# Workspace Evidence v3 contract

This is the canonical public contract for the optional `evidence` object in a schema-v3
workspace descriptor. Evidence is optional: a valid v3 descriptor without it remains operational.
When present, `evidence` is strict: it contains `source` and a defaulted strict `policy`; every
source variant and the policy reject unknown keys.

## Filesystem source

A filesystem source uses the exact URI `workspace-content/<workspace.id>/evidence`. `patterns` is
a nonempty list of unique, normalized relative POSIX globs. Its defaults are
`patterns: ["**/*.md"]` and `max_bytes: 10485760`.

### Example: filesystem

```yaml
evidence:
  source:
    type: filesystem
    uri: workspace-content/example/evidence
    patterns:
      - "**/*.md"
    max_bytes: 10485760
  policy:
    max_chunk_chars: 4000
    retain_published_generations: 3
```

Safe: `workspace-content/example/evidence`. Unsafe filesystem identities include `/srv/evidence`,
`workspace-content/another/evidence`, and `workspace-content/example/../another/evidence` because
absolute, cross-namespace, and traversal paths are not canonical.

## HTTP source

`uris` is a nonempty, unique list of canonical HTTP or HTTPS provenance identities. Each URI must
have no whitespace, control character, backslash, userinfo, query, or fragment. Public mode uses
`authentication: none`; signed mode uses `authentication: signed_urls_file`. Defaults are
`authentication: none`, `connect_timeout_ms: 5000`, `read_timeout_ms: 30000`,
`max_bytes: 10485760`, `max_redirects: 5`, `allow_private_hosts: false`, and
`max_cache_bytes: 67108864`. Public HTTP (`authentication: none`) uses the declared query-free
URIs directly and requires no Evidence credential file. Signed HTTP uses the installation file
contract below and preserves a mandatory one-to-one provenance mapping in declared-URI order.

### Example: http

```yaml
evidence:
  source:
    type: http
    uris:
      - https://evidence.example.invalid/report.md
    authentication: signed_urls_file
    connect_timeout_ms: 5000
    read_timeout_ms: 30000
    max_bytes: 10485760
    max_redirects: 5
    allow_private_hosts: false
    max_cache_bytes: 67108864
  policy:
    max_chunk_chars: 4000
    retain_published_generations: 3
```

The shown provenance URI is safe and query-free. An HTTP fragment identity such as
`https://evidence.example.invalid/report.md#section` is unsafe. Query-bearing and userinfo-bearing
HTTP identities are rejected; public documentation must not spell or publish a signed transport
URL.

## S3 source

`uri` is a canonical `s3://` identity with a valid bucket and no port, userinfo, query, or fragment.
`endpoint_url`, when present, is an origin-only HTTP(S) URL; `region`, when present, is nonblank.
Defaults are `credentials: ambient`, `trusted_endpoint: false`, `allow_private_endpoint: false`,
`allow_insecure_endpoint: false`, `max_bytes: 10485760`, `max_objects: 10000`, `max_pages: 100`,
and `page_size: 1000` (and page size cannot exceed 1000). A custom endpoint requires
`trusted_endpoint: true`; an HTTP endpoint additionally requires `allow_insecure_endpoint: true`.
Endpoint-policy flags cannot be enabled without `endpoint_url`. Ambient S3
(`credentials: ambient`) uses the runtime provider chain and requires no Evidence credential file.
Static mode uses `credentials: static_files`, requires access-key and secret-key files together,
and permits an optional session-token file.

### Example: s3

```yaml
evidence:
  source:
    type: s3
    uri: s3://example-evidence/curated/
    credentials: static_files
    trusted_endpoint: false
    allow_private_endpoint: false
    allow_insecure_endpoint: false
    max_bytes: 10485760
    max_objects: 10000
    max_pages: 100
    page_size: 1000
  policy:
    max_chunk_chars: 4000
    retain_published_generations: 3
```

Safe: `s3://example-evidence/curated/`. Unsafe identities include
`s3://Invalid_Bucket/evidence` and `s3://example-evidence/evidence#section`. S3 userinfo and query
identities are rejected in prose and implementation; no credential-bearing example is published.

