--- title: Prepare live tail --- [Skip to content](#_top) [API Reference](https://developers.cloudflare.com/api/typescript) [Workers](https://developers.cloudflare.com/api/typescript/resources/workers) [Observability](https://developers.cloudflare.com/api/typescript/resources/workers/subresources/observability) [Telemetry](https://developers.cloudflare.com/api/typescript/resources/workers/subresources/observability/subresources/telemetry) Copy Markdown Open in **Claude**Open in **ChatGPT**Open in **Cursor** --- **Copy Markdown****View as Markdown** # Prepare live tail client.workers.observability.telemetry.liveTail(TelemetryLiveTailParams {account\_id, filterCombination, filters, scriptId } params, RequestOptionsoptions?): [TelemetryLiveTailResponse]() {wsUrl } POST/accounts/{account\_id}/workers/observability/telemetry/live-tail Prepare websocket server for live tail. ##### Security

API Email + API Key

The previous authorization scheme for interacting with the Cloudflare API, used in conjunction with a Global API key. **Example:**X-Auth-Email: user@example.com The previous authorization scheme for interacting with the Cloudflare API. When possible, use API tokens instead of Global API keys. **Example:**X-Auth-Key: 144c9defac04969c7bfad8efaa8ea194

API Token

The preferred authorization scheme for interacting with the Cloudflare API. Create a token. **Example:**Authorization: Bearer Sn3lZJTBX6kkg7OdcBUAxOO963GEIyGQqnFTOFYY

User Service Key

Used when interacting with the Origin CA certificates API. View/change your key. **Example:**

X-Auth-User-Service-Key: v1.0-144c9defac04969c7bfad8ef-631a41d003a32d25fe878081ef365c49503f7fada600da935e2851a1c7326084b85cbf6429c4b859de8475731dc92a9c329631e6d59e6c73da7b198497172b4cefe071d90d0f5d2719

##### Accepted Permissions (at least one required) `Workers Observability Write` ##### ParametersExpand Collapse

params: TelemetryLiveTailParams {account\_id, filterCombination, filters, scriptId }

account\_id: string Path param: Your Cloudflare account ID. Link to this property

filterCombination?: "and"| "or"| "AND"| "OR" Body param: Set a flag to describe how to combine the filters on the query.

One of the following: "and" Link to this property "or" Link to this property "AND" Link to this property "OR" Link to this property

Link to this property

filters?: Array<UnionMember0 {filterCombination, filters, kind } | WorkersObservabilityFilterLeaf {key, operation, type, 2 more } > Body param: Apply filters to the query. Supports nested groups via kind: ‘group’.

One of the following:

UnionMember0 {filterCombination, filters, kind }

filterCombination: "and"| "or"| "AND"| "OR"

One of the following: "and" Link to this property "or" Link to this property "AND" Link to this property "OR" Link to this property

Link to this property

filters: Array<UnionMember0 {filterCombination, filters, kind } | WorkersObservabilityFilterLeaf {key, operation, type, 2 more } >

One of the following:

UnionMember0 {filterCombination, filters, kind }

filterCombination: "and"| "or"| "AND"| "OR"

One of the following: "and" Link to this property "or" Link to this property "AND" Link to this property "OR" Link to this property

Link to this property filters: Array<unknown> Link to this property kind: "group" Link to this property

Link to this property

WorkersObservabilityFilterLeaf {key, operation, type, 2 more } A filter condition applied to query results. Use the keys and values endpoints to discover available fields and their values before constructing filters.

key: string Filter field name. Use verified keys from previous query results or the keys endpoint. Common keys include $metadata.service, $metadata.origin, $metadata.trigger, $metadata.message, and $metadata.error. Link to this property

operation: "includes"| "not\_includes"| "starts\_with"| 27 more Comparison operator. String operators: includes, not\_includes, starts\_with, ends\_with, regex. Existence: exists, is\_null. Set membership: in, not\_in (comma-separated values). Numeric: eq, neq, gt, gte, lt, lte.

Link to this property

type: "string"| "number"| "boolean" Data type of the filter field. Must match the actual type of the key being filtered.

One of the following: "string" Link to this property "number" Link to this property "boolean" Link to this property

Link to this property kind?: "filter" Discriminator for leaf filter nodes. Always ‘filter’ when present; may be omitted. Link to this property

value?: string| number| boolean Comparison value. Must match actual values in your data — verify with the values endpoint. Ensure the value type (string/number/boolean) matches the field type. String comparisons are case-sensitive. Regex uses RE2 syntax (no lookaheads/lookbehinds).

One of the following: string Link to this property number Link to this property boolean Link to this property

Link to this property

Link to this property kind: "group" Link to this property

Link to this property

type: "string"| "number"| "boolean" Data type of the filter field. Must match the actual type of the key being filtered.

One of the following: "string" Link to this property "number" Link to this property "boolean" Link to this property

Link to this property kind?: "filter" Discriminator for leaf filter nodes. Always ‘filter’ when present; may be omitted. Link to this property

One of the following: string Link to this property number Link to this property boolean Link to this property

Link to this property

Link to this property scriptId?: string Body param Link to this property

[Link to this property](<#(resource)%20workers.observability.telemetry%20%3E%20(method)%20live_tail%20%3E%20(params)%20default>) ##### ReturnsExpand Collapse

TelemetryLiveTailResponse {wsUrl }

wsUrl: string WebSocket URL clients connect to in order to stream live tail events. formaturi Link to this property

[Link to this property](<#(resource)%20workers.observability.telemetry%20%3E%20(model)%20telemetry_live_tail_response%20%3E%20(schema)>) ### Prepare live tail TypeScript HTTPTypeScriptPythonGoTerraform ``` import Cloudflare from 'cloudflare'; const client = new Cloudflare({ apiEmail: process.env['CLOUDFLARE_EMAIL'], // This is the default and can be omitted apiKey: process.env['CLOUDFLARE_API_KEY'], // This is the default and can be omitted }); const response = await client.workers.observability.telemetry.liveTail({ account_id: 'account_id', }); console.log(response.wsUrl); ``` 200 example ``` { "errors": [ { "message": "message" } ], "messages": [ { "message": "Successful request" } ], "result": { "wsUrl": "https://example.com" }, "success": true } ``` ##### Returns Examples 200 example ``` { "errors": [ { "message": "message" } ], "messages": [ { "message": "Successful request" } ], "result": { "wsUrl": "https://example.com" }, "success": true } ```