Connectors · AI
LangSmith MCP server for AI agents.
actionlake is an MCP gateway: one remote MCP server that connects Claude and other MCP clients to LangSmith and the rest of your systems. It gives your agent 530 LangSmith actions (244 reads, 184 writes and 102 that wait for a confirmation) and holds the LangSmith credential itself, so the agent never does. It paces LangSmith's limits and records every call.
100,000 free calls a month. No card, no email, no password: press Start a free sandbox on the next screen and keep the key it shows you.
claude mcp add --transport http actionlake https://connect.actionlake.com/mcpdo { action: "langsmith.datasets.list", intent: "check which LangSmith account is connected"}# Read Datasets · read · 1 upstream call- 530actionsin one signed file
- 244readlook, never change
- 184writecreate and update
- 102wait for a yesdestructive, confirmed first
Set up
Connect LangSmith in three steps.
- 01
Add actionlake to Claude.
Run the command once in Claude Code; its consent page can create a free sandbox: 100,000 calls a month, no card. In the Claude app, add a custom connector with the URL below and paste your key on the consent page. Creating a new sandbox from the Claude app is not yet tested by us.
https://connect.actionlake.com/mcp - 02
Connect LangSmith.
API key. No consent screen: your agent can connect it for you, but the key then passes through your chat. To keep it out of the model's context, paste it in the console instead. actionlake stores what you paste write-only, sealed under your tenant's key.
api_keyLangSmith API key: in LangSmith open Settings > API Keys and create a Personal Access Token (lsv2_pt_...) or a…hostWhere your LangSmith lives: your hostorganization_idYour LangSmith organization idworkspace_idYour LangSmith workspace id
account { op: "connections.requirements", service: "langsmith" } # free: exactly what to paste, and what is found for you - 03
Make the first call. Check before a write.
Ask in plain words; Claude picks the action. Before anything changes,
checkvalidates the call and prices it, for free.do { action: "langsmith.datasets.list" }# read datasets · read · 1 upstream callcheck { action: "langsmith.datasets.create", input: { … } }# free: inputs, permissions, cost and confirmations, nothing sent
LangSmith at a glance
- Sign-in
- API key. No consent screen: your agent can connect it for you, but the key then passes through your chat. To keep it out of the model's context, paste it in the console instead.
- You provide
api_key- Setup fields
hostorganization_idworkspace_id- Limits we pace to
- 600 calls a minute, per connection
- API covered
- LangSmith API (spec 0.1.0, OpenAPI 3.1.0)
api.smith.langchain.com - Built from
- LangSmith's documentation, read 23 October 2026api.smith.langchain.comdocs.smith.langchain.com
- Service file
- Version 1.0.0, signed (Ed25519)
- Cached reads
- 189 of 244 reads, for up to 5 minutes; a write clears what it affects
- Shared entities
- 4, so ask can line LangSmith up with your other systems
- Data
- Processed and stored in Sydney, Australia. No US region yet
Capabilities
What an AI agent can do in LangSmith.
530 actions in 63 areas. Every one carries its effect, so a key can allow the reads and hold the rest.
