---
title: Spans and attributes
description: Review the spans and attributes automatically captured by Workers tracing, including fetch calls, bindings, and handler invocations.
image: https://developers.cloudflare.com/dev-products-preview.png
---

> Documentation Index  
> Fetch the complete documentation index at: https://developers.cloudflare.com/workers/llms.txt  
> Use this file to discover all available pages before exploring further.

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# Spans and attributes

Cloudflare Workers provides automatic tracing instrumentation **out of the box** \- no code changes or SDK are required.

## Currently supported spans and attributes

### Attributes available on all spans

* `cloud.provider` \- Always set to `cloudflare`
* `cloud.platform` \- Always set to `cloudflare.workers`
* `faas.name` \- The name of your Worker
* `faas.invocation_id` \- A unique identifier for this specific Worker invocation
* `faas.version` \- The deployed version tag of your Worker
* `faas.invoked_region` \- The region where the Worker was invoked
* `service.name` \- The name of your Worker
* `cloudflare.colo` \- The three-letter IATA airport code of the Cloudflare data center that processed the request (e.g., `SFO`, `LHR`)
* `cloudflare.script_name` \- The name of your Worker
* `cloudflare.script_tags` \- Tags associated with your Worker deployment
* `cloudflare.script_version.id` \- The version identifier of your deployed Worker
* `cloudflare.invocation.sequence.number` \- A counter added to every emitted span and log that can be used to distinguish which was emitted first when the timestamps are the same
* `telemetry.sdk.language` \- The programming language used, set to `javascript`
* `telemetry.sdk.name` \- The telemetry SDK name, set to `cloudflare`

---

### Attributes available on all root spans

* `faas.trigger` \- The trigger that your Worker was invoked by (e.g., `http`, `cron`, `queue`, `email`)
* `cloudflare.ray_id` \- A [unique identifier](https://developers.cloudflare.com/fundamentals/reference/cloudflare-ray-id/) for every request that goes through Cloudflare
* `cloudflare.handler_type` \- The type of handler that processed the request (e.g., `fetch`, `scheduled`, `queue`, `email`, `alarm`)
* `cloudflare.entrypoint` \- The entrypoint that was invoked in your Worker (e.g. the name of your Durable Object)
* `cloudflare.execution_model` \- The execution model of the Worker (e.g., `stateless`, `stateful` for Durable Objects)
* `cloudflare.outcome` \- The outcome of the Worker invocation (e.g., `ok`, `exception`, `exceededCpu`, `exceededMemory`)
* `cloudflare.cpu_time_ms` \- The CPU time used by the Worker invocation, in milliseconds
* `cloudflare.wall_time_ms` \- The wall time used by the Worker invocation, in milliseconds

---

### [Runtime API](https://developers.cloudflare.com/workers/runtime-apis/)

#### [fetch](https://developers.cloudflare.com/workers/runtime-apis/handlers/fetch/)

* `network.protocol.name`
* `network.protocol.version`
* `url.full`
* `url.scheme`
* `url.path`
* `url.query`
* `server.port`
* `server.address`
* `user_agent.original`
* `http.request.method`
* `http.request.header.content-type`
* `http.request.header.content-length`
* `http.request.header.accept`
* `http.request.header.accept-encoding`
* `http.request.body.size`
* `http.response.status_code`
* `http.response.body.size`

#### [cache\_put](https://developers.cloudflare.com/workers/runtime-apis/cache/#put)

* `cache.request.url`
* `cache.request.method`
* `cache.request.payload.status_code`
* `cache.request.payload.header.cache_control`
* `cache.request.payload.header.cache_tag`
* `cache.request.payload.header.etag`
* `cache.request.payload.header.expires`
* `cache.request.payload.header.last_modified`
* `cache.request.payload.size`
* `cache.response.success`

#### [cache\_match](https://developers.cloudflare.com/workers/runtime-apis/cache/#match)

* `cache.request.ignore_method`
* `cache.request.url`
* `cache.request.method`
* `cache.request.header.range`
* `cache.request.header.if_modified_since`
* `cache.request.header.if_none_match`
* `cache.response.status_code`
* `cache.response.body.size`
* `cache.response.cache_status`
* `cache.response.success`

