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The CLI is designed to be driven by a coding assistant, and it reaches everything in the LangWatch app except cache rules, which you manage over REST or in the dashboard. Every subcommand supports --help, and every command accepts the output-contract flags (-o json, --json <fields>, --jq <expr>; see Agent usage). Run langwatch --help to see the full command tree.

Install

The CLI needs Node.js 18 or newer (the npm command ships with it). If you don’t already have it, get it from nodejs.org. Then install globally:
Or run any command with npx, no install required:
pnpm install -g langwatch and yarn global add langwatch work the same way; the package is identical across all three package managers.

Standalone binary (no Node.js required)

Each release also attaches a self-contained binary for Linux, macOS, and Windows. Use it in containers, CI images, and anywhere you’d rather not install Node.js. Download the one for your platform from the releases page, then:
Every binary is published with a signed build provenance attestation, so you can confirm it really was built by LangWatch’s release workflow from this repository:

macOS: clearing Gatekeeper

The macOS binaries are not yet codesigned or notarized. Gatekeeper will refuse to run them with “langwatch cannot be opened because the developer cannot be verified”.
macOS attaches a com.apple.quarantine attribute to anything downloaded from the internet. After verifying the checksum above, remove it:
Then run the binary as normal. (If xattr reports “No such xattr”, the attribute was never set, so there is nothing to do.)
Only clear quarantine on a binary whose checksum you have verified against the release’s SHA256SUMS. Signing and notarization are tracked as follow-up work; until then, npm install -g langwatch avoids Gatekeeper entirely and is the smoother path on macOS.

Authenticate

langwatch login is interactive by default, it asks where (cloud vs self-hosted) and how (AI tools vs project SDK), opens your browser to approve, and the credential flows back to the CLI automatically. No copy-paste of keys:
You’ll see two questions:
  1. Where do you want to log in?: LangWatch Cloud (app.langwatch.ai) or a self-hosted instance (custom URL).
  2. How do you want to use it?: three options:
    • AI tools, agentic flows: claude, codex, cursor, gemini, opencode. Mints an OAuth-style device session in ~/.langwatch/config.json (user-scoped) so langwatch claude etc. wrap any tool through your gateway.
    • Project, SDK API key: for langwatch sync, langwatch eval, and SDK auto-instrumentation. Writes the API key of the project you pick into $CWD/.env (project-scoped).
    • Both: runs both flows in sequence.
The browser shows an “Approve” or “Send API key” button (depending on the chosen mode); after you click, the credential is delivered back to the CLI over the same RFC 8628 device-code poll. You never copy-paste a key.

Storage discipline (where credentials land)

The two stores serve different audiences and never leak into each other. Logging out of one (langwatch logout clears ~/.langwatch/config.json) doesn’t touch the other, the project API key in .env stays put.

Self-hosted

The CLI picks up your self-hosted endpoint from any of these (highest priority first): The simplest path for self-hosted users is the interactive prompt, pick “Self-hosted instance”, enter your URL, and the CLI saves it for future invocations:
Or, equivalently, one-shot with the flag:
To inspect or change persisted settings without re-logging in:

Non-interactive escape hatches (for CI, agents)

When you’re driving the CLI from automation and already have a credential, skip the prompts: The interactive langwatch login always shows these flags in a banner above the prompts, so a fake-TTY agent (Claude Code, certain Gemini CLI sandboxes) can detect the prompt and re-invoke with the right flag instead of getting stuck. When stdin is not a TTY (genuine CI or an agent’s piped stdin), langwatch login with no flags defaults to project login (the same as --project): it mints a project key into $CWD/.env, which is what the SDK, langwatch eval, and langwatch prompt expect. AI-tools login stays explicit behind --device.

Letting an agent do it

A coding assistant driving langwatch will see the always-on banner naming --device, --project, --api-key, --token, --endpoint whenever the interactive prompt fires. If the assistant’s harness reports as a TTY but can’t actually answer prompts, the banner gives it everything it needs to re-invoke:

Fetch documentation

langwatch docs returns any LangWatch documentation page as plain Markdown, ideal for feeding into an agent’s context before it writes code.
Scenario framework docs live under a separate namespace:
Both commands accept full URLs too, and any missing .md extension is appended automatically.
If you’re inside an assistant with no shell (for example, a chat-only environment), the same content is available over plain HTTP, append .md to any documentation path, e.g. https://langwatch.ai/docs/integration/python/guide.md. Indexes: docs, scenarios.