- 244readlook, never change
- 184writecreate and update
- 102destructivewait for a confirmation
Orgs
5219 read · 20 write · 13 destructive
Get Current Active Org Members · On Payment Method Created · Create Customers And Get Stripe Setup Intent · Create Stripe Checkout Sessions Endpoint
Sandboxes
3914 read · 18 write · 7 destructive
Execute a sandbox command · Glob a sandbox filesystem · Grep a sandbox filesystem · Create a sandbox
Workspaces
3918 read · 11 write · 10 destructive
List Workspaces · Get Current Active Workspace Members · Create Workspace · Patch Workspace
Annotation queues
3012 read · 12 write · 6 destructive
Create Annotation Queue · Export Annotation Queue Archived Runs · Get Annotation Queues · Populate Annotation Queue
Tracer sessions
2611 read · 10 write · 5 destructive
Create Tracer Session · Get Tracing Project Prebuilt Dashboard · Read Tracer Sessions · [Beta] Create Insights Job
Datasets
2410 read · 10 write · 4 destructive
Read Datasets · Create Dataset · Read Dataset · Update Dataset
Charts
2310 read · 9 write · 4 destructive
Create Chart · Read Chart Preview · Read Charts · Read Single Chart
Run
2314 read · 5 write · 4 destructive
Generate Query For Runs · Group Runs · Stats Group Runs · Query Runs
55 more areas · 274 actions
- Public 17
- Feedback 14
- Examples 13
- Bulk exports 12
- Runs 12
- Threads 12
- MCP vendors 9
- Optimization jobs 9
- Repos 9
- Access policies 8
- Oauth 8
- Tools 8
- Evaluators 7
- Issues agent 7
- API key 6
- Comments 6
- Gateway policies 6
- Prompt webhooks 6
- Agents 5
- Alert rules 5
- Data planes 5
- Features 5
- Playground settings 5
- Scim tokens 5
- Tags 5
- Feedback configs 4
- Fleet secrets 4
- Hub environments 4
- Issues 4
- Model price map 4
- TTL settings 4
- Usage limits 4
- Commits 3
- Directories 3
- Fleet users 3
- MCP 3
- Ownerships 3
- Service accounts 3
- Audit logs 2
- Info 2
- Integrations 2
- Productfeedback 2
- Sessions 2
- Settings 2
- Usage 2
- Ace 1
- Backfills 1
- Experiments 1
- Fleet orgs 1
- Fleet tenants 1
- Fleet threads 1
- Likes 1
- Me 1
- Organizations 1
- Prompts 1
Top actions
The LangSmith API, shaped for agents.
The ids your agent types, what each does, and the one name it shares with other systems. 14 of LangSmith's 14 action names are shared with at least one other connector, so an agent learns them once.
| Action | What it does | Effect | Same name in |
|---|---|---|---|
langsmith.datasets.listRead Datasets | Read Datasets. | read | analytics.dataset.list28 connectors |
langsmith.workspaces.listList Workspaces | List Workspaces. | read | work.workspace.list50 connectors |
langsmith.workspaces_current_members_active.listGet Current Active Workspace Members | Get Current Active Workspace Members. | read | work.workspace_member.list26 connectors |
langsmith.datasets.createCreate Dataset | Create Dataset. | write | analytics.dataset.create21 connectors |
langsmith.workspaces.createCreate Workspace | Create Workspace. | write | work.workspace.create36 connectors |
langsmith.datasets.deleteDelete Datasets | Delete Datasets. | destructive | analytics.dataset.delete23 connectors |
langsmith.audit_logs.listGet Audit Logs | Get Audit Logs. | read | identity.audit_event.list51 connectors |
langsmith.service_accounts.listGet Service Accounts | Get Service Accounts. | read | identity.service_account.list35 connectors |
langsmith.service_accounts.createCreate Service Account | Create Service Account. | write | identity.service_account.create32 connectors |
langsmith.orgs_current_members_active.listGet Current Active Org Members | Get Current Active Org Members. | read | this connector |
langsmith.repos.forkFork Repo | Fork Repo. | write | this connector |
langsmith.repos.listList Repos | List Repos. | read | this connector |
Try it
Prompts to paste into Claude.
Each one names the LangSmith actions it will call, so you know what it reads and what it changes before you send it.
- Readread
Who has access in LangSmith? List every user and their role.
calls
langsmith.orgs_current_members_active.list - Writewrite
Create Dataset in LangSmith. Show me exactly what you will send before you save it.
calls
langsmith.datasets.create
Governance for LangSmith
Destructive actions wait for a yes.
