError`	`RateLimitError`	429; unchanged name
`LangSmithAuthError`	`AuthenticationError`	401
`LangSmithNotFoundError`	`NotFoundError`	404; unchanged name
`LangSmithConflictError`	`ConflictError`	409; unchanged name
`LangSmithConnectionError`	`APIConnectionError`	Raised when the client cannot connect to the API
`LangSmithExceptionGroup`	(removed)	No equivalent
(not available)	`APIError`	New: base class for all API-related errors, with `message`, `request`, and `body` attributes
(not available)	`APIStatusError`	New: base class for all 4xx/5xx status errors
(not available)	`BadRequestError`	New: 400
(not available)	`PermissionDeniedError`	New: 403
(not available)	`UnprocessableEntityError`	New: 422
(not available)	`APIResponseValidationError`	New: raised when a response does not match the expected schema

The SmithDB-backed methods raise new exception classes instead of plain Error.

Before (plain `Error`)	After (`langsmith`)	Notes
(not available)	`LangsmithError`	base class for all SDK errors
(not available)	`InternalServerError`	5xx
(not available)	`APIConnectionTimeoutError`	Raised when a request times out
(not available)	`RateLimitError`	429
(not available)	`AuthenticationError`	401
(not available)	`NotFoundError`	404
(not available)	`ConflictError`	409
(not available)	`APIConnectionError`	Raised when the client cannot connect to the API
(not available)	`APIError`	base class for all API-related errors, with `status`, `headers`, and `error` properties
(not available)	`BadRequestError`	400
(not available)	`PermissionDeniedError`	403
(not available)	`UnprocessableEntityError`	422
(not available)	`APIUserAbortError`	Raised when a request is aborted via an `AbortController`

Runs: query

Query runs from a project with optional filtering and field projection. Returns a paginated result set.

Main changes

Method name

Python
TypeScript
Java
Go
cURL

Before	After
`client.list_runs()`	`client.runs.query()`

client.runs.query() is now async. Call it with await.

Before	After
`client.listRuns()`	`client.runs.query()`

Before	After
`client.runs().query()`	`client.runs().queryV2()`

Before	After
`client.Runs.Query()`	`client.Runs.QueryV2()`

Before	After
`POST /api/v1/runs/query`	`POST /v2/runs/query`

Query parameters

Python
TypeScript
Java
Go
cURL

project_name is not supported in runs.query. Pass project_ids with the project UUID instead. To look up a UUID by name, use client.read_project(project_name="my-project"), or await client.aread_project(project_name="my-project") in async code.

min_start_time defaults to 1 day ago when omitted. list_runs with no start_time returned all historical runs; runs.query without min_start_time silently scopes the query to the last 24 hours. Pass an explicit min_start_time if you need a wider window.

Before (`list_runs`)	After (`runs.query`)	Notes
`project_name`	(removed)	Use `project_ids` with UUID(s)—see warning above
`project_id`	`project_ids`	Now takes a list; mutually exclusive with `reference_dataset_id`
`run_type`	`run_type`	Values must now be uppercase: `"LLM"`, `"CHAIN"`, `"TOOL"`, `"RETRIEVER"`, `"EMBEDDING"`, `"PROMPT"`, `"PARSER"`
`trace_id`	`trace_id`	Unchanged
`reference_example_id`	`reference_examples`	Now takes a list of UUIDs
`query`	(removed)	No equivalent
`filter`	`filter`	Syntax unchanged
`trace_filter`	`trace_filter`	Unchanged
`tree_filter`	`tree_filter`	Unchanged
`is_root`	`is_root`	Unchanged
`parent_run_id`	(removed)	No equivalent
`start_time`	`min_start_time`	Renamed; defaults to 1 day ago—see warning above
`error`	`has_error`	Renamed
`run_ids`	`ids`	Renamed
`select`	`selects`	Field names are now uppercase (`"NAME"`, `"STATUS"`, etc.)
`limit`	(removed)	Use `page_size` for per-request batch size
(not available)	`max_start_time`	Upper bound for `start_time`; defaults to now
(not available)	`page_size`	Per-request result count (default 100, max 1000)
(not available)	`reference_dataset_id`	Alternative to `project_ids`; mutually exclusive
(not available)	`cursor`	Pass `next_cursor` from previous response to fetch next page

projectName is not supported in client.runs.query. Pass project_ids with the project UUID instead. To look up a UUID by name, use client.readProject({ projectName: "my-project" }).

min_start_time defaults to 1 day ago when omitted. listRuns with no startTime returned all historical runs; client.runs.query without min_start_time silently scopes the query to the last 24 hours. Pass an explicit min_start_time if you need a wider window.

Before (`listRuns`)	After (`client.runs.query`)	Notes
`projectName`	(removed)	Use `project_ids` with UUID(s)—see warning above
`projectId`	`project_ids`	Renamed to `snake_case`; now takes a list; mutually exclusive with `reference_dataset_id`
`runType`	`run_type`	Renamed to `snake_case`; values must now be uppercase: `"LLM"`, `"CHAIN"`, `"TOOL"`, `"RETRIEVER"`, `"EMBEDDING"`, `"PROMPT"`, `"PARSER"`
`traceId`	`trace_id`	Renamed to `snake_case`
`referenceExampleId`	`reference_examples`	Renamed to `snake_case`; now takes a list of UUIDs
`query`	(removed)	No equivalent
`filter`	`filter`	Syntax unchanged
`traceFilter`	`trace_filter`	Renamed to `snake_case`
`treeFilter`	`tree_filter`	Renamed to `snake_case`
`isRoot`	`is_root`	Renamed to `snake_case`
`parentRunId`	(removed)	No equivalent
`startTime`	`min_start_time`	Renamed to `snake_case`; defaults to 1 day ago—see warning above
`error`	`has_error`	Renamed
`id`	`ids`	Renamed
`select`	`selects`	Field names are now uppercase (`"NAME"`, `"STATUS"`, etc.)
`limit`	(removed)	Use `page_size` for per-request batch size
`order`	(removed)	No equivalent
`executionOrder`	(removed)	No equivalent
(not available)	`max_start_time`	Upper bound for `start_time`; defaults to now
(not available)	`page_size`	Per-request result count (default 100, max 1000)
(not available)	`reference_dataset_id`	Alternative to `project_ids`; mutually exclusive
(not available)	`cursor`	Pass `next_cursor` from previous response to fetch next page

minStartTime() defaults to 1 day ago when omitted. query() with no startTime() returned all historical runs; queryV2() without minStartTime() silently scopes the query to the last 24 hours. Pass an explicit minStartTime() if you need a wider window.

Before (`RunQueryParams`)	After (`RunQueryV2Params`)	Notes
`session()`	`projectIds()`	Renamed; now takes explicit project UUIDs
`runType()`	`runType()`	Values must now be uppercase
`trace()`	`traceId()`	Renamed
`referenceExample()`	`referenceExamples()`	Renamed to plural
`query()`	(removed)	No equivalent
`filter()`	`filter()`	Syntax unchanged
`traceFilter()`	`traceFilter()`	Unchanged
`treeFilter()`	`treeFilter()`	Unchanged
`isRoot()`	`isRoot()`	Unchanged
`parentRun()`	(removed)	No equivalent
`startTime()`	`minStartTime()`	Renamed; defaults to 1 day ago—see warning above
`error()`	`hasError()`	Renamed
`id()`	`ids()`	Renamed
`select()`	`selects()`	Field names are now uppercase
`limit()`	(removed)	Use `pageSize()`
`order()`	(removed)	No equivalent
`executionOrder()`	(removed)	No equivalent
`cursor()`	`cursor()`	Unchanged
(not available)	`maxStartTime()`	Upper bound for start time; defaults to now
(not available)	`pageSize()`	Per-request result count (default 100, max 1000)
(not available)	`referenceDatasetId()`	Alternative to `projectIds()`

MinStartTime defaults to 1 day ago when omitted. Query() with no StartTime returned all historical runs; QueryV2() without MinStartTime silently scopes the query to the last 24 hours. Pass an explicit MinStartTime if you need a wider window.

Before (`RunQueryParams`)	After (`RunQueryV2Params`)	Notes
`Session`	`ProjectIDs`	Renamed; now takes explicit project UUIDs
`RunType`	`RunType`	Values must now be uppercase: `RunQueryV2ParamsRunTypeLLM`, `RunQueryV2ParamsRunTypeChain`, etc.
`Trace`	`TraceID`	Renamed
`ReferenceExample`	`ReferenceExamples`	Renamed to plural
`Query`	(removed)	No equivalent
`Filter`	`Filter`	Unchanged
`TraceFilter`	`TraceFilter`	Unchanged
`TreeFilter`	`TreeFilter`	Unchanged
`IsRoot`	`IsRoot`	Unchanged
`ParentRun`	(removed)	No equivalent
`StartTime`	`MinStartTime`	Renamed; defaults to 1 day ago—see warning above
`Error`	`HasError`	Renamed
`ID`	`IDs`	Renamed
`Select`	`Selects`	Field name constants are now uppercase (e.g., `RunQueryV2ParamsSelectName`)
`Limit`	(removed)	Use `PageSize`
`Order`	(removed)	No equivalent
`ExecutionOrder`	(removed)	No equivalent
`Cursor`	`Cursor`	Unchanged
(not available)	`MaxStartTime`	Upper bound for start time; defaults to now
(not available)	`PageSize`	Per-request result count (default 100, max 1000)
(not available)	`ReferenceDatasetID`	Alternative to `ProjectIDs`

min_start_time defaults to 1 day ago when omitted. POST /api/v1/runs/query with no start_time returned all historical runs; POST /v2/runs/query without min_start_time silently scopes the query to the last 24 hours. Pass an explicit min_start_time if you need a wider window.