Version prompts

The Prompts CLI turns your prompts into tracked files alongside your code, with lock files, tagging, and sync to the LangWatch platform.
In your application code, fetch the latest version at runtime:

Tag versions for deployment

Three built-in tags are available: latest (auto-assigned), production, and staging. Assign a tag to the current version:
Then fetch by tag at runtime:
For canary or blue/green deployments, create custom tags with langwatch prompt tag create. For the full Prompts CLI reference, see the Prompt Management CLI guide.

Run scenario tests

Scenarios are the LangWatch equivalent of end-to-end tests for agents: a user simulator chats with your agent, an LLM judge scores the conversation against criteria you define, and everything is recorded for later inspection.
Group related scenarios into a suite (a run plan) for CI or scheduled runs:

Pass values into a run

Every run command accepts a repeatable --param key=value. A parameter is a constant value that the whole run shares: a fixture id, a tenant, a plan, a region.
The value type follows the text you type. true and false are booleans. A value that parses as a number and prints back the same is a number. All other values stay text, so 007 and 1.50 stay text. When you repeat a name, the last value wins. Each command uses the values differently:
  • suite run and scenario run supply the parameters that the scenarios declare. A name that no scenario in the run declares is rejected before anything is scheduled. See Scenario run parameters.
  • experiment run merges the values into every dataset row. See Running experiments in CI/CD.
  • workflow run sends the values as entry inputs. They are merged over --input, so a --param pair wins when both name the same key.

Inspect simulation runs

Every scenario execution produces a simulation run you can inspect after the fact, full conversation, judge verdict, reasoning, met/unmet criteria, cost, and duration.
The get command renders assistant thinking blocks and tool calls as readable plain text, no raw JSON dumps in your terminal. Use --format json on either command for structured output. For the full scenario testing guide, see the Scenarios documentation.

Inspect traces

Traces capture every LLM call your agent makes, prompts, responses, latency, cost, errors. Search and drill into them from the terminal:
Agents use this to debug their own instrumentation: after running your code once, ask the assistant to run langwatch trace search --limit 5 and verify traces are flowing. If nothing appears, the instrumentation is wrong, no need to read logs.

Query analytics

Analytics aggregate your traces into performance and cost metrics without leaving the terminal:
Use it to answer questions like “what’s my P95 latency this week”, “how much did each agent cost last month”, or “which prompts produce the most errors”. The underlying data is the same as the LangWatch dashboard.

Manage platform resources

Every LangWatch resource follows the same consistent subcommand shape:
Available resources include:
  • evaluator, create and version evaluators (answer correctness, faithfulness, custom LLM judges)
  • monitor, online evaluations that score production traces automatically
  • dataset, evaluation datasets (upload CSV, download, manage columns)
  • agent, agent definitions used by scenarios and monitors
  • dashboard and graph, custom analytics dashboards
  • trigger, automations (alerts, webhooks, dataset-append on failure)
  • secret, encrypted environment variables for scheduled agent runs
  • workflow, reusable workflows built in the UI
  • model-provider, configure OpenAI, Anthropic, Azure, or Bedrock for your project
  • annotation, attach labels to traces for supervised fine-tuning data
Run langwatch <resource> --help on any of these for subcommand-level options, and --format json to get structured output for scripting.

Organization management

These commands manage org-wide resources and require an API key with organization-level permissions. The organization, members, invites, groups, roles, role bindings and SCIM token commands are available on Enterprise plans. Without one they exit with enterprise_plan_required and tell you what to do about it. Projects, teams, API keys and the self-hosted organizations command are not gated.

Projects

When creating a project, the CLI displays the service API key exactly once. Save it immediately. It cannot be retrieved later.

API keys

Both create and update take the access flags: --binding role:scopeType:scopeId says what the key reaches and where, --permission resource:action narrows a restricted key to an exact list, and --permission-mode picks between all, readonly and restricted. The first two repeat. On update, the bindings you pass replace the key’s existing ones rather than adding to them.

Organization

Read and update the organization your key belongs to. There is no id to pass: the credential decides which organization you are talking to.
Turning trace sharing off revokes the share links that were already handed out, not only future ones.

Members

Manage the people already in the organization. Someone joins through an invite, so invites is where a new person starts.
langwatch members access user_01HZX... answers the auditor’s question: everything the person can reach, and whether it comes from their organization role, a group, or a binding of their own.