102 LangSmith actions are destructive. The first 10:
- Delete Datasets
langsmith.datasets.delete - Delete Workspace
langsmith.workspaces.delete - Delete Service Account
langsmith.service_accounts.delete - Add Members To Current Org Batch
langsmith.orgs_current_members.batch - Add Member To Current Org
langsmith.orgs_current_members.create - Add Basic Auth Members To Current Org
langsmith.orgs_current_members_basic.batch - Add Members To Current Workspace Batch
langsmith.workspaces_current_members.batch - Add Member To Current Workspace
langsmith.workspaces_current_members.create - Attach access policies to a role
langsmith.platform_orgs_current_roles_access_policies.attach - Attach access policies to a role
langsmith.platform_orgs_current_access_policies.attach_to_role
A destructive action runs only with confirm: true. Under the human policy the agent cannot confirm for itself: the run stops until a named person approves, in the console or from a signed link in an email. The cap on a key is refused before the call is sent, never after.
Delete Datasets?
intent: the user asked me to delete Datasets
account { op: "keys.create", name: "langsmith-agent", allowed_actions: ["langsmith.*"], cap_calls: 2000, confirm_policy: "human_for_writes", approval_rules: [ { match: "langsmith.datasets.delete", approver: "[email protected]" }, { match: "langsmith.workspaces.delete", approver: "[email protected]" }, { match: "langsmith.service_accounts.delete", approver: "[email protected]" } ]}Cost
What LangSmith costs on actionlake.
Every LangSmith action is one upstream call, the only thing actionlake bills. Searching, check, cost, account and any call LangSmith refused with 401, 403, 429 or a 5xx are free. Paid plans start at US$49 a month for 250,000 calls, with overage from US$0.30 down to US$0.18 per 1,000.
- 1upstream call per actionall 530 LangSmith actions
- 530actions pageeach page of a long list is one call
- 189reads can be cacheda cache hit costs nothing
- 100,000calls a month, freepaid plans from US$49 a month for 250,000
Action index
Every LangSmith action.
530 actions by area: the id your agent calls, what it does, and its effect.
Orgs52
langsmith.orgs_current.payment_methodOn Payment Method Createdwritelangsmith.orgs_current.setupCreate Customers And Get Stripe Setup Intentwritelangsmith.orgs_current.stripe_checkout_sessionCreate Stripe Checkout Sessions Endpointwritelangsmith.orgs_current_members_active.listGet Current Active Org Membersreadlangsmith.orgs_current.getGet Organization Inforeadlangsmith.orgs_current.planChange Payment Plandestructive- and 46 more in this area
Sandboxes39
langsmith.sandboxes.executeExecute a sandbox commandwritelangsmith.sandboxes.globGlob a sandbox filesystemreadlangsmith.sandboxes.grepGrep a sandbox filesystemreadlangsmith.sandboxes_boxes.createCreate a sandboxwritelangsmith.sandboxes_boxes.batch_deleteBatch delete sandboxesdestructivelangsmith.sandboxes_boxes.deleteDelete a sandboxdestructive- and 33 more in this area
Workspaces39
langsmith.workspaces.createCreate Workspacewritelangsmith.workspaces.listList Workspacesreadlangsmith.workspaces.updatePatch Workspacewritelangsmith.workspaces_current_members_active.listGet Current Active Workspace Membersreadlangsmith.workspaces.deleteDelete Workspacedestructivelangsmith.workspaces.getGet Workspaceread- and 33 more in this area
Annotation queues30
langsmith.annotation_queues.createCreate Annotation Queuewritelangsmith.annotation_queues.exportExport Annotation Queue Archived Runswritelangsmith.annotation_queues.listGet Annotation Queuesreadlangsmith.annotation_queues.populatePopulate Annotation Queuewritelangsmith.annotation_queues.deleteDelete Annotation Queuesdestructivelangsmith.annotation_queues.delete_annotation_queueDelete Annotation Queuedestructive- and 24 more in this area