Before (v1 `POST /api/v1/runs/query` body field)	After (v2 `POST /v2/runs/query` body field)	Notes
`session`	`project_ids`	Renamed; both take an array of project UUIDs. `project_ids` is mutually exclusive with `reference_dataset_id`
`run_type`	`run_type`	Values must now be uppercase: `"LLM"`, `"CHAIN"`, `"TOOL"`, `"RETRIEVER"`, `"EMBEDDING"`, `"PROMPT"`, `"PARSER"`
`trace`	`trace_id`	Renamed
`reference_example`	`reference_examples`	Renamed to plural; now takes an array of UUIDs
`query`	(removed)	No equivalent
`filter`	`filter`	Syntax unchanged
`trace_filter`	`trace_filter`	Unchanged
`tree_filter`	`tree_filter`	Unchanged
`is_root`	`is_root`	Unchanged
`parent_run`	(removed)	No equivalent
`start_time`	`min_start_time`	Renamed; defaults to 1 day ago—see warning above
`error`	`has_error`	Renamed
`id`	`ids`	Renamed to plural
`select`	`selects`	Field names are now uppercase (`"NAME"`, `"STATUS"`, etc.)
`limit`	(removed)	Use `page_size` for per-request batch size
(not available)	`max_start_time`	Upper bound for `start_time`; defaults to now
(not available)	`page_size`	Per-request result count (default 100, max 1000)
(not available)	`reference_dataset_id`	Alternative to `project_ids`; mutually exclusive
(not available)	`cursor`	Pass `next_cursor` from previous response to fetch next page

Response fields

Python
TypeScript
Java
Go
cURL

Pass SCREAMING_SNAKE_CASE strings to selects (eg. "ID", "NAME", "STATUS") to control which fields are populated on each Run; only selected fields are non-None. Default selects contains only "ID".

Before (v1 `Run` attribute)	After (v2 `Run` attribute)	Notes
`run.id`	`run.id`	Unchanged; returned by default when `selects` is omitted
`run.name`	`run.name`	Unchanged
`run.run_type`	`run.run_type`	Values are now uppercase Literals: `"LLM"`, `"CHAIN"`, etc.
`run.status`	`run.status`	Values: `"SUCCESS"`, `"ERROR"`, `"PENDING"`
`run.start_time`	`run.start_time`	Unchanged
`run.end_time`	`run.end_time`	Unchanged
`run.error`	`run.error`	Unchanged
`run.inputs`	`run.inputs`	Unchanged
`run.outputs`	`run.outputs`	Unchanged
`run.tags`	`run.tags`	Unchanged
`run.extra`	`run.extra`	Unchanged
`run.metadata`	`run.metadata`	Unchanged
`run.events`	`run.events`	Unchanged
`run.reference_example_id`	`run.reference_example_id`	Unchanged
`run.trace_id`	`run.trace_id`	Unchanged
`run.dotted_order`	`run.dotted_order`	Unchanged
`run.parent_run_id`	(removed)	Use `run.parent_run_ids` (list of all ancestor UUIDs, root first)
`run.parent_run_ids`	`run.parent_run_ids`	Unchanged
`run.session_id`	`run.project_id`	Renamed; `session_id` was the project UUID
`run.feedback_stats`	`run.feedback_stats`	Unchanged
`run.app_path`	`run.app_path`	Unchanged
`run.attachments`	`run.attachments`	v2 returns pre-signed download URLs instead of raw bytes
`run.total_tokens`	`run.total_tokens`	Unchanged
`run.prompt_tokens`	`run.prompt_tokens`	Unchanged
`run.completion_tokens`	`run.completion_tokens`	Unchanged
`run.total_cost`	`run.total_cost`	Unchanged
`run.prompt_cost`	`run.prompt_cost`	Unchanged
`run.completion_cost`	`run.completion_cost`	Unchanged
`run.first_token_time`	`run.first_token_time`	Unchanged
`run.latency` (property)	`run.latency_seconds`	Renamed; was a computed `timedelta` property, now a native `float` field
`run.in_dataset`	`run.is_in_dataset`	Renamed
`run.child_run_ids`	(removed)	No equivalent
`run.child_runs`	(removed)	No equivalent
`run.serialized`	(removed)	Use `run.manifest`
`run.manifest_id`	(removed)	Use `run.manifest`
(not available)	`run.is_root`	New
(not available)	`run.manifest`	New: full manifest object (replaces `serialized` and `manifest_id`)
(not available)	`run.error_preview`	New: truncated error snippet
(not available)	`run.inputs_preview`	New: truncated inputs preview
(not available)	`run.outputs_preview`	New: truncated outputs preview
(not available)	`run.thread_id`	New: conversation thread UUID
(not available)	`run.reference_dataset_id`	New: dataset UUID for the reference example
(not available)	`run.share_url`	New: public share URL (only set when the run has been shared)
`run.prompt_token_details`	`run.prompt_token_details.raw`	Field now wraps the dict; access `.raw` to get `dict[str, int]` (element type unchanged)
`run.completion_token_details`	`run.completion_token_details.raw`	Field now wraps the dict; access `.raw` to get `dict[str, int]` (element type unchanged)
`run.prompt_cost_details`	`run.prompt_cost_details.raw`	Field now wraps the dict; access `.raw` to get `dict[str, float]` (was `dict[str, Decimal]`)
`run.completion_cost_details`	`run.completion_cost_details.raw`	Field now wraps the dict; access `.raw` to get `dict[str, float]` (was `dict[str, Decimal]`)

Pass SCREAMING_SNAKE_CASE strings to selects (eg. "ID", "NAME", "STATUS") to control which fields are populated on each Run. Default selects contains only "ID".

Before (v1 `Run` property)	After (v2 `Run` property)	Notes
`run.id`	`run.id`	Unchanged
`run.name`	`run.name`	Unchanged
`run.runType`	`run.run_type`	Renamed to `snake_case`; values are now uppercase: `"LLM"`, `"CHAIN"`, etc.
`run.status`	`run.status`	Values: `"SUCCESS"`, `"ERROR"`, `"PENDING"`
`run.startTime`	`run.start_time`	Renamed to `snake_case`
`run.endTime`	`run.end_time`	Renamed to `snake_case`
`run.error`	`run.error`	Unchanged
`run.inputs`	`run.inputs`	Unchanged
`run.outputs`	`run.outputs`	Unchanged
`run.tags`	`run.tags`	Unchanged
`run.extra`	`run.extra`	Unchanged
(not available)	`run.metadata`	New: previously accessed via `run.extra.metadata`
`run.events`	`run.events`	Unchanged
`run.referenceExampleId`	`run.reference_example_id`	Renamed to `snake_case`
`run.traceId`	`run.trace_id`	Renamed to `snake_case`
`run.dottedOrder`	`run.dotted_order`	Renamed to `snake_case`
`run.parentRunId`	(removed)	Use `run.parent_run_ids` (list of all ancestor UUIDs, root first)
`run.parentRunIds`	`run.parent_run_ids`	Renamed to `snake_case`
`run.sessionId`	`run.project_id`	Renamed; `sessionId` was the project UUID
`run.feedbackStats`	`run.feedback_stats`	Renamed to `snake_case`
`run.appPath`	`run.app_path`	Renamed to `snake_case`
`run.attachments`	`run.attachments`	v2 returns pre-signed download URLs instead of raw bytes
`run.totalTokens`	`run.total_tokens`	Renamed to `snake_case`
`run.promptTokens`	`run.prompt_tokens`	Renamed to `snake_case`
`run.completionTokens`	`run.completion_tokens`	Renamed to `snake_case`
`run.totalCost`	`run.total_cost`	Renamed to `snake_case`
`run.promptCost`	`run.prompt_cost`	Renamed to `snake_case`
`run.completionCost`	`run.completion_cost`	Renamed to `snake_case`
`run.firstTokenTime`	`run.first_token_time`	Renamed to `snake_case`
`run.latency`	`run.latency_seconds`	Renamed; was a computed property, now a native `number` field (seconds)
`run.inDataset`	`run.is_in_dataset`	Renamed
`run.childRunIds`	(removed)	No equivalent
`run.childRuns`	(removed)	No equivalent
`run.serialized`	(removed)	Use `run.manifest`
`run.manifestId`	(removed)	Use `run.manifest`
`run.shareToken`	(removed)	Use `run.share_url` (full URL, only set when the run has been shared)
(not available)	`run.is_root`	New
(not available)	`run.manifest`	New: full manifest object (replaces `serialized` and `manifestId`)
(not available)	`run.error_preview`	New: truncated error snippet
(not available)	`run.inputs_preview`	New: truncated inputs preview
(not available)	`run.outputs_preview`	New: truncated outputs preview
(not available)	`run.thread_id`	New: conversation thread UUID
(not available)	`run.reference_dataset_id`	New: dataset UUID for the reference example
(not available)	`run.share_url`	New: public share URL (only set when the run has been shared)
(not available)	`run.prompt_token_details`	New: per-category prompt token breakdown
(not available)	`run.completion_token_details`	New: per-category completion token breakdown
(not available)	`run.prompt_cost_details`	New: per-category prompt cost breakdown
(not available)	`run.completion_cost_details`	New: per-category completion cost breakdown

Add RunQueryV2Params.Select values (eg. Select.NAME, Select.STATUS) via .addSelect(...) to control which fields are populated; unselected fields return empty Optional values. selects() defaults to ID only.