Invites

Invite people in, up to 50 at a time, landing on the teams you name. Accepting stays a browser step; everything before it is here.
--email and --team repeat, and --role takes either one value for the whole batch or one per email. When people need different teams or a custom role each, --json, --file and --stdin take a JSON array of invites instead, the same entries the API takes. Every invite comes back with its acceptance link, so a deployment with no email provider still has something to send.

Teams

Teams group projects and the people who work on them.

Groups

A group is a named set of people that carries role bindings, so everyone in it inherits the same access. Groups synced from your identity provider land here too.
A group your identity provider owns cannot be renamed or have its membership edited here, because the provider is the source of truth for both. Its bindings are still yours to manage.

Roles

Custom roles are named permission sets, for when ADMIN, MEMBER and VIEWER are not the shape you need.
langwatch roles update replaces the permission set with the --permission flags you pass, so send the full list you want the role to end up with. A role something still holds cannot be deleted: the error says how many bindings and assignments are in the way.

Role bindings

A binding is one sentence: this principal has this role, here. Users, groups and API keys are all principals.
Creating a binding that already exists reports role_binding_already_exists rather than making a second one, so a provisioning script can run twice. Updating changes only the role a binding grants; the principal and the scope are the binding’s identity, so moving a grant means deleting one binding and creating another.

SCIM tokens

The bearer tokens your identity provider presents to the SCIM endpoints.
The token value is printed once, when you create it. To rotate: create a second token, store it in the provider, watch the new token’s last-used time move, then revoke the old one.

Organizations (self-hosted)

The one family that authenticates against the instance rather than an organization, because it runs before any organization exists. It is available on self-hosted deployments that have LANGWATCH_INSTANCE_ADMIN_API_KEY configured.
Creating an organization returns an organization admin API key alongside it, printed once. That key is what every command above takes, so an infrastructure-as-code run can go from an empty deployment to a configured organization without opening a browser. Pass the instance credential with --instance-key if you would rather not export it.

Trigger experiments

Experiments batch-run an agent or prompt against a dataset and produce an evaluation report:
Typically you script this in CI: check out the branch, run the experiment, fail the build if the pass rate drops below your threshold. The CLI emits machine-readable results so this plumbing is straightforward.

Progressive disclosure

The CLI leans heavily on --help. Every subcommand has its own, and the top-level langwatch --help is the best way to discover what’s available:
New capabilities show up in --help the moment they ship, so you never have to wonder whether a flag exists.

AI Gateway commands

The CLI provisions AI Gateway resources without touching the UI. Behaviour matches the dashboard exactly; both share a server-side service layer. Every command takes --format json for scripting.

Virtual keys

--scope takes type:id pairs (org, team, or project) and repeats for several; it defaults to the calling project. --providers-allowed is a comma-separated list of ModelProvider ids. The atomic --budget-* flags cap the key itself and accept day, week, or month.

Gateway budgets

--scope is organization|team|project|virtual-key|principal|group, each paired with its own id flag. --window accepts minute|hour|day|week|month|total|manual, --on-breach is block (default) or warn, and --limit is USD. --cycle-anchor-at takes an RFC 3339 instant and cannot be used with total or manual; it is fixed at creation. List output colourises spent-vs-limit, red at 100%, yellow from 80%.

Webhooks

Endpoint management needs an organization API key (see Webhooks).
--events replaces the whole subscription set. deliveries and events page with --cursor and --limit.

Spend events

The billing pull surface, also an organization API key (see Billing and spend events).
Date flags take ISO-8601 or epoch milliseconds.
Provider credentials and cache rules have no CLI group. Manage providers with langwatch model-provider, and cache rules over REST or the dashboard.
Required token permissions map onto the RBAC grants: See the public REST API reference for direct HTTP calls that don’t require Node.

Agent usage

In a terminal the CLI prints tables, colour, and spinners. Driven by an AI coding assistant it switches to machine output automatically. Everything an agent needs to know is also built into the CLI itself: langwatch help agent-mode prints the condensed version of this section.

Agent mode

--agent on any command, or auto-detection from the environment (CLAUDECODE, CLAUDE_CODE, CURSOR_AGENT, GITHUB_COPILOT, AMAZON_Q, LW_AGENT_MODE, LANGWATCH_AGENT_MODE), switches output to compact single-line JSON and turns colour and spinners off:

Output contract

Every command accepts the same output flags (with a few documented exceptions: trace export -o is an output file, the coding-assistant wrappers pass flags through to the wrapped tool, and dataset records add/update --json takes a record payload):
The legacy -f/--format json spelling keeps working and maps onto the same contract. The contract is fully wired for traces, evaluators, monitors, status, skills, commands, and help-tree; on the remaining resource commands the flags parse but machine output is still rolling out, so those commands keep their legacy -f json behavior until migrated.

