Execution Evidence Gate

Gate ID: execution-evidence

Enforces that an artifact has signed execution evidence from a specific environment before promotion. Ensures artifacts are observed running (with sufficient trace quality) before advancing through the release pipeline.

How It Works

Checks if the target environment requires execution evidence (configurable per environment)
Reads execution evidence metadata from the policy context
If no evidence exists, applies the configured action (warn or block)
If evidence exists, validates trace quality (minimum hot symbols and unique call paths)
Returns pass, warn, or block result

Configuration

{
  "PolicyGates": {
    "ExecutionEvidence": {
      "Enabled": false,
      "MissingEvidenceAction": "Warn",
      "RequiredEnvironments": ["production"],
      "MinHotSymbolCount": 3,
      "MinUniqueCallPaths": 1
    }
  }
}

Options

Option	Type	Default	Description
`Enabled`	bool	`false`	Whether the gate is active (opt-in)
`MissingEvidenceAction`	enum	`Warn`	Action when evidence is missing: `Warn` or `Block`
`RequiredEnvironments`	string[]	`["production"]`	Environments that require execution evidence
`MinHotSymbolCount`	int	`3`	Minimum hot symbols for sufficient trace quality
`MinUniqueCallPaths`	int	`1`	Minimum unique call paths for sufficient trace quality

Context Metadata Keys

The gate reads the following keys from PolicyGateContext.Metadata:

Key	Type	Description
`has_execution_evidence`	`"true"/"false"`	Whether execution evidence exists
`execution_evidence_hot_symbol_count`	int string	Number of hot symbols in the evidence
`execution_evidence_unique_call_paths`	int string	Number of unique call paths

Example Gate Results

Pass (evidence meets quality):

Execution evidence meets quality thresholds (hot symbols: 42, call paths: 17)

Pass (environment not required):

Execution evidence not required for environment 'staging'

Warn (no evidence, warn mode):

No execution evidence found for this artifact (warn mode)

Fail (no evidence, block mode):

No execution evidence found for this artifact in required environment

Fail (insufficient quality):

Execution evidence trace quality is insufficient: hot symbols 1 < 3 or call paths 0 < 1

Integration

This gate consumes stella.ops/executionEvidence@v1 predicates generated by the Signals execution evidence pipeline. Evidence is populated in the policy context during release evaluation.

Typical flow:

Artifact runs in staging environment
Signals captures runtime trace via eBPF/ETW
ExecutionEvidenceBuilder generates signed predicate
Release promotion to production triggers policy evaluation
This gate verifies execution evidence exists from staging

docs/contracts/execution-evidence-v1.md — Predicate contract
docs/modules/policy/gates/beacon-rate-gate.md — Companion beacon rate gate

Last updated: 2026-02-19.