Before (`RunSchema` method)	After (`Run` method)	Notes
`run.id()`	`run.id()`	Unchanged
`run.name()`	`run.name()`	Unchanged
`run.runType()`	`run.runType()`	Values are now uppercase: `"LLM"`, `"CHAIN"`, etc.
`run.status()`	`run.status()`	Values: `"SUCCESS"`, `"ERROR"`, `"PENDING"`
`run.startTime()`	`run.startTime()`	Unchanged
`run.endTime()`	`run.endTime()`	Unchanged
`run.error()`	`run.error()`	Unchanged
`run.inputs()`	`run.inputs()`	Unchanged
`run.outputs()`	`run.outputs()`	Unchanged
`run.tags()`	`run.tags()`	Unchanged
`run.extra()`	`run.extra()`	Unchanged
`run.events()`	`run.events()`	Unchanged
`run.feedbackStats()`	`run.feedbackStats()`	Unchanged
`run.inputsPreview()`	`run.inputsPreview()`	Unchanged
`run.outputsPreview()`	`run.outputsPreview()`	Unchanged
`run.referenceExampleId()`	`run.referenceExampleId()`	Unchanged
`run.traceId()`	`run.traceId()`	Unchanged
`run.dottedOrder()`	`run.dottedOrder()`	Unchanged
`run.parentRunId()`	(removed)	Use `run.parentRunIds()` (list of all ancestor UUIDs, root first)
`run.parentRunIds()`	`run.parentRunIds()`	Unchanged
`run.sessionId()`	`run.projectId()`	Renamed; `sessionId()` returned the project UUID
`run.appPath()`	`run.appPath()`	Unchanged
`run.firstTokenTime()`	`run.firstTokenTime()`	Unchanged
`run.totalTokens()`	`run.totalTokens()`	Unchanged
`run.promptTokens()`	`run.promptTokens()`	Unchanged
`run.completionTokens()`	`run.completionTokens()`	Unchanged
`run.totalCost()`	`run.totalCost()`	Return type changed from `Optional<String>` to `Optional<Double>`
`run.promptCost()`	`run.promptCost()`	Return type changed from `Optional<String>` to `Optional<Double>`
`run.completionCost()`	`run.completionCost()`	Return type changed from `Optional<String>` to `Optional<Double>`
`run.promptTokenDetails()`	`run.promptTokenDetails()`	Unchanged
`run.completionTokenDetails()`	`run.completionTokenDetails()`	Unchanged
`run.promptCostDetails()`	`run.promptCostDetails()`	Unchanged
`run.completionCostDetails()`	`run.completionCostDetails()`	Unchanged
`run.priceModelId()`	`run.priceModelId()`	Unchanged
`run.inDataset()`	`run.isInDataset()`	Renamed
`run.referenceDatasetId()`	`run.referenceDatasetId()`	Unchanged
`run.threadId()`	`run.threadId()`	Unchanged
`run.shareToken()`	(removed)	Use `run.shareUrl()` (full URL, only set when the run has been shared)
`run.childRunIds()`	(removed)	No equivalent
`run.directChildRunIds()`	(removed)	No equivalent
`run.serialized()`	(removed)	Use `run.manifest()`
`run.manifestId()`	(removed)	Use `run.manifest()`
`run.messages()`	(removed)	No equivalent
`run.executionOrder()`	(removed)	No equivalent
`run.lastQueuedAt()`	(removed)	No equivalent
`run.traceFirstReceivedAt()`	(removed)	No equivalent
`run.traceMaxStartTime()`	(removed)	No equivalent
`run.traceMinStartTime()`	(removed)	No equivalent
`run.traceTier()`	(removed)	No equivalent
`run.traceUpgrade()`	(removed)	No equivalent
`run.ttlSeconds()`	(removed)	No equivalent
(not available)	`run.attachments()`	New: pre-signed download URLs for attachments (replaces S3 URL fields)
(not available)	`run.latencySeconds()`	New: wall-clock duration in seconds
(not available)	`run.isRoot()`	New
(not available)	`run.errorPreview()`	New: truncated error snippet
(not available)	`run.manifest()`	New: full manifest, typed as `Optional<Manifest>` (replaces `serialized()` and `manifestId()`)
(not available)	`run.metadata()`	New: metadata, typed as `Optional<Metadata>` (was derived from `extra.metadata`)
(not available)	`run.shareUrl()`	New: public share URL (only set when the run has been shared)
(not available)	`run.threadEvaluationTime()`	New

Pass RunQueryV2ParamsSelect constants (eg. RunQueryV2ParamsSelectName, RunQueryV2ParamsSelectStatus) to Selects to control which fields are populated; unselected fields are zero-valued on the returned struct. Selects defaults to ID only.

Before (`RunSchema` field)	After (`Run` field)	Notes
`run.ID`	`run.ID`	Unchanged
`run.Name`	`run.Name`	Unchanged
`run.RunType`	`run.RunType`	Values changed to uppercase: `"LLM"`, `"CHAIN"`, etc.
`run.Status`	`run.Status`	Values: `"SUCCESS"`, `"ERROR"`, `"PENDING"`
`run.TraceID`	`run.TraceID`	Unchanged
`run.DottedOrder`	`run.DottedOrder`	Unchanged
`run.AppPath`	`run.AppPath`	Unchanged
`run.StartTime`	`run.StartTime`	Unchanged
`run.EndTime`	`run.EndTime`	Unchanged
`run.Error`	`run.Error`	Unchanged
`run.Events`	`run.Events`	Unchanged; element type is now `RunEvent` (was `map[string]interface{}`)
`run.Extra`	`run.Extra`	Unchanged; type is now `interface{}` (was `map[string]interface{}`)
`run.FeedbackStats`	`run.FeedbackStats`	Unchanged; element type is now `RunFeedbackStat`
`run.FirstTokenTime`	`run.FirstTokenTime`	Unchanged
`run.Inputs`	`run.Inputs`	Unchanged; type is now `interface{}` (was `map[string]interface{}`)
`run.InputsPreview`	`run.InputsPreview`	Unchanged
`run.Outputs`	`run.Outputs`	Unchanged; type is now `interface{}` (was `map[string]interface{}`)
`run.OutputsPreview`	`run.OutputsPreview`	Unchanged
`run.ParentRunIDs`	`run.ParentRunIDs`	Unchanged
`run.PriceModelID`	`run.PriceModelID`	Unchanged
`run.PromptCost`	`run.PromptCost`	Unchanged
`run.PromptCostDetails`	`run.PromptCostDetails.Raw`	Field now wraps the map; access `.Raw` to get `map[string]float64` (was `map[string]string`)
`run.PromptTokenDetails`	`run.PromptTokenDetails.Raw`	Field now wraps the map; access `.Raw` to get `map[string]int64` (element type unchanged)
`run.PromptTokens`	`run.PromptTokens`	Unchanged
`run.CompletionCost`	`run.CompletionCost`	Unchanged
`run.CompletionCostDetails`	`run.CompletionCostDetails.Raw`	Field now wraps the map; access `.Raw` to get `map[string]float64` (was `map[string]string`)
`run.CompletionTokenDetails`	`run.CompletionTokenDetails.Raw`	Field now wraps the map; access `.Raw` to get `map[string]int64` (element type unchanged)
`run.CompletionTokens`	`run.CompletionTokens`	Unchanged
`run.TotalCost`	`run.TotalCost`	Unchanged
`run.TotalTokens`	`run.TotalTokens`	Unchanged
`run.ReferenceDatasetID`	`run.ReferenceDatasetID`	Unchanged
`run.ReferenceExampleID`	`run.ReferenceExampleID`	Unchanged
`run.Tags`	`run.Tags`	Unchanged
`run.ThreadID`	`run.ThreadID`	Unchanged
`run.SessionID`	`run.ProjectID`	Renamed
`run.InDataset`	`run.IsInDataset`	Renamed
`run.ChildRunIDs`	(removed)	No equivalent
`run.DirectChildRunIDs`	(removed)	No equivalent
`run.ExecutionOrder`	(removed)	No equivalent
`run.InputsS3URLs`	(removed)	Internal storage URL; not exposed in v2
`run.LastQueuedAt`	(removed)	No equivalent
`run.ManifestID`	(removed)	Use `run.Manifest`
`run.ManifestS3ID`	(removed)	Internal storage URL; not exposed in v2
`run.Messages`	(removed)	No equivalent
`run.OutputsS3URLs`	(removed)	Internal storage URL; not exposed in v2
`run.ParentRunID`	(removed)	Use `run.ParentRunIDs`
`run.S3URLs`	(removed)	Internal storage URL; not exposed in v2
`run.Serialized`	(removed)	Use `run.Manifest`
`run.ShareToken`	(removed)	Use `run.ShareURL`
`run.TraceFirstReceivedAt`	(removed)	No equivalent
`run.TraceMaxStartTime`	(removed)	No equivalent
`run.TraceMinStartTime`	(removed)	No equivalent
`run.TraceTier`	(removed)	No equivalent
`run.TraceUpgrade`	(removed)	No equivalent
`run.TtlSeconds`	(removed)	No equivalent
(not available)	`run.Attachments`	New: maps attachment filename to pre-signed download URL
(not available)	`run.ErrorPreview`	New: truncated error snippet
(not available)	`run.IsRoot`	New
(not available)	`run.LatencySeconds`	New: wall-clock duration in seconds
(not available)	`run.Manifest`	New: full manifest object (replaces `Serialized` and `ManifestID`)
(not available)	`run.Metadata`	New: arbitrary user-defined JSON metadata
(not available)	`run.ShareURL`	New: public share URL (only set when the run has been shared)
(not available)	`run.ThreadEvaluationTime`	New

Field names in the JSON response match Python snake_case.Pass SCREAMING_SNAKE_CASE strings in the selects JSON array (eg. "ID", "NAME", "STATUS") to control which fields are populated. Default selects contains only "ID".