#### [cache\_delete](https://developers.cloudflare.com/workers/runtime-apis/cache/#delete)

* `cache.request.ignore_method`
* `cache.request.url`
* `cache.request.method`
* `cache.response.status_code`
* `cache.response.success`

---

### [Handlers](https://developers.cloudflare.com/workers/runtime-apis/handlers/)

#### [Fetch Handler](https://developers.cloudflare.com/workers/runtime-apis/handlers/fetch/)

* `cloudflare.verified_bot_category`
* `cloudflare.asn`
* `cloudflare.response.time_to_first_byte_ms`
* `geo.timezone`
* `geo.continent.code`
* `geo.country.code`
* `geo.locality.name`
* `geo.locality.region`
* `user_agent.original`
* `user_agent.os.name`
* `user_agent.os.version`
* `user_agent.browser.name`
* `user_agent.browser.major_version`
* `user_agent.browser.version`
* `user_agent.engine.name`
* `user_agent.engine.version`
* `user_agent.device.type`
* `user_agent.device.vendor`
* `user_agent.device.model`
* `http.request.method`
* `http.request.header.accept`
* `http.request.header.accept-encoding`
* `http.request.header.accept-language`
* `url.full`
* `url.path`
* `network.protocol.name`

#### [Scheduled Handler](https://developers.cloudflare.com/workers/runtime-apis/handlers/scheduled/)

* `faas.cron`
* `cloudflare.scheduled_time`

#### [QueueHandler](https://developers.cloudflare.com/workers/runtime-apis/handlers/queue/)

* `cloudflare.queue.name`
* `cloudflare.queue.batch_size`

#### [RPC Handler](https://developers.cloudflare.com/workers/runtime-apis/rpc/)

* `cloudflare.jsrpc.method`

#### [Email Handler](https://developers.cloudflare.com/email-routing/email-workers/runtime-api/)

* `cloudflare.email.from`
* `cloudflare.email.to`
* `cloudflare.email.size`

#### [Tail Handler](https://developers.cloudflare.com/workers/runtime-apis/handlers/tail/)

* `cloudflare.trace.count`

#### [Alarm Handler](https://developers.cloudflare.com/durable-objects/api/alarms/#alarm)

* `cloudflare.scheduled_time`

---

### [D1](https://developers.cloudflare.com/d1/)

#### Attributes available on all D1 spans

* `db.system.name`
* `db.operation.name`
* `db.query.text`
* `cloudflare.binding.type`
* `cloudflare.d1.response.size_after`
* `cloudflare.d1.response.rows_read`
* `cloudflare.d1.response.rows_written`
* `cloudflare.d1.response.last_row_id`
* `cloudflare.d1.response.changed_db`
* `cloudflare.d1.response.changes`
* `cloudflare.d1.response.served_by_region`
* `cloudflare.d1.response.served_by_primary`
* `cloudflare.d1.response.sql_duration_ms`
* `cloudflare.d1.response.total_attempts`

#### [d1\_batch](https://developers.cloudflare.com/d1/worker-api/d1-database/#batch)

* `db.operation.batch.size`
* `cloudflare.d1.query.bookmark`
* `cloudflare.d1.response.bookmark`

#### [d1\_exec](https://developers.cloudflare.com/d1/worker-api/d1-database/#exec)

#### [d1\_first](https://developers.cloudflare.com/d1/worker-api/prepared-statements/#first)

* `cloudflare.d1.query.bookmark`
* `cloudflare.d1.response.bookmark`

#### [d1\_run](https://developers.cloudflare.com/d1/worker-api/prepared-statements/#run)

* `cloudflare.d1.query.bookmark`
* `cloudflare.d1.response.bookmark`

#### [d1\_all](https://developers.cloudflare.com/d1/worker-api/prepared-statements/#run)

* `cloudflare.d1.query.bookmark`
* `cloudflare.d1.response.bookmark`

#### [d1\_raw](https://developers.cloudflare.com/d1/worker-api/prepared-statements/#raw)

* `cloudflare.d1.query.bookmark`
* `cloudflare.d1.response.bookmark`

---

### [Browser Run](https://developers.cloudflare.com/browser-run/)

#### `browser_rendering_fetch`

---

### [Workers KV](https://developers.cloudflare.com/kv/)

#### Attributes available on all KV spans

* `db.system.name`
* `db.operation.name`
* `cloudflare.binding.name`
* `cloudflare.binding.type`