Tracer sessions26
langsmith.sessions.createCreate Tracer Sessionwritelangsmith.sessions.dashboardGet Tracing Project Prebuilt Dashboardreadlangsmith.sessions.listRead Tracer Sessionsreadlangsmith.sessions_insights.create[Beta] Create Insights Jobwritelangsmith.sessions.deleteDelete Tracer Sessiondestructivelangsmith.sessions.delete_tracer_sessionsDelete Tracer Sessionsdestructive- and 20 more in this area
Datasets24
langsmith.datasets.createCreate Datasetwritelangsmith.datasets.getRead Datasetreadlangsmith.datasets.listRead Datasetsreadlangsmith.datasets.updateUpdate Datasetwritelangsmith.datasets.cloneClone Datasetwritelangsmith.datasets.comparativeCreate Comparative Experimentwrite- and 18 more in this area
Charts23
langsmith.charts.createCreate Chartwritelangsmith.charts.previewRead Chart Previewreadlangsmith.charts.queryRead Chartsreadlangsmith.charts.query_oneRead Single Chartreadlangsmith.charts.deleteDelete Chartdestructivelangsmith.charts.updateUpdate Chartwrite- and 17 more in this area
Run23
langsmith.runs.generate_queryGenerate Query For Runsreadlangsmith.runs.groupGroup Runsreadlangsmith.runs.group_statsStats Group Runsreadlangsmith.runs.queryQuery Runsreadlangsmith.runs.deleteDelete Runsdestructivelangsmith.runs.delete_tracesDelete Runs Abacdestructive- and 17 more in this area
Public17
langsmith.public.query_runsQuery Shared Runsreadlangsmith.public_datasets_comparative.listRead Shared Comparative Experimentsreadlangsmith.public_datasets_feedback.listRead Shared Dataset Feedbackreadlangsmith.public_datasets_runs.generate_queryGenerate Query For Shared Dataset Runsreadlangsmith.public.get_runGet Shared Run By Idreadlangsmith.public.get_shared_runGet Shared Runread- and 11 more in this area
Feedback14
langsmith.feedback.createCreate Feedbackwritelangsmith.feedback.listRead Feedbacksreadlangsmith.feedback_formulas.createCreate Feedback Formula Epwritelangsmith.feedback_formulas.listList Feedback Formula Epreadlangsmith.feedback.deleteDelete Feedbackdestructivelangsmith.feedback.getRead Feedbackread- and 8 more in this area
Examples13
langsmith.examples.bulkCreate Exampleswritelangsmith.examples.createCreate Examplewritelangsmith.examples.listRead Examplesreadlangsmith.examples.validateValidate Examplereadlangsmith.examples.deleteDelete Exampledestructivelangsmith.examples.delete_examplesDelete Examplesdestructive- and 7 more in this area
Bulk exports12
langsmith.bulk_exports.createCreate Bulk Exportwritelangsmith.bulk_exports.listGet Bulk Exportsreadlangsmith.bulk_exports_destinations.createCreate Bulk Export Destinationwritelangsmith.bulk_exports_destinations.listGet Bulk Export Destinationsreadlangsmith.bulk_exports.getGet Bulk Exportreadlangsmith.bulk_exports.updateCancel Bulk Exportwrite- and 6 more in this area
Runs12
langsmith.public.query_runs_v2Query public shared trace runsreadlangsmith.runs.createCreate a Runwritelangsmith.runs.ingest_batchIngest Runs (Batch JSON)writelangsmith.runs.query_v2Query runsreadlangsmith.public.get_run_v2Get a public shared trace runreadlangsmith.runs.get_a_single_runGet a single runread- and 6 more in this area
Threads12
langsmith.public_threads_traces.listList traces in a public shared threadreadlangsmith.threads.queryQuery Threadsreadlangsmith.threads.statsQuery Thread Statsreadlangsmith.threads_share.createShare a threadwritelangsmith.public_threads.getGet a public shared thread's manifestreadlangsmith.public_threads_runs.getGet one run in a public shared threadread- and 6 more in this area
MCP vendors9
