# Evidence Packet

> A directory holding captured evidence beside a manifest that binds its provenance, digests, and the exact scope of what it proves.

**Tier:** 3 · **Normative weight:** implements `TM-EVD-002`, `TM-EVD-003`,
`TM-EVD-007`
**Requires:** [Evidence Hygiene](/docs/truth-machine/kit/evidence-hygiene/)

## Problem it removes

A screenshot in a chat, a pasted terminal block, a file named `final2.xlsx`
— the claim survives but its provenance does not. Later no one can say
where the evidence came from, whether it was altered, or what it was ever
supposed to prove.

## Mechanism

One directory per capture, named for a stable packet id, holding the
captured files beside a `manifest.toml` that records: the id, kind, capture
date, source, the SHA-256 of every retained file (`TM-EVD-007`: detectable
substitution), and an auditability class. Source representation is
preserved where policy permits; where it cannot be, the manifest records
what was observed, by whom, and why the original is unavailable
(`TM-EVD-002`). The provenance fields — source, capture event, integrity
mechanism, transforming actors — are `TM-EVD-003` made into TOML keys.

The manifest's `authority` field is the discipline that pays: two clauses,
"supports X; does not prove Y." Writing the second clause is what keeps
evidence from quietly inflating into conclusions.

## Cost

Authoring: the schema exists; the first packet takes minutes. Per change:
one manifest per capture — digests are one command. Per session: none;
packets are read when a claim is questioned.

## Do not adopt when

Git already versions and reviews the material — evidence packets for
source-code truth duplicate commits. The pattern is for truth Git does not
govern.

## Evidence

Assessed in [kinra-corpus](/docs/truth-machine/implementations/kinra-corpus/)
and used by the reference instance's own history (frozen, per its
charter). The [flow](/docs/truth-machine/implementations/flow/) evidence
store applies the same semantics inside an application. Validated by
[`evidence.schema.json`](/docs/truth-machine/schemas/evidence.schema.json).

## Template

[`templates/evidence-packet/manifest.toml`](/docs/truth-machine/templates/evidence-packet/manifest.toml)

## Related patterns

[Change Packet](/docs/truth-machine/kit/change-packet/) is what cites the
packet; evidence that nothing will ever cite may not need packeting at all.