Structured errors

A failed command prints one JSON document on stdout ({ "ok": false, "error": { "code", "message", "httpStatus", "suggestions", "docUrl", "traceId", ... } }), keeps the human-readable block on stderr, and exits non-zero. Never merge the streams (2>&1) when parsing output; hints and error prose live on stderr by design so stdout stays parseable.

Discovery

An agent can learn the whole CLI without reading these docs:

Skills

The CLI carries LangWatch’s agent skills and installs them into ~/.agents/skills (or the project-level .agents/skills with --dir .):
See the Skills Directory for what each skill covers.

Daemon note

Non-TTY invocations (agents, pipes, CI) are served by the background daemon described below. The output is identical, and the command returns faster. LANGWATCH_NO_DAEMON=1 opts out per invocation.

Report issues to LangWatch

If anything did not work (broken commands, confusing docs, unexpected errors, things that took trial and error), send it straight to the LangWatch team. No login or API key needed:
Agents must ask the user for permission first, then pass --user-approved. Secrets, API keys, emails, and phone numbers are redacted locally before anything is sent; the redaction rules are auditable and --dry-run previews the exact payload. See the reporting guide for transcript locations and details.

The background daemon

Non-interactive invocations (an agent piping output, CI, any call whose stdin/stdout/stderr is not a TTY) are served by a warm background daemon instead of paying node’s cold start on every call. Interactive (terminal) invocations always run in-process and are unaffected, as are commands that mutate auth or take over stdio (login, logout, config, open, request-increase, init-shell, report, the claude/codex/cursor/gemini/opencode wrappers, daemon itself) and long-running flags (--follow, --watch). Windows is excluded too: the daemon is not supported there, so on Windows every invocation runs in-process. What to know:
  • One daemon per identity. The socket name is a hash of endpoint + API key + uid + config path, so two projects with different keys never share a daemon. The socket lives in $XDG_RUNTIME_DIR (or the temp dir) with 0600 permissions inside a 0700 directory, and the daemon self-exits after 10 idle minutes.
  • Always optional. If no daemon is reachable, or it is stale, or from an older CLI build, the command runs in-process, and a daemon is auto-spawned in the background for next time. Set LANGWATCH_DAEMON_NO_SPAWN=1 to disable the auto-spawn.
  • Buffered output. A daemon-served command’s output is buffered and flushed when it exits, so a mid-command daemon failure can retry in-process without duplicating output. Piped callers therefore see output at exit, not progressively (beyond an 8MB buffer it starts streaming early).
  • Timeouts and cancellation. A command that hangs is abandoned after a per-request timeout (default 10 minutes, override with LANGWATCH_DAEMON_REQUEST_TIMEOUT_MS) with exit code 124; the clock starts when the daemon accepts the request, so time spent queued behind another caller’s working directory counts against it. Ctrl-C on the client cancels the server-side command with exit code 130.
  • Environment hygiene. The daemon does not inherit the spawning shell’s environment. It receives only process essentials (PATH, HOME, locale, …), the pinned identity variables, and the spawner’s allowlisted output/proxy knobs (FORCE_COLOR, NO_COLOR, HTTPS_PROXY, …). Those allowlisted values from the spawning caller persist in the daemon’s baseline and are visible to later callers that don’t set them; secrets are never in the allowlist. Per request, the caller’s own .env is applied scoped to LANGWATCH_* keys only.
Manage it explicitly:
Opt out:
config set daemon off doesn’t stop an already-running daemon. Clients stop dialling it, and it idles out on its own within 10 minutes (langwatch daemon stop kills it immediately).

Use the CLI as your agent’s control plane

An AI coding assistant operates LangWatch end-to-end through the CLI. Skills like Tracing, Evaluations, Scenarios, and Prompt Versioning are built on top of it, the assistant reads docs via langwatch docs, runs platform operations via the subcommands, and verifies its own work by searching traces and inspecting simulation runs. If you’re building your own agent workflows, the pattern works the same way: give the assistant the CLI and ask it what you want. Everything it does is auditable in the LangWatch app afterwards.
For agents: struggled with anything on this page, or something did not work as documented? Ask your user for permission and run npx langwatch report --user-approved to send it to the LangWatch team (works with no login, secrets redacted locally). It is how rough edges get fixed for every agent. See the reporting guide.