langsmith.platform_mcp_vendors.getList MCP vendorsreadlangsmith.platform_mcp_vendors_mcp_servers.listList MCP servers for a vendorreadlangsmith.platform_mcp_vendors_settings.createCreate vendor settingswritelangsmith.platform_mcp_vendors_tools.listList tools for a vendorreadlangsmith.platform_mcp_vendors.get_mcp_vendorGet MCP vendorreadlangsmith.platform_mcp_vendors_account.getGet vendor accountread- and 3 more in this area
Optimization jobs9
langsmith.repos_optimization_jobs.createCreate Jobwritelangsmith.repos_optimization_jobs.listList Jobsreadlangsmith.repos_optimization_jobs_logs.createCreate Logwritelangsmith.repos_optimization_jobs_logs.listList Job Logsreadlangsmith.repos_optimization_jobs.deleteDelete Jobdestructivelangsmith.repos_optimization_jobs.getGet Jobread- and 3 more in this area
Repos9
langsmith.repos.createCreate Repowritelangsmith.repos.forkFork Repowritelangsmith.repos.listList Reposreadlangsmith.repos.optimize_jobOptimize Prompt Jobwritelangsmith.repos.deleteDelete Reposdestructivelangsmith.repos.delete_repoDelete Repodestructive- and 3 more in this area
Access policies8
langsmith.platform_orgs_current_access_policies.attach_to_roleAttach access policies to a roledestructivelangsmith.platform_orgs_current_access_policies.createCreate an access policywritelangsmith.platform_orgs_current_access_policies.getList access policiesreadlangsmith.platform_orgs_current_roles_access_policies.attachAttach access policies to a roledestructivelangsmith.platform_orgs_current_access_policies.deleteDelete an access policydestructivelangsmith.platform_orgs_current_access_policies.get_an_access_policyGet an access policyread- and 2 more in this area
Oauth8
langsmith.platform_oauth_authorized_apps.listList authorized applicationsreadlangsmith.platform_oauth_clients.createCreate an OAuth clientwritelangsmith.platform_oauth_clients.getList OAuth clientsreadlangsmith.platform_oauth_clients.get_an_oauth_clientGet an OAuth clientreadlangsmith.platform_oauth_authorized_apps.deleteRevoke an authorized applicationdestructivelangsmith.platform_oauth_clients.deleteDelete an OAuth clientdestructive- and 2 more in this area
Tools8
langsmith.platform_tools.createCreate a toolwritelangsmith.platform_tools.getGet a tool by handlereadlangsmith.platform_tools.listList toolsreadlangsmith.platform_tools.updateUpdate a tool by handlewritelangsmith.platform_tools.deleteDelete a tool by handledestructivelangsmith.platform_tools_id.deleteDelete a tool by IDdestructive- and 2 more in this area
Evaluators7
langsmith.platform_evaluators.createCreate evaluatorwritelangsmith.platform_evaluators.getGet evaluatorreadlangsmith.platform_evaluators.listList evaluatorsreadlangsmith.platform_evaluators.updateUpdate evaluatorwritelangsmith.platform_evaluators.deleteBulk delete evaluatorsdestructivelangsmith.platform_evaluators.delete_evaluatorDelete evaluatordestructive- and 1 more in this area
Issues agent7
langsmith.platform_issues_agent.list[Beta] List issues agent configsreadlangsmith.platform_sessions_issues_agent.create[Beta] Create the issues agent for a sessionwritelangsmith.platform_sessions_issues_agent.get[Beta] Get the issues agent config for a sessionreadlangsmith.platform_sessions_issues_agent.update[Beta] Update the issues agent config for a sessionwritelangsmith.platform_sessions_issues_agent.delete[Beta] Delete the issues agent for a sessiondestructivelangsmith.platform_sessions_issues_agent_overview.update[Beta] Save the agent overview for a sessionwrite- and 1 more in this area
API key6
langsmith.api_key.createGenerate Api Keywritelangsmith.api_key.listGet Api Keysreadlangsmith.api_key_current.createGenerate Personal Access Tokenwritelangsmith.api_key_current.listGet Personal Access Tokensreadlangsmith.api_key.deleteDelete Api Keydestructivelangsmith.api_key_current.deleteDelete Personal Access Tokendestructive