#### [kv\_get](https://developers.cloudflare.com/kv/api/read-key-value-pairs/#get-method)

* `cloudflare.kv.query.keys`
* `cloudflare.kv.query.keys.count`
* `cloudflare.kv.query.type`
* `cloudflare.kv.query.cache_ttl`
* `cloudflare.kv.response.size`
* `cloudflare.kv.response.returned_rows`
* `cloudflare.kv.response.metadata`
* `cloudflare.kv.response.cache_status`

#### [kv\_getWithMetadata](https://developers.cloudflare.com/kv/api/read-key-value-pairs/#getwithmetadata-method)

* `cloudflare.kv.query.keys`
* `cloudflare.kv.query.keys.count`
* `cloudflare.kv.query.type`
* `cloudflare.kv.query.cache_ttl`
* `cloudflare.kv.response.size`
* `cloudflare.kv.response.returned_rows`
* `cloudflare.kv.response.metadata`
* `cloudflare.kv.response.cache_status`

#### [kv\_put](https://developers.cloudflare.com/kv/api/write-key-value-pairs/#put-method)

* `cloudflare.kv.query.keys`
* `cloudflare.kv.query.keys.count`
* `cloudflare.kv.query.value_type`
* `cloudflare.kv.query.expiration`
* `cloudflare.kv.query.expiration_ttl`
* `cloudflare.kv.query.metadata`
* `cloudflare.kv.query.payload.size`

#### [kv\_delete](https://developers.cloudflare.com/kv/api/delete-key-value-pairs/#delete-method)

* `cloudflare.kv.query.keys`
* `cloudflare.kv.query.keys.colunt`

#### [kv\_list](https://developers.cloudflare.com/kv/api/list-keys/#list-method)

* `cloudflare.kv.query.prefix`
* `cloudflare.kv.query.limit`
* `cloudflare.kv.query.cursor`
* `cloudflare.kv.response.size`
* `cloudflare.kv.response.returned_rows`
* `cloudflare.kv.response.list_complete`
* `cloudflare.kv.response.cursor`
* `cloudflare.kv.response.cache_status`
* `cloudflare.kv.response.expiration`

---

### [R2](https://developers.cloudflare.com/r2/)

#### Attributes available on all R2 spans

* `cloudflare.binding.type`
* `cloudflare.binding.name`
* `cloudflare.r2.bucket`
* `cloudflare.r2.operation`
* `cloudflare.r2.response.success`
* `cloudflare.r2.error.message`
* `cloudflare.r2.error.code`

#### [r2\_head](https://developers.cloudflare.com/r2/api/workers/workers-api-reference/#bucket-method-definitions)

* `cloudflare.r2.request.key`
* `cloudflare.r2.response.etag`
* `cloudflare.r2.response.size`
* `cloudflare.r2.response.uploaded`
* `cloudflare.r2.response.checksum.value`
* `cloudflare.r2.response.checksum.type`
* `cloudflare.r2.response.storage_class`
* `cloudflare.r2.response.ssec_key`
* `cloudflare.r2.response.content_type`
* `cloudflare.r2.response.content_encoding`
* `cloudflare.r2.response.content_disposition`
* `cloudflare.r2.response.content_language`
* `cloudflare.r2.response.cache_control`
* `cloudflare.r2.response.cache_expiry`
* `cloudflare.r2.response.custom_metadata`