Before (v1 response field)	After (v2 response field)	Notes
`id`	`id`	Unchanged
`name`	`name`	Unchanged
`run_type`	`run_type`	Values changed to uppercase: `"LLM"`, `"CHAIN"`, etc.
`status`	`status`	Values: `"SUCCESS"`, `"ERROR"`, `"PENDING"`
`trace_id`	`trace_id`	Unchanged
`dotted_order`	`dotted_order`	Unchanged
`app_path`	`app_path`	Unchanged
`start_time`	`start_time`	Unchanged
`end_time`	`end_time`	Unchanged
`error`	`error`	Unchanged
`events`	`events`	Unchanged
`extra`	`extra`	Unchanged
`feedback_stats`	`feedback_stats`	Unchanged
`first_token_time`	`first_token_time`	Unchanged
`inputs`	`inputs`	Unchanged
`inputs_preview`	`inputs_preview`	Unchanged
`outputs`	`outputs`	Unchanged
`outputs_preview`	`outputs_preview`	Unchanged
`parent_run_ids`	`parent_run_ids`	Unchanged
`price_model_id`	`price_model_id`	Unchanged
`prompt_cost`	`prompt_cost`	Unchanged
`prompt_cost_details`	`prompt_cost_details.raw`	Field now wraps the object; read `.raw` for the same `{category: cost}` mapping, now with numeric values (was strings)
`prompt_token_details`	`prompt_token_details.raw`	Field now wraps the object; read `.raw` for the same `{category: count}` mapping (values unchanged)
`prompt_tokens`	`prompt_tokens`	Unchanged
`completion_cost`	`completion_cost`	Unchanged
`completion_cost_details`	`completion_cost_details.raw`	Field now wraps the object; read `.raw` for the same `{category: cost}` mapping, now with numeric values (was strings)
`completion_token_details`	`completion_token_details.raw`	Field now wraps the object; read `.raw` for the same `{category: count}` mapping (values unchanged)
`completion_tokens`	`completion_tokens`	Unchanged
`total_cost`	`total_cost`	Unchanged
`total_tokens`	`total_tokens`	Unchanged
`reference_dataset_id`	`reference_dataset_id`	Unchanged
`reference_example_id`	`reference_example_id`	Unchanged
`tags`	`tags`	Unchanged
`thread_id`	`thread_id`	Unchanged
`session_id`	`project_id`	Renamed
`in_dataset`	`is_in_dataset`	Renamed
`child_run_ids`	(removed)	No equivalent
`direct_child_run_ids`	(removed)	No equivalent
`execution_order`	(removed)	No equivalent
`inputs_s3_urls`	(removed)	Internal storage URL; not exposed in v2
`last_queued_at`	(removed)	No equivalent
`manifest_id`	(removed)	Use `manifest`
`manifest_s3_id`	(removed)	Internal storage URL; not exposed in v2
`messages`	(removed)	No equivalent
`outputs_s3_urls`	(removed)	Internal storage URL; not exposed in v2
`parent_run_id`	(removed)	Use `parent_run_ids`
`s3_urls`	(removed)	Internal storage URL; not exposed in v2
`serialized`	(removed)	Use `manifest`
`share_token`	(removed)	Use `share_url`
`trace_first_received_at`	(removed)	No equivalent
`trace_max_start_time`	(removed)	No equivalent
`trace_min_start_time`	(removed)	No equivalent
`trace_tier`	(removed)	No equivalent
`trace_upgrade`	(removed)	No equivalent
`ttl_seconds`	(removed)	No equivalent
(not available)	`attachments`	New: maps attachment filename to pre-signed download URL
(not available)	`error_preview`	New: truncated error snippet
(not available)	`is_root`	New
(not available)	`latency_seconds`	New: wall-clock duration in seconds
(not available)	`manifest`	New: full manifest object (replaces `serialized` and `manifest_id`)
(not available)	`metadata`	New: previously nested under `extra.metadata`
(not available)	`share_url`	New: public share URL (only set when the run has been shared)
(not available)	`thread_evaluation_time`	New

Examples

List all runs in a project

Python
TypeScript
Java
Go
cURL

runs.query does not accept a project name directly. Resolve the project UUID with client.aread_project() first, then pass it as a string in project_ids.

Before
After

Before

from langsmith import Client

client = Client()
runs = client.list_runs(project_name="default")

After

import asyncio

from langsmith import Client

async def main():
    client = Client()
    project = await client.aread_project(project_name="default")
    runs = client.runs.query(project_ids=[str(project.id)])

asyncio.run(main())

client.runs.query does not accept a project name directly. Resolve the project UUID with client.readProject() first, then pass it as a string in project_ids.

Before
After

Before

import { Client } from "langsmith";

const client = new Client();
const runs = client.listRuns({ projectName: "default" });

After

import { Client } from "langsmith";

const client = new Client();
const project = await client.readProject({ projectName: "default" });
const runs = client.runs.query({ project_ids: [project.id] });

queryV2() does not accept a project name directly. Resolve the project UUID with client.sessions().list() first, then pass it as a string in projectIds().

Before
After

Before

import com.langchain.smith.client.LangsmithClient
import com.langchain.smith.client.okhttp.LangsmithOkHttpClient
import com.langchain.smith.models.runs.RunQueryParams
import com.langchain.smith.models.sessions.SessionListParams

val client: LangsmithClient = LangsmithOkHttpClient.fromEnv()

val project = client.sessions().list(
    SessionListParams.builder().name("default").limit(1L).build()
).items().first()
val runs = client.runs().query(
    RunQueryParams.builder().addSession(project.id()).build()
).items()

After

import com.langchain.smith.client.LangsmithClient
import com.langchain.smith.client.okhttp.LangsmithOkHttpClient
import com.langchain.smith.models.runs.RunQueryV2Params
import com.langchain.smith.models.sessions.SessionListParams

val client: LangsmithClient = LangsmithOkHttpClient.fromEnv()

val project = client.sessions().list(
    SessionListParams.builder().name("default").limit(1L).build()
).items().first()
val runs = client.runs().queryV2(
    RunQueryV2Params.builder().addProjectId(project.id()).build()
).items()

QueryV2() does not accept a project name directly. Resolve the project UUID with client.Sessions.List() first, then pass it as a string in ProjectIDs.

Before
After

Before

package main

import (
	"context"

	"github.com/langchain-ai/langsmith-go"
)

ctx := context.Background()
client := langsmith.NewClient()

sessions, err := client.Sessions.List(ctx, langsmith.SessionListParams{
	Name:  langsmith.F("default"),
	Limit: langsmith.F(int64(1)),
})
project := sessions.Items[0]

runs, err := client.Runs.Query(ctx, langsmith.RunQueryParams{
	Session: langsmith.F([]string{project.ID}),
})

After

package main

import (
	"context"

	"github.com/langchain-ai/langsmith-go"
)

ctx := context.Background()
client := langsmith.NewClient()

sessions, err := client.Sessions.List(ctx, langsmith.SessionListParams{
	Name:  langsmith.F("default"),
	Limit: langsmith.F(int64(1)),
})
project := sessions.Items[0]

runs, err := client.Runs.QueryV2(ctx, langsmith.RunQueryV2Params{
	ProjectIDs: langsmith.F([]string{project.ID}),
})

POST /v2/runs/query does not accept a project name directly. Resolve the project UUID with a GET /api/v1/sessions request first, then pass it as a string in project_ids.

Before
After

PROJECT_ID=$(curl -s "https://api.smith.langchain.com/api/v1/sessions?name=default&limit=1" \
  -H "x-api-key: $LANGSMITH_API_KEY" | jq -r '.[0].id')

curl -X POST "https://api.smith.langchain.com/api/v1/runs/query" \
  -H "x-api-key: $LANGSMITH_API_KEY" \
  -H "Content-Type: application/json" \
  -d "$(jq -n --arg pid "$PROJECT_ID" '{"session": [$pid]}')"

PROJECT_ID=$(curl -s "https://api.smith.langchain.com/api/v1/sessions?name=default&limit=1" \
  -H "x-api-key: $LANGSMITH_API_KEY" | jq -r '.[0].id')

curl -X POST "https://api.smith.langchain.com/v2/runs/query" \
  -H "x-api-key: $LANGSMITH_API_KEY" \
  -H "Content-Type: application/json" \
  -d "$(jq -n --arg pid "$PROJECT_ID" '{"project_ids": [$pid]}')"

Selecting fields

Python
TypeScript
Java
Go
cURL

list_runs returns a default set of fields with no selection needed. runs.query returns only id by default—pass selects=[...] to request more. Field names are now uppercase ("name" → "NAME").

