Provenance attributes

Every render result carries four content-identity fields: name, variant, template_hash, and render_hash. The provenance-attributes helper formats them into a flat string→string attribute map under stable, library-owned prompting_press.prompt.* keys — suitable for direct use as telemetry span attributes.

One-call span attachment

Rust

use prompting_press::ProvenanceExt; // import the extension trait

let result = prompt.render(&vars, None, &GuardConfig::default(), false)?;

// Returns BTreeMap<String, String> — exactly 4 entries, deterministic order.
let attrs = result.provenance_attributes();

// Pass directly to any span API that accepts an iterable of (key, value) pairs.
// e.g. with opentelemetry:
// span.set_attributes(attrs.iter().map(|(k, v)| KeyValue::new(k.clone(), v.clone())));

Python

result = prompt.render(Vars, vars_instance)

# Returns dict[str, str] — exactly 4 entries.
attrs = result.provenance_attributes()

# Pass directly to any span API:
# span.set_attributes(attrs)

TypeScript

const result = p.render({ name: "Ada", count: 3 });

// Returns Record<string, string> — exactly 4 entries.
const attrs = result.provenanceAttributes();

// Pass directly to any span API:
// span.setAttributes(attrs);

The four library-owned keys

Key	Value
prompting_press.prompt.name	The prompt’s name field
prompting_press.prompt.variant	The resolved variant arm ("default" when no arm was selected)
prompting_press.prompt.template_hash	Lowercase-hex SHA256(resolved variant source)
prompting_press.prompt.render_hash	Lowercase-hex SHA256(rendered output)

The template_hash content-addresses the template source (unchanged by guard mode). The render_hash content-addresses the rendered output; when the guard is enabled the hash is over the delimited body, when disabled over the plain body — both deterministic. Both hashes are content identifiers, not content.

These keys are not OTel GenAI-convention keys (only gen_ai.prompt.name exists in that convention; gen_ai.prompt.variant is not a convention key). A consumer may remap onto their tracer’s own convention by reading the four fields directly.

What is not included

The map is an explicit allowlist — it will never include text (the rendered body), guard (the guard advisory text), output_model, prompt metadata, or any other field. This is deliberate: auto-logging rendered prompt content to telemetry is a data-exposure risk, and flattening opaque metadata bags risks unbounded span cardinality.

Custom keys

The helper is additive. The four provenance fields are always publicly readable on the result, so you can build a custom-keyed map without it:

Rust

use std::collections::BTreeMap;

let custom: BTreeMap<String, String> = [
    ("my.prompt.name".to_string(), result.name.clone()),
    ("my.prompt.variant".to_string(), result.variant.clone()),
    ("my.prompt.template_hash".to_string(), result.template_hash.clone()),
    ("my.prompt.render_hash".to_string(), result.render_hash.clone()),
].into_iter().collect();

Python

custom = {
    "my.prompt.name": result.name,
    "my.prompt.variant": result.variant,
    "my.prompt.template_hash": result.template_hash,
    "my.prompt.render_hash": result.render_hash,
}

TypeScript

const custom = {
    "my.prompt.name": result.name,
    "my.prompt.variant": result.variant,
    "my.prompt.template_hash": result.templateHash,
    "my.prompt.render_hash": result.renderHash,
};

No telemetry coupling

The library adds no telemetry or observability dependency — neither as a hard dependency nor an optional extra. The helper builds a plain string→string map from fields that already exist on the result; it is a pure projection with no I/O and no callbacks. The caller decides whether and how to record the map.

Rust: importing the extension trait

In Rust, result.provenance_attributes() requires importing the ProvenanceExt trait:

use prompting_press::ProvenanceExt;

Alternatively, use the free function form directly:

use prompting_press::provenance_attributes_of;

let attrs = provenance_attributes_of(
    &result.name,
    &result.variant,
    &result.template_hash,
    &result.render_hash,
);