Comments6
langsmith.comments.createCreate Commentwritelangsmith.comments.create_sub_commentCreate Sub Commentwritelangsmith.comments.get_sub_commentsGet Sub Commentsreadlangsmith.comments.likeLike Commentwritelangsmith.comments.listGet Commentsreadlangsmith.comments_like.deleteUnlike Commentdestructive
Gateway policies6
langsmith.platform_gateway_policies.createCreate a gateway policywritelangsmith.platform_gateway_policies.getGet a gateway policyreadlangsmith.platform_gateway_policies.listList gateway policiesreadlangsmith.platform_gateway_policies.searchSearch gateway policies by subject value setreadlangsmith.platform_gateway_policies.deleteDelete a gateway policydestructivelangsmith.platform_gateway_policies.updateUpdate a gateway policywrite
Prompt webhooks6
langsmith.prompt_webhooks.createCreate Prompt Webhookwritelangsmith.prompt_webhooks.getGet Prompt Webhookreadlangsmith.prompt_webhooks.listList Prompt Webhooksreadlangsmith.prompt_webhooks.testTest Prompt Webhookreadlangsmith.prompt_webhooks.deleteDelete Prompt Webhookdestructivelangsmith.prompt_webhooks.updateUpdate Prompt Webhookwrite
Agents5
langsmith.agents.createCreate an Agentwritelangsmith.agents.getGet an Agentreadlangsmith.agents.listList Agentsreadlangsmith.agents.updateUpdate an Agentwritelangsmith.agents.deleteDelete an Agentdestructive
Alert rules5
langsmith.platform_alerts.createCreate an alert rulewritelangsmith.platform_alerts.getGet an alert rulereadlangsmith.platform_alerts.testTest an alert action to determine if configuration is validreadlangsmith.platform_alerts.updateUpdate an alert rulewritelangsmith.platform_alerts.deleteDelete an alert ruledestructive
Data planes5
langsmith.orgs_current_data_planes.createCreate a new data planewritelangsmith.orgs_current_data_planes.getList data planes for the current organizationreadlangsmith.orgs_current_data_planes.get_a_data_planeGet a data planereadlangsmith.orgs_current_data_planes.updateUpdate data plane settingswritelangsmith.orgs_current_data_planes.deleteDelete a data planedestructive
Features5
langsmith.platform_features.listList feature configurationsreadlangsmith.platform_features_default_model.deleteDelete default model for a featuredestructivelangsmith.platform_features_default_model.updateSet default model for a featurewritelangsmith.platform_features_disabled_models.updateDisable a model for a featurewritelangsmith.platform_features_disabled_models.deleteRe-enable a disabled model for a featuredestructive
Playground settings5
langsmith.playground_settings.createCreate Playground Settingswritelangsmith.playground_settings.getGet Playground Settingsreadlangsmith.playground_settings.listList Playground Settingsreadlangsmith.playground_settings.updateUpdate Playground Settingswritelangsmith.playground_settings.deleteDelete Playground Settingsdestructive
Scim tokens5
langsmith.platform_orgs_current_scim_tokens.createCreate a SCIM tokenwritelangsmith.platform_orgs_current_scim_tokens.getGet a SCIM tokenreadlangsmith.platform_orgs_current_scim_tokens.listList SCIM tokensreadlangsmith.platform_orgs_current_scim_tokens.updateUpdate a SCIM tokenwritelangsmith.platform_orgs_current_scim_tokens.deleteDelete a SCIM tokendestructive
Tags5
langsmith.repos_tags.createCreate Tagwritelangsmith.repos_tags.getGet Tagreadlangsmith.repos_tags.get_tagsGet Tagsreadlangsmith.repos_tags.updateUpdate Tagwritelangsmith.repos_tags.deleteDelete Tagdestructive
Feedback configs4
langsmith.feedback_configs.createCreate Feedback Config Endpointwritelangsmith.feedback_configs.deleteDelete Feedback Config Endpointdestructivelangsmith.feedback_configs.listList Feedback Configs Endpointreadlangsmith.feedback_configs.updateUpdate Feedback Config Endpointwrite
Fleet secrets4