Before
After

Before

from langsmith import Client

client = Client()
# returns a default set of fields; no explicit selection needed
runs = client.list_runs(project_name="default")
for run in runs:
    print(run.id, run.name, run.run_type, run.status, run.start_time, run.inputs, run.error)

After

import asyncio

from langsmith import Client


async def main():
    client = Client()
    project = await client.aread_project(project_name="default")
    # must explicitly list every field needed; default returns only id
    async for run in client.runs.query(
        project_ids=[str(project.id)],
        selects=["ID", "NAME", "RUN_TYPE", "STATUS", "START_TIME", "INPUTS", "ERROR"],
    ):
        print(run.id, run.name, run.run_type, run.status, run.start_time, run.inputs, run.error)


asyncio.run(main())

listRuns returns a default set of fields with no selection needed. client.runs.query returns only id by default—pass selects: [...] to request more. Field names are now uppercase ("name" → "NAME").

Before
After

Before

import { Client } from "langsmith";

const client = new Client();
// returns a default set of fields; no explicit selection needed
const runs = client.listRuns({ projectName: "default" });
for await (const run of runs) {
  console.log(run.id, run.name, run.run_type, run.status, run.start_time, run.inputs, run.error);
}

After

import { Client } from "langsmith";

const client = new Client();
const project = await client.readProject({ projectName: "default" });
// must explicitly list every field needed; default returns only id
for await (const run of client.runs.query({
  project_ids: [project.id],
  selects: ["ID", "NAME", "RUN_TYPE", "STATUS", "START_TIME", "INPUTS", "ERROR"],
})) {
  console.log(run.id, run.name, run.run_type, run.status, run.start_time, run.inputs, run.error);
}

query() returns a default set of fields with no selection needed. queryV2() returns only id by default—call .addSelect(RunQueryV2Params.Select.X) for each field you need.

Before
After

Before

import com.langchain.smith.client.LangsmithClient
import com.langchain.smith.client.okhttp.LangsmithOkHttpClient
import com.langchain.smith.models.runs.RunQueryParams
import com.langchain.smith.models.sessions.SessionListParams

val client: LangsmithClient = LangsmithOkHttpClient.fromEnv()

val project = client.sessions().list(
    SessionListParams.builder().name("default").limit(1L).build()
).items().first()
// returns a default set of fields; no explicit selection needed
val runs = client.runs().query(
    RunQueryParams.builder().addSession(project.id()).build()
).items()
for (run in runs) {
    println("${run.id()} ${run.name()} ${run.runType()} ${run.status()} ${run.startTime()} ${run.inputs()} ${run.error()}")
}

After

import com.langchain.smith.client.LangsmithClient
import com.langchain.smith.client.okhttp.LangsmithOkHttpClient
import com.langchain.smith.models.runs.RunQueryV2Params
import com.langchain.smith.models.sessions.SessionListParams

val client: LangsmithClient = LangsmithOkHttpClient.fromEnv()

val project = client.sessions().list(
    SessionListParams.builder().name("default").limit(1L).build()
).items().first()
// must explicitly list every field needed; default returns only id
val runs = client.runs().queryV2(
    RunQueryV2Params.builder()
        .addProjectId(project.id())
        .addSelect(RunQueryV2Params.Select.ID)
        .addSelect(RunQueryV2Params.Select.NAME)
        .addSelect(RunQueryV2Params.Select.RUN_TYPE)
        .addSelect(RunQueryV2Params.Select.STATUS)
        .addSelect(RunQueryV2Params.Select.START_TIME)
        .addSelect(RunQueryV2Params.Select.INPUTS)
        .addSelect(RunQueryV2Params.Select.ERROR)
        .build()
).items()
for (run in runs) {
    println("${run.id()} ${run.name()} ${run.runType()} ${run.status()} ${run.startTime()} ${run.inputs()} ${run.error()}")
}

Query returns a default set of fields with no selection needed. QueryV2 returns only ID by default—pass Selects with the uppercase field constants you need (e.g. RunQueryV2ParamsSelectName).

Before
After

Before

package main

import (
	"context"
	"fmt"

	"github.com/langchain-ai/langsmith-go"
)

ctx := context.Background()
client := langsmith.NewClient()

sessions, err := client.Sessions.List(ctx, langsmith.SessionListParams{
	Name:  langsmith.F("default"),
	Limit: langsmith.F(int64(1)),
})
project := sessions.Items[0]

// returns a default set of fields; no explicit selection needed
runs, err := client.Runs.Query(ctx, langsmith.RunQueryParams{
	Session: langsmith.F([]string{project.ID}),
})
for _, run := range runs.Runs {
	fmt.Println(run.ID, run.Name, run.RunType, run.Status, run.StartTime, run.Inputs, run.Error)
}

After

package main

import (
	"context"
	"fmt"

	"github.com/langchain-ai/langsmith-go"
)

ctx := context.Background()
client := langsmith.NewClient()

sessions, err := client.Sessions.List(ctx, langsmith.SessionListParams{
	Name:  langsmith.F("default"),
	Limit: langsmith.F(int64(1)),
})
project := sessions.Items[0]

// must explicitly list every field needed; default returns only id
runs, err := client.Runs.QueryV2(ctx, langsmith.RunQueryV2Params{
	ProjectIDs: langsmith.F([]string{project.ID}),
	Selects: langsmith.F([]langsmith.RunQueryV2ParamsSelect{
		langsmith.RunQueryV2ParamsSelectID,
		langsmith.RunQueryV2ParamsSelectName,
		langsmith.RunQueryV2ParamsSelectRunType,
		langsmith.RunQueryV2ParamsSelectStatus,
		langsmith.RunQueryV2ParamsSelectStartTime,
		langsmith.RunQueryV2ParamsSelectInputs,
		langsmith.RunQueryV2ParamsSelectError,
	}),
})
for _, run := range runs.Items {
	fmt.Println(run.ID, run.Name, run.RunType, run.Status, run.StartTime, run.Inputs, run.Error)
}

POST /api/v1/runs/query returns a default set of fields with no selection needed. POST /v2/runs/query returns only id by default—pass selects with the uppercase field names you need (e.g. "NAME").

Before
After

PROJECT_ID=$(curl -s "https://api.smith.langchain.com/api/v1/sessions?name=default&limit=1" \
  -H "x-api-key: $LANGSMITH_API_KEY" | jq -r '.[0].id')

curl -X POST "https://api.smith.langchain.com/api/v1/runs/query" \
  -H "x-api-key: $LANGSMITH_API_KEY" \
  -H "Content-Type: application/json" \
  -d "$(jq -n --arg pid "$PROJECT_ID" '{"session": [$pid]}')"

PROJECT_ID=$(curl -s "https://api.smith.langchain.com/api/v1/sessions?name=default&limit=1" \
  -H "x-api-key: $LANGSMITH_API_KEY" | jq -r '.[0].id')

curl -X POST "https://api.smith.langchain.com/v2/runs/query" \
  -H "x-api-key: $LANGSMITH_API_KEY" \
  -H "Content-Type: application/json" \
  -d "$(jq -n --arg pid "$PROJECT_ID" '{"project_ids": [$pid], "selects": ["ID", "NAME", "RUN_TYPE", "STATUS", "START_TIME", "INPUTS", "ERROR"]}')"

Filter by run type and time range

Python
TypeScript
Java
Go
cURL

start_time is renamed to min_start_time, and run_type values are now uppercase ("llm" → "LLM").

Before
After

Before

from datetime import datetime, timedelta

from langsmith import Client

client = Client()
runs = client.list_runs(
    project_name="default",
    start_time=datetime.now() - timedelta(days=1),
    run_type="llm",
)

After

import asyncio
from datetime import datetime, timedelta

from langsmith import Client


async def main():
    client = Client()
    project = await client.aread_project(project_name="default")
    runs = client.runs.query(
        project_ids=[str(project.id)],
        min_start_time=datetime.now() - timedelta(days=1),
        run_type="LLM",
    )


asyncio.run(main())

startTime (camelCase) becomes min_start_time (snake_case, matching the v2 request body), and runType values are now uppercase ("llm" → "LLM").

Before
After

Before

import { Client } from "langsmith";

const client = new Client();
const runs = client.listRuns({
  projectName: "default",
  startTime: new Date(Date.now() - 24 * 60 * 60 * 1000),
  runType: "llm",
});

After

import { Client } from "langsmith";

const client = new Client();
const project = await client.readProject({ projectName: "default" });
const oneDayAgo = new Date(Date.now() - 24 * 60 * 60 * 1000);
const runs = client.runs.query({
  project_ids: [project.id],
  min_start_time: oneDayAgo.toISOString(),
  run_type: "LLM",
});

.startTime() is renamed to .minStartTime(), and .runType() now takes the new RunQueryV2Params.RunType enum instead of RunTypeEnum.

Before
After

Before

import java.time.OffsetDateTime

import com.langchain.smith.client.LangsmithClient
import com.langchain.smith.client.okhttp.LangsmithOkHttpClient
import com.langchain.smith.models.runs.RunQueryParams
import com.langchain.smith.models.runs.RunTypeEnum
import com.langchain.smith.models.sessions.SessionListParams

val client: LangsmithClient = LangsmithOkHttpClient.fromEnv()

val project = client.sessions().list(
    SessionListParams.builder().name("default").limit(1L).build()
).items().first()
val runs = client.runs().query(
    RunQueryParams.builder()
        .addSession(project.id())
        .startTime(OffsetDateTime.now().minusDays(1))
        .runType(RunTypeEnum.LLM)
        .build()
).items()

After

import java.time.OffsetDateTime

import com.langchain.smith.client.LangsmithClient
import com.langchain.smith.client.okhttp.LangsmithOkHttpClient
import com.langchain.smith.models.runs.RunQueryV2Params
import com.langchain.smith.models.sessions.SessionListParams

val client: LangsmithClient = LangsmithOkHttpClient.fromEnv()

val project = client.sessions().list(
    SessionListParams.builder().name("default").limit(1L).build()
).items().first()
val runs = client.runs().queryV2(
    RunQueryV2Params.builder()
        .addProjectId(project.id())
        .minStartTime(OffsetDateTime.now().minusDays(1))
        .runType(RunQueryV2Params.RunType.LLM)
        .build()
).items()

StartTime is renamed to MinStartTime, and RunType now takes the new RunQueryV2ParamsRunType enum instead of RunTypeEnum.