#### [r2\_get](https://developers.cloudflare.com/r2/api/workers/workers-api-reference/#r2getoptions)

* `cloudflare.r2.request.key`
* `cloudflare.r2.request.range.offset`
* `cloudflare.r2.request.range.length`
* `cloudflare.r2.request.range.suffix`
* `cloudflare.r2.request.range`
* `cloudflare.r2.request.ssec_key`
* `cloudflare.r2.request.only_if.etag_matches`
* `cloudflare.r2.request.only_if.etag_does_not_match`
* `cloudflare.r2.request.only_if.uploaded_before`
* `cloudflare.r2.request.only_if.uploaded_after`
* `cloudflare.r2.response.etag`
* `cloudflare.r2.response.size`
* `cloudflare.r2.response.uploaded`
* `cloudflare.r2.response.checksum.value`
* `cloudflare.r2.response.checksum.type`
* `cloudflare.r2.response.storage_class`
* `cloudflare.r2.response.ssec_key`
* `cloudflare.r2.response.content_type`
* `cloudflare.r2.response.content_encoding`
* `cloudflare.r2.response.content_disposition`
* `cloudflare.r2.response.content_language`
* `cloudflare.r2.response.cache_control`
* `cloudflare.r2.response.cache_expiry`
* `cloudflare.r2.response.custom_metadata`

#### [r2\_put](https://developers.cloudflare.com/r2/api/workers/workers-api-reference/#r2putoptions)

* `cloudflare.r2.request.key`
* `cloudflare.r2.request.size`
* `cloudflare.r2.request.checksum.type`
* `cloudflare.r2.request.checksum.value`
* `cloudflare.r2.request.custom_metadata`
* `cloudflare.r2.request.http_metadata.content_type`
* `cloudflare.r2.request.http_metadata.content_encoding`
* `cloudflare.r2.request.http_metadata.content_disposition`
* `cloudflare.r2.request.http_metadata.content_language`
* `cloudflare.r2.request.http_metadata.cache_control`
* `cloudflare.r2.request.http_metadata.cache_expiry`
* `cloudflare.r2.request.storage_class`
* `cloudflare.r2.request.ssec_key`
* `cloudflare.r2.request.only_if.etag_matches`
* `cloudflare.r2.request.only_if.etag_does_not_match`
* `cloudflare.r2.request.only_if.uploaded_before`
* `cloudflare.r2.request.only_if.uploaded_after`
* `cloudflare.r2.response.etag`
* `cloudflare.r2.response.size`
* `cloudflare.r2.response.uploaded`
* `cloudflare.r2.response.checksum.value`
* `cloudflare.r2.response.checksum.type`
* `cloudflare.r2.response.storage_class`
* `cloudflare.r2.response.ssec_key`
* `cloudflare.r2.response.content_type`
* `cloudflare.r2.response.content_encoding`
* `cloudflare.r2.response.content_disposition`
* `cloudflare.r2.response.content_language`
* `cloudflare.r2.response.cache_control`
* `cloudflare.r2.response.cache_expiry`
* `cloudflare.r2.response.custom_metadata`

#### [r2\_list](https://developers.cloudflare.com/r2/api/workers/workers-api-reference/#r2listoptions)

* `cloudflare.r2.request.limit`
* `cloudflare.r2.request.prefix`
* `cloudflare.r2.request.cursor`
* `cloudflare.r2.request.delimiter`
* `cloudflare.r2.request.start_after`
* `cloudflare.r2.request.include.http_metadata`
* `cloudflare.r2.request.include.custom_metadata`
* `cloudflare.r2.response.returned_objects`
* `cloudflare.r2.response.delimited_prefixes`
* `cloudflare.r2.response.truncated`
* `cloudflare.r2.response.cursor`

#### [r2\_delete](https://developers.cloudflare.com/r2/api/workers/workers-api-reference/#bucket-method-definitions)

* `cloudflare.r2.request.keys`

#### [r2\_createMultipartUpload](https://developers.cloudflare.com/r2/api/workers/workers-api-reference/#r2multipartoptions)