langsmith.fleet_secrets.createBulk set or delete workspace secretswritelangsmith.fleet_secrets.deleteDelete a workspace secretdestructivelangsmith.fleet_secrets.listList workspace secret namesreadlangsmith.fleet_secrets.updateSet a workspace secretwrite
Hub environments4
langsmith.hub_environments.createCreate hub environments modelwritelangsmith.hub_environments.deleteDelete hub environments modeldestructivelangsmith.hub_environments.getList hub environmentsreadlangsmith.hub_environments.updateUpdate hub environments modelwrite
Issues4
langsmith.platform_issues.get[Beta] Get issuereadlangsmith.platform_issues.list[Beta] List issuesreadlangsmith.platform_issues.views[Beta] Mark issue viewedwritelangsmith.platform_sessions_issues_views.get[Beta] List viewed issues for a sessionread
Model price map4
langsmith.model_price_map.createCreate New Model Pricewritelangsmith.model_price_map.deleteDelete Model Pricedestructivelangsmith.model_price_map.listRead Model Price Mapreadlangsmith.model_price_map.updateUpdate Model Pricewrite
TTL settings4
langsmith.ttl_settings.listList Ttl Settingsreadlangsmith.ttl_settings.updateUpsert Ttl Settingswritelangsmith.workspaces_current_ttl_settings.getGet workspace TTL settingsreadlangsmith.workspaces_current_ttl_settings.updateUpdate workspace TTL settingswrite
Usage limits4
langsmith.usage_limits.deleteDelete Usage Limitdestructivelangsmith.usage_limits.listList Usage Limitsreadlangsmith.usage_limits.updateUpsert Usage Limitwritelangsmith.usage_limits_org.listList Org Usage Limitsread
Commits3
langsmith.commits.createCreate a commitwritelangsmith.commits.getGet a commitreadlangsmith.commits.listList commitsread
Directories3
langsmith.platform_hub_repos_directories.deleteDelete directory repositorydestructivelangsmith.platform_hub_repos_directories.getGet directory contentsreadlangsmith.platform_hub_repos_directories_commits.createCreate directory commitwrite
Fleet users3
langsmith.fleet_tenants_users.getGet Fleet user in tenantreadlangsmith.fleet_users.listList Fleet usersreadlangsmith.fleet_users_current.getGet current Fleet userread
MCP3
langsmith.mcp_proxy.createProxywritelangsmith.mcp_tools.deleteInvalidate Tools Cachedestructivelangsmith.mcp_tools.getGet Toolsread
Ownerships3
langsmith.repos_owners.createAdd Repo Ownerwritelangsmith.repos_owners.deleteRemove Repo Ownerdestructivelangsmith.repos_owners.getList Repo Ownersread
Service accounts3
langsmith.service_accounts.createCreate Service Accountwritelangsmith.service_accounts.deleteDelete Service Accountdestructivelangsmith.service_accounts.listGet Service Accountsread
Audit logs2
langsmith.audit_logs.listGet Audit Logsreadlangsmith.audit_logs_operations.getList Audit Log Operationsread
Info2
langsmith.info.getGet server inforeadlangsmith.info.healthGet Health Inforead
Integrations2
langsmith.agent_builder_integrations.getGet Agent Builder integrations settingsreadlangsmith.agent_builder_integrations.updateUpdate Agent Builder integrations settingswrite
Productfeedback2
langsmith.platform_product_feedbacks.create[Alpha] Submit product feedbackwritelangsmith.platform_product_feedbacks.get[Alpha] Get product feedbackread
Sessions2
langsmith.platform_sessions_agent_versions.listList agent versions for a projectreadlangsmith.sessions_resolutions.get[Beta] Resolve an address to its tracing projectread
Settings2
langsmith.settings.getGet Settingsreadlangsmith.settings.handleSet Tenant Handlewrite
Usage2
langsmith.fleet_usage_agents.listList Fleet agent costsreadlangsmith.fleet_usage_users.listList Fleet user costsread
Ace1
langsmith.ace.executeExecutewrite
Backfills1
langsmith.platform_ops_backfills.restartRestart a backfill jobwrite
Experiments1
langsmith.runs_experiments.evaluateEvaluate Experiment Adhocwrite