Before
After

Before

package main

import (
	"context"
	"time"

	"github.com/langchain-ai/langsmith-go"
)

ctx := context.Background()
client := langsmith.NewClient()

sessions, err := client.Sessions.List(ctx, langsmith.SessionListParams{
	Name:  langsmith.F("default"),
	Limit: langsmith.F(int64(1)),
})
project := sessions.Items[0]

runs, err := client.Runs.Query(ctx, langsmith.RunQueryParams{
	Session:   langsmith.F([]string{project.ID}),
	StartTime: langsmith.F(time.Now().Add(-24 * time.Hour)),
	RunType:   langsmith.F(langsmith.RunTypeEnumLlm),
})

After

package main

import (
	"context"
	"time"

	"github.com/langchain-ai/langsmith-go"
)

ctx := context.Background()
client := langsmith.NewClient()

sessions, err := client.Sessions.List(ctx, langsmith.SessionListParams{
	Name:  langsmith.F("default"),
	Limit: langsmith.F(int64(1)),
})
project := sessions.Items[0]

runs, err := client.Runs.QueryV2(ctx, langsmith.RunQueryV2Params{
	ProjectIDs:   langsmith.F([]string{project.ID}),
	MinStartTime: langsmith.F(time.Now().Add(-24 * time.Hour)),
	RunType:      langsmith.F(langsmith.RunQueryV2ParamsRunTypeLlm),
})

start_time is renamed to min_start_time, and run_type values are now uppercase ("llm" → "LLM").

Before
After

PROJECT_ID=$(curl -s "https://api.smith.langchain.com/api/v1/sessions?name=default&limit=1" \
  -H "x-api-key: $LANGSMITH_API_KEY" | jq -r '.[0].id')

curl -X POST "https://api.smith.langchain.com/api/v1/runs/query" \
  -H "x-api-key: $LANGSMITH_API_KEY" \
  -H "Content-Type: application/json" \
  -d "$(jq -n --arg pid "$PROJECT_ID" '{"session": [$pid], "run_type": "llm", "start_time": "2025-01-01T00:00:00Z"}')"

PROJECT_ID=$(curl -s "https://api.smith.langchain.com/api/v1/sessions?name=default&limit=1" \
  -H "x-api-key: $LANGSMITH_API_KEY" | jq -r '.[0].id')

curl -X POST "https://api.smith.langchain.com/v2/runs/query" \
  -H "x-api-key: $LANGSMITH_API_KEY" \
  -H "Content-Type: application/json" \
  -d "$(jq -n --arg pid "$PROJECT_ID" '{"project_ids": [$pid], "run_type": "LLM", "min_start_time": "2025-01-01T00:00:00Z"}')"

Filter root runs only

Python
TypeScript
Java
Go
cURL

is_root is unchanged.

Before
After

Before

from langsmith import Client

client = Client()
runs = client.list_runs(project_name="default", is_root=True)

After

import asyncio

from langsmith import Client

async def main():
    client = Client()
    project = await client.aread_project(project_name="default")
    runs = client.runs.query(project_ids=[str(project.id)], is_root=True)

asyncio.run(main())

isRoot (camelCase) becomes is_root (snake_case, matching the v2 request body).

Before
After

Before

import { Client } from "langsmith";

const client = new Client();
const runs = client.listRuns({ projectName: "default", isRoot: true });

After

import { Client } from "langsmith";

const client = new Client();
const project = await client.readProject({ projectName: "default" });
const runs = client.runs.query({
  project_ids: [project.id],
  is_root: true,
});

.isRoot() is unchanged.

Before
After

Before

import com.langchain.smith.client.LangsmithClient
import com.langchain.smith.client.okhttp.LangsmithOkHttpClient
import com.langchain.smith.models.runs.RunQueryParams
import com.langchain.smith.models.sessions.SessionListParams

val client: LangsmithClient = LangsmithOkHttpClient.fromEnv()

val project = client.sessions().list(
    SessionListParams.builder().name("default").limit(1L).build()
).items().first()
val runs = client.runs().query(
    RunQueryParams.builder().addSession(project.id()).isRoot(true).build()
).items()

After

import com.langchain.smith.client.LangsmithClient
import com.langchain.smith.client.okhttp.LangsmithOkHttpClient
import com.langchain.smith.models.runs.RunQueryV2Params
import com.langchain.smith.models.sessions.SessionListParams

val client: LangsmithClient = LangsmithOkHttpClient.fromEnv()

val project = client.sessions().list(
    SessionListParams.builder().name("default").limit(1L).build()
).items().first()
val runs = client.runs().queryV2(
    RunQueryV2Params.builder().addProjectId(project.id()).isRoot(true).build()
).items()

IsRoot is unchanged.

Before
After

Before

package main

import (
	"context"

	"github.com/langchain-ai/langsmith-go"
)

ctx := context.Background()
client := langsmith.NewClient()

sessions, err := client.Sessions.List(ctx, langsmith.SessionListParams{
	Name:  langsmith.F("default"),
	Limit: langsmith.F(int64(1)),
})
project := sessions.Items[0]

runs, err := client.Runs.Query(ctx, langsmith.RunQueryParams{
	Session: langsmith.F([]string{project.ID}),
	IsRoot:  langsmith.F(true),
})

After

package main

import (
	"context"

	"github.com/langchain-ai/langsmith-go"
)

ctx := context.Background()
client := langsmith.NewClient()

sessions, err := client.Sessions.List(ctx, langsmith.SessionListParams{
	Name:  langsmith.F("default"),
	Limit: langsmith.F(int64(1)),
})
project := sessions.Items[0]

runs, err := client.Runs.QueryV2(ctx, langsmith.RunQueryV2Params{
	ProjectIDs: langsmith.F([]string{project.ID}),
	IsRoot:     langsmith.F(true),
})

is_root is unchanged.

Before
After

PROJECT_ID=$(curl -s "https://api.smith.langchain.com/api/v1/sessions?name=default&limit=1" \
  -H "x-api-key: $LANGSMITH_API_KEY" | jq -r '.[0].id')

curl -X POST "https://api.smith.langchain.com/api/v1/runs/query" \
  -H "x-api-key: $LANGSMITH_API_KEY" \
  -H "Content-Type: application/json" \
  -d "$(jq -n --arg pid "$PROJECT_ID" '{"session": [$pid], "is_root": true}')"

PROJECT_ID=$(curl -s "https://api.smith.langchain.com/api/v1/sessions?name=default&limit=1" \
  -H "x-api-key: $LANGSMITH_API_KEY" | jq -r '.[0].id')

curl -X POST "https://api.smith.langchain.com/v2/runs/query" \
  -H "x-api-key: $LANGSMITH_API_KEY" \
  -H "Content-Type: application/json" \
  -d "$(jq -n --arg pid "$PROJECT_ID" '{"project_ids": [$pid], "is_root": true}')"

Fetch runs by ID list

Python
TypeScript
Java
Go
cURL

id=[...] is renamed to ids=[...]. project_ids is now required even when filtering by run IDs—v1 allowed omitting the project context.

Before
After

Before

from langsmith import Client

client = Client()
runs = client.list_runs(id=["<run-id-1>", "<run-id-2>"])

After

import asyncio

from langsmith import Client


async def main():
    client = Client()
    project = await client.aread_project(project_name="default")
    runs = client.runs.query(
        project_ids=[str(project.id)],
        ids=["<run-id-1>", "<run-id-2>"],
    )


asyncio.run(main())

id: [...] is renamed to ids: [...]. project_ids is now required even when filtering by run IDs—v1 allowed omitting the project context.

Before
After

Before

import { Client } from "langsmith";

const client = new Client();
const runs = client.listRuns({ id: ["<run-id-1>", "<run-id-2>"] });

After

import { Client } from "langsmith";

const client = new Client();
const project = await client.readProject({ projectName: "default" });
const runs = client.runs.query({
  project_ids: [project.id],
  ids: ["<run-id-1>", "<run-id-2>"],
});

.addId(...) is unchanged—call it once per run ID. .addProjectId(...) is now required even when filtering by run IDs—v1 allowed omitting the project context.

Before
After

Before

import com.langchain.smith.client.LangsmithClient
import com.langchain.smith.client.okhttp.LangsmithOkHttpClient
import com.langchain.smith.models.runs.RunQueryParams
import com.langchain.smith.models.sessions.SessionListParams

val client: LangsmithClient = LangsmithOkHttpClient.fromEnv()

val project = client.sessions().list(
    SessionListParams.builder().name("default").limit(1L).build()
).items().first()
var runId1 = "<run-id-1>"
var runId2 = "<run-id-2>"
val runs = client.runs().query(
    RunQueryParams.builder()
        .addSession(project.id())
        .addId(runId1)
        .addId(runId2)
        .build()
).items()

After

import com.langchain.smith.client.LangsmithClient
import com.langchain.smith.client.okhttp.LangsmithOkHttpClient
import com.langchain.smith.models.runs.RunQueryV2Params
import com.langchain.smith.models.sessions.SessionListParams

val client: LangsmithClient = LangsmithOkHttpClient.fromEnv()

val project = client.sessions().list(
    SessionListParams.builder().name("default").limit(1L).build()
).items().first()
val runs = client.runs().queryV2(
    RunQueryV2Params.builder()
        .addProjectId(project.id())
        .addId("<run-id-1>")
        .addId("<run-id-2>")
        .build()
).items()

ID: [...] is renamed to IDs: [...]. ProjectIDs is now required even when filtering by run IDs—v1 allowed omitting the project context.

