# Semantic conventions for CLI (command line interface) programs **Status**: [Development][DocumentStatus] This document defines semantic conventions to apply when instrumenting CLI programs, both as a caller and as callee. This document is intended for short-lived programs that end their execution, i.e. not daemon or long running background tasks. ## Execution (callee) spans **Status:**  This span describes CLI (Command Line Interfaces) program execution from a callee perspective. **Span name** SHOULD be set to {process.executable.name}. Instrumentations that have additional context about executed commands MAY use a different low-cardinality span name format and SHOULD document it. **Span status** SHOULD be set to Error if {process.exit.code} is not 0. Refer to the [Recording Errors](/docs/general/recording-errors.md) document for details on how to record span status. **Span kind** SHOULD be `INTERNAL`. | Attribute | Type | Description | Examples | [Requirement Level](https://opentelemetry.io/docs/specs/semconv/general/attribute-requirement-level/) | Stability | |---|---|---|---|---|---| | [`process.executable.name`](/docs/registry/attributes/process.md) | string | The name of the process executable. On Linux based systems, this SHOULD be set to the base name of the target of `/proc/[pid]/exe`. On Windows, this SHOULD be set to the base name of `GetProcessImageFileNameW`. | `otelcol` | `Required` |  | | [`process.exit.code`](/docs/registry/attributes/process.md) | int | The exit code of the process. | `127` | `Required` |  | | [`process.pid`](/docs/registry/attributes/process.md) | int | Process identifier (PID). | `1234` | `Required` |  | | [`error.type`](/docs/registry/attributes/error.md) | string | Describes a class of error the operation ended with. [1] | `timeout`; `java.net.UnknownHostException`; `server_certificate_invalid`; `500` | `Conditionally Required` if and only if process.exit.code is not 0 |  | | [`process.command_args`](/docs/registry/attributes/process.md) | string[] | All the command arguments (including the command/executable itself) as received by the process. On Linux-based systems (and some other Unixoid systems supporting procfs), can be set according to the list of null-delimited strings extracted from `proc/[pid]/cmdline`. For libc-based executables, this would be the full argv vector passed to `main`. SHOULD NOT be collected by default unless there is sanitization that excludes sensitive data. | `["cmd/otecol", "--config=config.yaml"]` | `Recommended` |  | | [`process.executable.path`](/docs/registry/attributes/process.md) | string | The full path to the process executable. On Linux based systems, can be set to the target of `proc/[pid]/exe`. On Windows, can be set to the result of `GetProcessImageFileNameW`. | `/usr/bin/cmd/otelcol` | `Recommended` |  | **[1] `error.type`:** The `error.type` SHOULD be predictable, and SHOULD have low cardinality. When `error.type` is set to a type (e.g., an exception type), its canonical class name identifying the type within the artifact SHOULD be used. Instrumentations SHOULD document the list of errors they report. The cardinality of `error.type` within one instrumentation library SHOULD be low. Telemetry consumers that aggregate data from multiple instrumentation libraries and applications should be prepared for `error.type` to have high cardinality at query time when no additional filters are applied. If the operation has completed successfully, instrumentations SHOULD NOT set `error.type`. If a specific domain defines its own set of error identifiers (such as HTTP or gRPC status codes), it's RECOMMENDED to: - Use a domain-specific attribute - Set `error.type` to capture all errors, regardless of whether they are defined within the domain-specific set or not. --- `error.type` has the following list of well-known values. If one of them applies, then the respective value MUST be used; otherwise, a custom value MAY be used. | Value | Description | Stability | |---|---|---| | `_OTHER` | A fallback error value to be used when the instrumentation doesn't define a custom value. |  | ## Client (caller) spans **Status:**  This span describes CLI (Command Line Interfaces) program execution from a caller perspective. **Span name** SHOULD be set to {process.executable.name}. Instrumentations that have additional context about executed commands MAY use a different low-cardinality span name format and SHOULD document it. **Span status** SHOULD be set to Error if {process.exit.code} is not 0. Refer to the [Recording Errors](/docs/general/recording-errors.md) document for details on how to record span status. **Span kind** SHOULD be `CLIENT`. | Attribute | Type | Description | Examples | [Requirement Level](https://opentelemetry.io/docs/specs/semconv/general/attribute-requirement-level/) | Stability | |---|---|---|---|---|---| | [`process.executable.name`](/docs/registry/attributes/process.md) | string | The name of the process executable. On Linux based systems, this SHOULD be set to the base name of the target of `/proc/[pid]/exe`. On Windows, this SHOULD be set to the base name of `GetProcessImageFileNameW`. | `otelcol` | `Required` |  | | [`process.exit.code`](/docs/registry/attributes/process.md) | int | The exit code of the process. | `127` | `Required` |  | | [`process.pid`](/docs/registry/attributes/process.md) | int | Process identifier (PID). | `1234` | `Required` |  | | [`error.type`](/docs/registry/attributes/error.md) | string | Describes a class of error the operation ended with. [1] | `timeout`; `java.net.UnknownHostException`; `server_certificate_invalid`; `500` | `Conditionally Required` if and only if process.exit.code is not 0 |  | | [`process.command_args`](/docs/registry/attributes/process.md) | string[] | All the command arguments (including the command/executable itself) as received by the process. On Linux-based systems (and some other Unixoid systems supporting procfs), can be set according to the list of null-delimited strings extracted from `proc/[pid]/cmdline`. For libc-based executables, this would be the full argv vector passed to `main`. SHOULD NOT be collected by default unless there is sanitization that excludes sensitive data. | `["cmd/otecol", "--config=config.yaml"]` | `Recommended` |  | | [`process.executable.path`](/docs/registry/attributes/process.md) | string | The full path to the process executable. On Linux based systems, can be set to the target of `proc/[pid]/exe`. On Windows, can be set to the result of `GetProcessImageFileNameW`. | `/usr/bin/cmd/otelcol` | `Recommended` |  | **[1] `error.type`:** The `error.type` SHOULD be predictable, and SHOULD have low cardinality. When `error.type` is set to a type (e.g., an exception type), its canonical class name identifying the type within the artifact SHOULD be used. Instrumentations SHOULD document the list of errors they report. The cardinality of `error.type` within one instrumentation library SHOULD be low. Telemetry consumers that aggregate data from multiple instrumentation libraries and applications should be prepared for `error.type` to have high cardinality at query time when no additional filters are applied. If the operation has completed successfully, instrumentations SHOULD NOT set `error.type`. If a specific domain defines its own set of error identifiers (such as HTTP or gRPC status codes), it's RECOMMENDED to: - Use a domain-specific attribute - Set `error.type` to capture all errors, regardless of whether they are defined within the domain-specific set or not. --- `error.type` has the following list of well-known values. If one of them applies, then the respective value MUST be used; otherwise, a custom value MAY be used. | Value | Description | Stability | |---|---|---| | `_OTHER` | A fallback error value to be used when the instrumentation doesn't define a custom value. |  | [DocumentStatus]: https://opentelemetry.io/docs/specs/otel/document-status