## Policy and numeric domains

The strict policy defaults to `max_chunk_chars: 4000` and
`retain_published_generations: 3`. Filesystem `max_bytes`; HTTP `connect_timeout_ms`,
`read_timeout_ms`, `max_bytes`, and `max_cache_bytes`; S3 `max_bytes`, `max_objects`, `max_pages`,
and `page_size`; and both policy values must be positive safe integers from 1 through
9007199254740991. HTTP `max_redirects` must be a nonnegative safe integer from 0 through
9007199254740991. S3 `page_size` has the stricter maximum of 1000.

## Installation files

The namespace is the workspace ID uppercased with every `-` changed to `_`. All Evidence variables
hold file paths, never credential or signed-URL values.

| Mode | Variable | File contract |
| --- | --- | --- |
| Signed HTTP | `THT_WS_<NAMESPACE>_EVIDENCE_SIGNED_URLS_FILE` | Required for `signed_urls_file`; at most 1048576 bytes; nonempty UTF-8 JSON string array in declared-URI order; query-stripped identities must match `uris` one-to-one. |
| Static S3 pair | `THT_WS_<NAMESPACE>_EVIDENCE_ACCESS_KEY_FILE` and `THT_WS_<NAMESPACE>_EVIDENCE_SECRET_KEY_FILE` | Required together for `static_files`; each file is at most 65536 bytes. |
| Static S3 session | `THT_WS_<NAMESPACE>_EVIDENCE_SESSION_TOKEN_FILE` | Optional, valid only with the required access/secret pair, and at most 65536 bytes. |

Every variable is an absolute path to a readable regular file whose resolved target is strictly below one of the roots configured by `THT_WORKSPACE_SECRET_ROOTS`. Scalar S3 files are nonempty
UTF-8 tokens without whitespace or NUL. Public docs, exports, and rendered YAML never expose file contents. `changeme`, `replace-me`, `YOUR_SECRET`, `<secret>`, access-key-looking strings, and any
credential-bearing or query-bearing URI are forbidden as public placeholder values.

## One shared registry repository

All workspace namespaces live in one Git repository:

```text
registry.git/
├── workspaces/
│   ├── example.yaml
│   └── another.yaml
├── workspace-content/
│   ├── example/evidence/...
│   └── another/evidence/...
└── workspace-docs/
    ├── example/{contract.env.example,README.md}
    └── another/{contract.env.example,README.md}
```

Curators change only `workspace-content/<id>/evidence/**` through a normal clone. The API publishes
only `workspaces/<id>.yaml` and
`workspace-docs/<id>/{contract.env.example,README.md}`. It never writes Evidence source bytes.

## Registry revision and phase ownership

| Relationship | Contract |
| --- | --- |
| Revision identity | The descriptor blob and filesystem Evidence root tree are checked at the same 40-hex Git commit. |
| Content-only revision | An Evidence-only commit changes authoritative `revision.commit` even when the descriptor blob is unchanged. |
| Browser | Create and edit flows preserve and show a read-only Evidence summary. |
| Export | Export remains exactly manifest, descriptor, contract, and README; it excludes Evidence bytes. |
| P1 | Validates the lexical URI and proves the declared filesystem root object is a Git tree at that same commit; it does not recursively inspect nested symlinks. |
| P6 | Owns commit-addressed materialization, realpath and recursive containment, nested-symlink checks, and race checks. |

P1 performs no acquisition, extraction, preprocessing/indexing, embeddings, Qdrant writes, `ACTIVE` publication, retention, or GC.

## Operator validation

After the runtime configuration is rendered or acquired, validate it with the exact per-command
option ordering:

```sh
tht config check -c <path>
```

Stop after validation. P2/P6 later owns preprocessing and materialization.

## Acceptance states

These gates are independent and are not implied by this documentation contract.

automated integration: PENDING
manual acceptance: PENDING