Before
After

Before

package main

import (
	"context"

	"github.com/langchain-ai/langsmith-go"
)

ctx := context.Background()
client := langsmith.NewClient()

sessions, err := client.Sessions.List(ctx, langsmith.SessionListParams{
	Name:  langsmith.F("default"),
	Limit: langsmith.F(int64(1)),
})
project := sessions.Items[0]

runID1 := "<run-id-1>"
runID2 := "<run-id-2>"
runs, err := client.Runs.Query(ctx, langsmith.RunQueryParams{
	Session: langsmith.F([]string{project.ID}),
	ID:      langsmith.F([]string{runID1, runID2}),
})

After

package main

import (
	"context"

	"github.com/langchain-ai/langsmith-go"
)

ctx := context.Background()
client := langsmith.NewClient()

sessions, err := client.Sessions.List(ctx, langsmith.SessionListParams{
	Name:  langsmith.F("default"),
	Limit: langsmith.F(int64(1)),
})
project := sessions.Items[0]

runID1 := "<run-id-1>"
runID2 := "<run-id-2>"
runs, err := client.Runs.QueryV2(ctx, langsmith.RunQueryV2Params{
	ProjectIDs: langsmith.F([]string{project.ID}),
	IDs:        langsmith.F([]string{runID1, runID2}),
})

id is renamed to ids. project_ids is now required in the request body even when filtering by run IDs—v1 allowed omitting the project context.

Before
After

RUN_ID_1="<run-id-1>"
RUN_ID_2="<run-id-2>"

curl -X POST "https://api.smith.langchain.com/api/v1/runs/query" \
  -H "x-api-key: $LANGSMITH_API_KEY" \
  -H "Content-Type: application/json" \
  -d "$(jq -n --arg r1 "$RUN_ID_1" --arg r2 "$RUN_ID_2" '{"id": [$r1, $r2]}')"

PROJECT_ID=$(curl -s "https://api.smith.langchain.com/api/v1/sessions?name=default&limit=1" \
  -H "x-api-key: $LANGSMITH_API_KEY" | jq -r '.[0].id')

RUN_ID_1="<run-id-1>"
RUN_ID_2="<run-id-2>"

curl -X POST "https://api.smith.langchain.com/v2/runs/query" \
  -H "x-api-key: $LANGSMITH_API_KEY" \
  -H "Content-Type: application/json" \
  -d "$(jq -n --arg pid "$PROJECT_ID" --arg r1 "$RUN_ID_1" --arg r2 "$RUN_ID_2" '{"project_ids": [$pid], "ids": [$r1, $r2]}')"

Iterate through runs

Python
TypeScript
Java
Go
cURL

list_runs auto-paginates transparently, fetching up to 100 runs per API call and stopping once limit results are returned. runs.query does not accept a total limit; iterate with async for and break once you have enough, or use the returned page’s has_next_page()/get_next_page() for manual page-by-page control.

Before
After

Before

from langsmith import Client

client = Client()
runs = client.list_runs(project_name="default", limit=150)

After

import asyncio

from langsmith import Client


async def main():
    client = Client()
    project = await client.aread_project(project_name="default")
    runs = []
    async for run in client.runs.query(
        project_ids=[str(project.id)],
    ):
        runs.append(run)
        if len(runs) >= 150:
            break


asyncio.run(main())

listRuns auto-paginates transparently. client.runs.query returns an async iterable of individual runs—use for await and break once you have enough.

Before
After

Before

import { Client } from "langsmith";

const client = new Client();
const runs: unknown[] = [];
for await (const run of client.listRuns({ projectName: "default" })) {
  runs.push(run);
  if (runs.length >= 150) break;
}

After

import { Client } from "langsmith";

const client = new Client();
const project = await client.readProject({ projectName: "default" });
const runs: unknown[] = [];
for await (const run of client.runs.query({
  project_ids: [project.id],
})) {
  runs.push(run);
  if (runs.length >= 150) break;
}

.autoPager() is used the same way on both query() and queryV2()—break out of the loop once you have enough runs.

Before
After

Before

import com.langchain.smith.client.LangsmithClient
import com.langchain.smith.client.okhttp.LangsmithOkHttpClient
import com.langchain.smith.models.runs.RunQueryParams
import com.langchain.smith.models.sessions.SessionListParams

val client: LangsmithClient = LangsmithOkHttpClient.fromEnv()

val project = client.sessions().list(
    SessionListParams.builder().name("default").limit(1L).build()
).items().first()
val runs = mutableListOf<Any>()
for (run in client.runs().query(
    RunQueryParams.builder().addSession(project.id()).build()
).autoPager()) {
    runs.add(run)
    if (runs.size >= 150) break
}

After

import com.langchain.smith.client.LangsmithClient
import com.langchain.smith.client.okhttp.LangsmithOkHttpClient
import com.langchain.smith.models.runs.RunQueryV2Params
import com.langchain.smith.models.sessions.SessionListParams

val client: LangsmithClient = LangsmithOkHttpClient.fromEnv()

val project = client.sessions().list(
    SessionListParams.builder().name("default").limit(1L).build()
).items().first()
val runs = mutableListOf<Any>()
for (run in client.runs().queryV2(
    RunQueryV2Params.builder().addProjectId(project.id()).build()
).autoPager()) {
    runs.add(run)
    if (runs.size >= 150) break
}

QueryAutoPaging is renamed to QueryV2AutoPaging; both use the same iter.Next()/iter.Current() pattern—break out of the loop once you have enough runs.

Before
After

Before

package main

import (
	"context"

	"github.com/langchain-ai/langsmith-go"
)

ctx := context.Background()
client := langsmith.NewClient()

sessions, err := client.Sessions.List(ctx, langsmith.SessionListParams{
	Name:  langsmith.F("default"),
	Limit: langsmith.F(int64(1)),
})
project := sessions.Items[0]

runs := []langsmith.RunSchema{}
iter := client.Runs.QueryAutoPaging(ctx, langsmith.RunQueryParams{
	Session: langsmith.F([]string{project.ID}),
})
for iter.Next() {
	runs = append(runs, iter.Current())
	if len(runs) >= 150 {
		break
	}
}

After

package main

import (
	"context"

	"github.com/langchain-ai/langsmith-go"
)

ctx := context.Background()
client := langsmith.NewClient()

sessions, err := client.Sessions.List(ctx, langsmith.SessionListParams{
	Name:  langsmith.F("default"),
	Limit: langsmith.F(int64(1)),
})
project := sessions.Items[0]

runs := []langsmith.Run{}
iter := client.Runs.QueryV2AutoPaging(ctx, langsmith.RunQueryV2Params{
	ProjectIDs: langsmith.F([]string{project.ID}),
})
for iter.Next() {
	runs = append(runs, iter.Current())
	if len(runs) >= 150 {
		break
	}
}

The v1 API returns all matching runs in one response with no cursor. The v2 API paginates—pass the cursor from a response’s next_cursor field to fetch the next page.

Before
After

PROJECT_ID=$(curl -s "https://api.smith.langchain.com/api/v1/sessions?name=default&limit=1" \
  -H "x-api-key: $LANGSMITH_API_KEY" | jq -r '.[0].id')

curl -X POST "https://api.smith.langchain.com/api/v1/runs/query" \
  -H "x-api-key: $LANGSMITH_API_KEY" \
  -H "Content-Type: application/json" \
  -d "$(jq -n --arg pid "$PROJECT_ID" '{"session": [$pid], "limit": 150}')"

PROJECT_ID=$(curl -s "https://api.smith.langchain.com/api/v1/sessions?name=default&limit=1" \
  -H "x-api-key: $LANGSMITH_API_KEY" | jq -r '.[0].id')

# Fetch pages, passing the cursor from each response's next_cursor field
# to fetch the next page, until 150 runs are collected or pages run out.
TOTAL=0
CURSOR=""
while :; do
  BODY=$(jq -n --arg pid "$PROJECT_ID" --arg cursor "$CURSOR" \
    'if $cursor == "" then {"project_ids": [$pid]} else {"project_ids": [$pid], "cursor": $cursor} end')
  RESPONSE=$(curl -s -X POST "https://api.smith.langchain.com/v2/runs/query" \
    -H "x-api-key: $LANGSMITH_API_KEY" \
    -H "Content-Type: application/json" \
    -d "$BODY")
  TOTAL=$((TOTAL + $(echo "$RESPONSE" | jq '.items | length')))
  CURSOR=$(echo "$RESPONSE" | jq -r '.next_cursor // empty')
  [ "$TOTAL" -lt 150 ] && [ -n "$CURSOR" ] || break
done

Filter runs with errors

Python
TypeScript
Java
Go
cURL

error=True/False is renamed to has_error=True/False.

Before
After

Before

from langsmith import Client

client = Client()
runs = client.list_runs(project_name="default", error=True)

After

import asyncio

from langsmith import Client

async def main():
    client = Client()
    project = await client.aread_project(project_name="default")
    runs = client.runs.query(project_ids=[str(project.id)], has_error=True)

asyncio.run(main())

error: true/false is renamed to has_error: true/false.