Fleet orgs1
langsmith.fleet_orgs.listList organizationsread
Fleet tenants1
langsmith.fleet_orgs_tenants.listList tenantsread
Fleet threads1
langsmith.fleet_threads.sandbox_activationActivate a thread sandboxwrite
Likes1
langsmith.likes.createLike Repowrite
Me1
langsmith.me_providers.getGet the authenticated user's provider user IDread
Organizations1
langsmith.platform_orgs_current_info.getGet current organization inforead
Prompts1
langsmith.prompts.invoke_promptInvoke Promptwrite
This index shows a sample of each area. All 530 actions, with their inputs and prices, are in the catalogue, which a free sandbox key can search.
Questions
The LangSmith MCP server, answered.
Is there a LangSmith MCP server for Claude?
Yes. actionlake is an MCP gateway: a remote MCP server that gives Claude, or another MCP client, 530 LangSmith actions across orgs, sandboxes, workspaces and annotation queues, through the same eight tools it uses for every other connector. actionlake is independent; it is not made or endorsed by LangSmith.
What do I need to connect LangSmith?
LangSmith API key: in LangSmith open Settings > API Keys and create a Personal Access Token (lsv2_pt_...) or a…. Plus your host, your organization id and your workspace id. The free call account { op: "connections.requirements", service: "langsmith" } lists exactly what to paste.
Can an AI agent delete or change things in LangSmith?
Only if its key allows it, and only with an explicit confirmation. 102 LangSmith actions are destructive, including delete Datasets, delete Workspace and delete Service Account. Each runs only with confirm: true. Under the human confirm policy, or an approval rule on the key, the run waits until a named person approves it.
Will an AI agent use up my LangSmith API limit?
actionlake paces every call to the limits in the LangSmith service file: 600 calls a minute per connection. Repeated reads are answered from cache (189 LangSmith actions can be), which never reaches LangSmith.
What does a LangSmith action cost?
One upstream call, the only unit actionlake bills. A list that pages bills one call per page (530 LangSmith actions page). Cache hits, searches, dry runs and calls LangSmith refused with 401, 403, 429 or a 5xx are free. The Free plan includes 100,000 calls a month with no card. Paid plans start at US$49 a month for 250,000 calls, with overage from US$0.30 down to US$0.18 per 1,000.
Which LangSmith API does it cover?
The LangSmith API (spec 0.1.0, OpenAPI 3.1.0) at api.smith.langchain.com by default, or the base URL set when you connect. It is built from LangSmith's documentation as read on 23 October 2026. 530 actions in 63 areas, each one in the signed service file (version 1.0.0).
Does actionlake keep my LangSmith data, and where?
actionlake processes and stores data in Sydney, Australia; there is no US region yet. Reads may be cached for up to 5 minutes, and a write clears the reads it affects. Each run's request and response is kept, sealed, for your plan's trace window: 1 day on Free, 3 days on Starter, 7 days on Pro, 14 days on Team, 30 days on Business and 30 days on Enterprise. Your LangSmith credential is sealed under your tenant's key, never logged and never returned. Your traffic is not used to train models.
Which AI clients can use it?
Claude Code, tested by us end to end, and the Claude app as a custom connector, tested by us with an existing key. Other MCP clients that support remote servers over Streamable HTTP (MCP revisions 2025-06-18 and 2025-11-25) and OAuth dynamic client registration, or a bearer header, should connect the same way; we have not tested them. Or plain REST, under the same action names.
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