* `cloudflare.r2.request.key`
* `cloudflare.r2.request.custom_metadata`
* `cloudflare.r2.request.http_metadata.content_type`
* `cloudflare.r2.request.http_metadata.content_encoding`
* `cloudflare.r2.request.http_metadata.content_disposition`
* `cloudflare.r2.request.http_metadata.content_language`
* `cloudflare.r2.request.http_metadata.cache_control`
* `cloudflare.r2.request.http_metadata.cache_expiry`
* `cloudflare.r2.request.storage_class`
* `cloudflare.r2.request.ssec_key`
* `cloudflare.r2.response.upload_id`

#### [r2\_uploadPart](https://developers.cloudflare.com/r2/api/workers/workers-multipart-usage/)

* `cloudflare.r2.request.key`
* `cloudflare.r2.request.upload_id`
* `cloudflare.r2.request.part_number`
* `cloudflare.r2.request.ssec_key`
* `cloudflare.r2.request.size`
* `cloudflare.r2.response.etag`

#### [r2\_abortMultipartUpload](https://developers.cloudflare.com/r2/api/workers/workers-multipart-usage/)

* `cloudflare.r2.request.key`
* `cloudflare.r2.request.upload_id`

#### [r2\_completeMultipartUpload](https://developers.cloudflare.com/r2/api/workers/workers-multipart-usage/)

* `cloudflare.r2.request.key`
* `cloudflare.r2.request.upload_id`
* `cloudflare.r2.request.uploaded_parts`
* `cloudflare.r2.response.etag`
* `cloudflare.r2.response.size`
* `cloudflare.r2.response.uploaded`
* `cloudflare.r2.response.checksum.value`
* `cloudflare.r2.response.checksum.type`
* `cloudflare.r2.response.storage_class`
* `cloudflare.r2.response.ssec_key`
* `cloudflare.r2.response.content_type`
* `cloudflare.r2.response.content_encoding`
* `cloudflare.r2.response.content_disposition`
* `cloudflare.r2.response.content_language`
* `cloudflare.r2.response.cache_control`
* `cloudflare.r2.response.cache_expiry`
* `cloudflare.r2.response.custom_metadata`

---

### [Durable Object API](https://developers.cloudflare.com/durable-objects/)

#### `durable_object_subrequest`

---

### [Durable Object Storage SQL API](https://developers.cloudflare.com/durable-objects/api/sqlite-storage-api)

The SQL API allow you to modify the SQLite database embedded within a Durable Object.

#### [durable\_object\_storage\_exec](https://developers.cloudflare.com/durable-objects/api/sqlite-storage-api/#exec)

* `db.system.name`
* `db.operation.name`
* `db.query.text`
* `cloudflare.durable_object.query.bindings`
* `cloudflare.durable_object.response.rows_read`
* `cloudflare.durable_object.response.rows_written`

#### [durable\_object\_storage\_getDatabaseSize](https://developers.cloudflare.com/durable-objects/api/sqlite-storage-api/#databasesize)

* `db.operation.name`
* `cloudflare.durable_object.response.db_size`

#### [durable\_object\_storage\_kv\_get](https://developers.cloudflare.com/durable-objects/api/sqlite-storage-api/#get)

* `cloudflare.durable_object.kv.query.keys`
* `cloudflare.durable_object.kv.query.keys.count`

#### [durable\_object\_storage\_kv\_put](https://developers.cloudflare.com/durable-objects/api/sqlite-storage-api/#put)

* `cloudflare.durable_object.kv.query.keys`
* `cloudflare.durable_object.kv.query.keys.count`

#### [durable\_object\_storage\_kv\_delete](https://developers.cloudflare.com/durable-objects/api/sqlite-storage-api/#delete)

* `cloudflare.durable_object.kv.query.keys`
* `cloudflare.durable_object.kv.query.keys.count`
* `cloudflare.durable_object.kv.response.deleted_count`

#### [durable\_object\_storage\_kv\_list](https://developers.cloudflare.com/durable-objects/api/sqlite-storage-api/#list)

* `cloudflare.durable_object.kv.query.start`
* `cloudflare.durable_object.kv.query.startAfter`
* `cloudflare.durable_object.kv.query.end`
* `cloudflare.durable_object.kv.query.prefix`
* `cloudflare.durable_object.kv.query.reverse`
* `cloudflare.durable_object.kv.query.limit`

---

### [Durable Object Storage KV API](https://developers.cloudflare.com/durable-objects/api/legacy-kv-storage-api)

The legacy KV-backed API allows you to modify embedded storage within a Durable Object.