Before
After

Before

import { Client } from "langsmith";

const client = new Client();
const runs = client.listRuns({ projectName: "default", error: true });

After

import { Client } from "langsmith";

const client = new Client();
const project = await client.readProject({ projectName: "default" });
const runs = client.runs.query({
  project_ids: [project.id],
  has_error: true,
});

.error(true/false) is renamed to .hasError(true/false).

Before
After

Before

import com.langchain.smith.client.LangsmithClient
import com.langchain.smith.client.okhttp.LangsmithOkHttpClient
import com.langchain.smith.models.runs.RunQueryParams
import com.langchain.smith.models.sessions.SessionListParams

val client: LangsmithClient = LangsmithOkHttpClient.fromEnv()

val project = client.sessions().list(
    SessionListParams.builder().name("default").limit(1L).build()
).items().first()
val runs = client.runs().query(
    RunQueryParams.builder().addSession(project.id()).error(true).build()
).items()

After

import com.langchain.smith.client.LangsmithClient
import com.langchain.smith.client.okhttp.LangsmithOkHttpClient
import com.langchain.smith.models.runs.RunQueryV2Params
import com.langchain.smith.models.sessions.SessionListParams

val client: LangsmithClient = LangsmithOkHttpClient.fromEnv()

val project = client.sessions().list(
    SessionListParams.builder().name("default").limit(1L).build()
).items().first()
val runs = client.runs().queryV2(
    RunQueryV2Params.builder().addProjectId(project.id()).hasError(true).build()
).items()

Error is renamed to HasError.

Before
After

Before

package main

import (
	"context"

	"github.com/langchain-ai/langsmith-go"
)

ctx := context.Background()
client := langsmith.NewClient()

sessions, err := client.Sessions.List(ctx, langsmith.SessionListParams{
	Name:  langsmith.F("default"),
	Limit: langsmith.F(int64(1)),
})
project := sessions.Items[0]

runs, err := client.Runs.Query(ctx, langsmith.RunQueryParams{
	Session: langsmith.F([]string{project.ID}),
	Error:   langsmith.F(true),
})

After

package main

import (
	"context"

	"github.com/langchain-ai/langsmith-go"
)

ctx := context.Background()
client := langsmith.NewClient()

sessions, err := client.Sessions.List(ctx, langsmith.SessionListParams{
	Name:  langsmith.F("default"),
	Limit: langsmith.F(int64(1)),
})
project := sessions.Items[0]

runs, err := client.Runs.QueryV2(ctx, langsmith.RunQueryV2Params{
	ProjectIDs: langsmith.F([]string{project.ID}),
	HasError:   langsmith.F(true),
})

error is renamed to has_error.

Before
After

PROJECT_ID=$(curl -s "https://api.smith.langchain.com/api/v1/sessions?name=default&limit=1" \
  -H "x-api-key: $LANGSMITH_API_KEY" | jq -r '.[0].id')

curl -X POST "https://api.smith.langchain.com/api/v1/runs/query" \
  -H "x-api-key: $LANGSMITH_API_KEY" \
  -H "Content-Type: application/json" \
  -d "$(jq -n --arg pid "$PROJECT_ID" '{"session": [$pid], "error": true}')"

PROJECT_ID=$(curl -s "https://api.smith.langchain.com/api/v1/sessions?name=default&limit=1" \
  -H "x-api-key: $LANGSMITH_API_KEY" | jq -r '.[0].id')

curl -X POST "https://api.smith.langchain.com/v2/runs/query" \
  -H "x-api-key: $LANGSMITH_API_KEY" \
  -H "Content-Type: application/json" \
  -d "$(jq -n --arg pid "$PROJECT_ID" '{"project_ids": [$pid], "has_error": true}')"

Filter by metadata

Python
TypeScript
Java
Go
cURL

The filter string syntax is unchanged: eq(metadata_key, ...) checks for key presence, combined with eq(metadata_value, ...) to match a specific value.

Before
After

Before

from langsmith import Client

client = Client()
filter_str = 'and(eq(metadata_key, "user_id"), eq(metadata_value, "u_123"))'
runs = client.list_runs(project_name="default", filter=filter_str)

After

import asyncio

from langsmith import Client


async def main():
    client = Client()
    filter_str = 'and(eq(metadata_key, "user_id"), eq(metadata_value, "u_123"))'
    project = await client.aread_project(project_name="default")
    runs = client.runs.query(project_ids=[str(project.id)], filter=filter_str)


asyncio.run(main())

The filter string syntax is unchanged: eq(metadata_key, ...) checks for key presence, combined with eq(metadata_value, ...) to match a specific value.

Before
After

Before

import { Client } from "langsmith";

const client = new Client();
const filterStr = 'and(eq(metadata_key, "user_id"), eq(metadata_value, "u_123"))';
const runs = client.listRuns({ projectName: "default", filter: filterStr });

After

import { Client } from "langsmith";

const client = new Client();
const filterStr = 'and(eq(metadata_key, "user_id"), eq(metadata_value, "u_123"))';
const project = await client.readProject({ projectName: "default" });
const runs = client.runs.query({
  project_ids: [project.id],
  filter: filterStr,
});

The .filter(...) string syntax is unchanged: eq(metadata_key, ...) checks for key presence, combined with eq(metadata_value, ...) to match a specific value.

Before
After

Before

import com.langchain.smith.client.LangsmithClient
import com.langchain.smith.client.okhttp.LangsmithOkHttpClient
import com.langchain.smith.models.runs.RunQueryParams
import com.langchain.smith.models.sessions.SessionListParams

val client: LangsmithClient = LangsmithOkHttpClient.fromEnv()

val project = client.sessions().list(
    SessionListParams.builder().name("default").limit(1L).build()
).items().first()
val filterStr = "and(eq(metadata_key, \"user_id\"), eq(metadata_value, \"u_123\"))"
val runs = client.runs().query(
    RunQueryParams.builder().addSession(project.id()).filter(filterStr).build()
).items()

After

import com.langchain.smith.client.LangsmithClient
import com.langchain.smith.client.okhttp.LangsmithOkHttpClient
import com.langchain.smith.models.runs.RunQueryV2Params
import com.langchain.smith.models.sessions.SessionListParams

val client: LangsmithClient = LangsmithOkHttpClient.fromEnv()

val project = client.sessions().list(
    SessionListParams.builder().name("default").limit(1L).build()
).items().first()
val filterStr = "and(eq(metadata_key, \"user_id\"), eq(metadata_value, \"u_123\"))"
val runs = client.runs().queryV2(
    RunQueryV2Params.builder().addProjectId(project.id()).filter(filterStr).build()
).items()

The Filter string syntax is unchanged: eq(metadata_key, ...) checks for key presence, combined with eq(metadata_value, ...) to match a specific value.

Before
After

Before

package main

import (
	"context"

	"github.com/langchain-ai/langsmith-go"
)

ctx := context.Background()
client := langsmith.NewClient()

sessions, err := client.Sessions.List(ctx, langsmith.SessionListParams{
	Name:  langsmith.F("default"),
	Limit: langsmith.F(int64(1)),
})
project := sessions.Items[0]

filterStr := `and(eq(metadata_key, "user_id"), eq(metadata_value, "u_123"))`
runs, err := client.Runs.Query(ctx, langsmith.RunQueryParams{
	Session: langsmith.F([]string{project.ID}),
	Filter:  langsmith.F(filterStr),
})

After

package main

import (
	"context"

	"github.com/langchain-ai/langsmith-go"
)

ctx := context.Background()
client := langsmith.NewClient()

sessions, err := client.Sessions.List(ctx, langsmith.SessionListParams{
	Name:  langsmith.F("default"),
	Limit: langsmith.F(int64(1)),
})
project := sessions.Items[0]

filterStr := `and(eq(metadata_key, "user_id"), eq(metadata_value, "u_123"))`
runs, err := client.Runs.QueryV2(ctx, langsmith.RunQueryV2Params{
	ProjectIDs: langsmith.F([]string{project.ID}),
	Filter:     langsmith.F(filterStr),
})

The filter string syntax is unchanged: eq(metadata_key, ...) checks for key presence, combined with eq(metadata_value, ...) to match a specific value.

Before
After

PROJECT_ID=$(curl -s "https://api.smith.langchain.com/api/v1/sessions?name=default&limit=1" \
  -H "x-api-key: $LANGSMITH_API_KEY" | jq -r '.[0].id')

FILTER='and(eq(metadata_key, "user_id"), eq(metadata_value, "u_123"))'

curl -X POST "https://api.smith.langchain.com/api/v1/runs/query" \
  -H "x-api-key: $LANGSMITH_API_KEY" \
  -H "Content-Type: application/json" \
  -d "$(jq -n --arg pid "$PROJECT_ID" --arg f "$FILTER" '{"session": [$pid], "filter": $f}')"

PROJECT_ID=$(curl -s "https://api.smith.langchain.com/api/v1/sessions?name=default&limit=1" \
  -H "x-api-key: $LANGSMITH_API_KEY" | jq -r '.[0].id')

FILTER='and(eq(metadata_key, "user_id"), eq(metadata_value, "u_123"))'

curl -X POST "https://api.smith.langchain.com/v2/runs/query" \
  -H "x-api-key: $LANGSMITH_API_KEY" \
  -H "Content-Type: application/json" \
  -d "$(jq -n --arg pid "$PROJECT_ID" --arg f "$FILTER" '{"project_ids": [$pid], "filter": $f}')"