#### [durable\_object\_storage\_get](https://developers.cloudflare.com/durable-objects/api/legacy-kv-storage-api/#do-kv-async-get)

#### [durable\_object\_storage\_put](https://developers.cloudflare.com/durable-objects/api/legacy-kv-storage-api/#do-kv-async-put)

#### [durable\_object\_storage\_delete](https://developers.cloudflare.com/durable-objects/api/legacy-kv-storage-api/#do-kv-async-delete)

#### [durable\_object\_storage\_list](https://developers.cloudflare.com/durable-objects/api/legacy-kv-storage-api/#do-kv-async-list)

#### [durable\_object\_storage\_deleteAll](https://developers.cloudflare.com/durable-objects/api/legacy-kv-storage-api/#deleteall)

---

### [Durable Object Storage Alarms API](https://developers.cloudflare.com/durable-objects/api/alarms/)

#### [durable\_object\_alarms\_getAlarm](https://developers.cloudflare.com/durable-objects/api/alarms/#getalarm)

#### [durable\_object\_alarms\_setAlarm](https://developers.cloudflare.com/durable-objects/api/alarms/#setalarm)

#### [durable\_object\_alarms\_deleteAlarm](https://developers.cloudflare.com/durable-objects/api/alarms/#deletealarm)

---

### [Images](https://developers.cloudflare.com/images/optimization/transformations/bindings/)

### [images\_output](https://developers.cloudflare.com/images/optimization/transformations/bindings/#output)

* `cloudflare.binding.type`
* `cloudflare.images.options.format`
* `cloudflare.images.options.quality`
* `cloudflare.images.options.background`
* `cloudflare.images.options.anim`
* `cloudflare.images.options.transforms`
* `cloudflare.images.error.code`

### [images\_info](https://developers.cloudflare.com/images/optimization/transformations/bindings/#info)

* `cloudflare.binding.type`
* `cloudflare.images.options.encoding`
* `cloudflare.images.result.format`
* `cloudflare.images.result.file_size`
* `cloudflare.images.result.width`
* `cloudflare.images.result.height`
* `cloudflare.images.error.code`

---

### [Email](https://developers.cloudflare.com/email-routing/)

#### [reply\_email](https://developers.cloudflare.com/email-routing/email-workers/reply-email-workers/)

#### [forward\_email](https://developers.cloudflare.com/email-routing/email-workers/runtime-api/)

#### [send\_email](https://developers.cloudflare.com/email-routing/email-workers/send-email-workers/)

---

### [Queues](https://developers.cloudflare.com/queues/)

#### [queue\_send](https://developers.cloudflare.com/queues/configuration/javascript-apis/#queue)

#### [queue\_sendBatch](https://developers.cloudflare.com/queues/configuration/javascript-apis/#queue)

---

### [Rate limiting](https://developers.cloudflare.com/workers/runtime-apis/bindings/rate-limit/)

#### [ratelimit\_run](https://developers.cloudflare.com/workers/runtime-apis/bindings/rate-limit/#best-practices)

---

```json
{"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"item":{"@id":"/directory/","name":"Directory"}},{"@type":"ListItem","position":2,"item":{"@id":"/workers/","name":"Workers"}},{"@type":"ListItem","position":3,"item":{"@id":"/workers/observability/","name":"Observability"}},{"@type":"ListItem","position":4,"item":{"@id":"/workers/observability/traces/","name":"Traces"}},{"@type":"ListItem","position":5,"item":{"@id":"/workers/observability/traces/spans-and-attributes/","name":"Spans and attributes"}}]}
```