diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 703fed0..1a2f125 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -15,8 +15,7 @@ cd rigging
 make ci
 
 # Or run individual checks
-make test
-make test-race
+make test   # race-enabled test suite
 make fmt
 ```
 
@@ -41,7 +40,7 @@ make fmt
 
 ### Testing Requirements
 - All exported functions must have tests
-- Aim for >80% coverage
+- Keep coverage healthy; the current `make ci` gate fails below 70% total coverage
 - Use table-driven tests
 - Test error paths, not just happy paths
 
@@ -124,8 +123,8 @@ We reject:
 
 **Using Make (recommended):**
 ```bash
-make ci       # Run all CI checks (fmt, vet, test, lint)
-make test     # Run tests
+make ci       # Run all CI checks (fmt, vet, test, lint, coverage gate)
+make test     # Run race-enabled tests
 make fmt      # Format code
 make vet      # Run go vet
 make lint     # Run golangci-lint
diff --git a/docs/api-reference.md b/docs/api-reference.md
index d7aceb9..407973a 100644
--- a/docs/api-reference.md
+++ b/docs/api-reference.md
@@ -351,7 +351,7 @@ Configure binding and validation with the `conf` tag:
 | Tag | Description | Example |
 |-----|-------------|---------|
 | `required` | Field must have a value | `conf:"required"` |
-| `env:VAR` | Bind from an explicit env-style key path (normalized with `__` -> `.` and lowercased) | `conf:"env:APP__DATABASE__HOST"` |
+| `env:VAR` | Bind from an explicit env-style key path (normalized with `__` -> `.` and lowercased) after any `sourceenv.Options.Prefix` stripping | `conf:"env:DATABASE__HOST"` |
 | `default:X` | Default value if not provided | `conf:"default:8080"` |
 | `min:N` | Minimum value (numeric) or length (string) | `conf:"min:1024"` |
 | `max:N` | Maximum value (numeric) or length (string) | `conf:"max:65535"` |
@@ -373,7 +373,7 @@ type Config struct {
 **Tag precedence:**
 
 - `name:` overrides all key derivation (ignores `prefix:` and field name)
-- `env:` is used when `name:` is not set
+- `env:` is used when `name:` is not set; it matches the env-style key after any source prefix stripping
 - otherwise keys are derived from field names (snake_case), with parent `prefix:` for nested structs
 - env-style normalization converts `__` to `.` and preserves single `_`
 
diff --git a/docs/configuration-sources.md b/docs/configuration-sources.md
index d4b94b0..406eaa1 100644
--- a/docs/configuration-sources.md
+++ b/docs/configuration-sources.md
@@ -150,11 +150,13 @@ Important:
 - File source flattens nested objects but does not rewrite separators.
 - File source can optionally adapt flattened keys via `SnakeCaseKeys` and `KeyPrefix` in `sourcefile.Options`.
 - Rigging lowercases keys during loader merge for consistent matching across sources.
-- If your file keys are snake_case, use `name:` tags to match them.
+- Derived field keys are already snake_case, so `MaxConnections` matches `max_connections` without tags.
+- Use `name:` only when the source key path differs from the derived path, or use `SnakeCaseKeys` / `KeyPrefix` to adapt file keys at the source boundary.
 
 ```go
 type Config struct {
-    MaxConnections int `conf:"name:max_connections"`
+    MaxConnections int           // matches max_connections
+    LegacyPort     int `conf:"name:service.port"`
 }
 ```
 
diff --git a/docs/patterns.md b/docs/patterns.md
index b3df6c5..3484288 100644
--- a/docs/patterns.md
+++ b/docs/patterns.md
@@ -39,11 +39,12 @@ type Config struct {
 }
 ```
 
-If your source keys use snake_case or custom paths, map explicitly:
+Derived keys already use snake_case.
+Use `name:` when a source key path differs from the derived path:
 
 ```go
 type Config struct {
-    MaxConnections int `conf:"name:max_connections"`
+    MaxConnections int    // matches max_connections
     APIKey         string `conf:"name:api.key"`
 }
 ```
@@ -53,11 +54,12 @@ This is useful during migrations or when a legacy env variable name must be pres
 
 ```go
 type Config struct {
-    DatabaseHost string `conf:"env:APP__DATABASE__HOST,required"`
+    DatabaseHost string `conf:"env:DATABASE__HOST,required"`
 }
 ```
 
 `env:` normalizes env-style syntax (`__` -> `.`, lowercased) before matching.
+When `sourceenv` is configured with `Prefix: "APP_"`, `conf:"env:DATABASE__HOST"` matches `APP_DATABASE__HOST`.
 Prefer `name:` for general cross-source key mapping; use `env:` when the intent is specifically env-key compatibility.
 
 ## 4. Normalize Typed Values Before Validation
diff --git a/docs/quick-start.md b/docs/quick-start.md
index 208ec19..6b9d88b 100644
--- a/docs/quick-start.md
+++ b/docs/quick-start.md
@@ -116,15 +116,18 @@ File source behavior:
 - keys are flattened from file structure and lowercased
 - separators are not rewritten (for example, `max_connections` stays `max_connections`)
 
-If your file keys are snake_case, map explicitly:
+Derived field keys are already snake_case, so `MaxConnections` matches `max_connections` without extra tags.
+Use `name:` only when the source key path differs, or adapt file keys at the source boundary with `sourcefile.Options{SnakeCaseKeys: true}` / `KeyPrefix`.
 
 ```go
 type Config struct {
-    MaxConnections int `conf:"name:max_connections"`
+    MaxConnections int // matches max_connections
+    LegacyPort     int `conf:"name:service.port"`
 }
 ```
 
-If you need to bind a field to a specific environment-style key path, use `env:` (for example, `conf:"env:APP__DATABASE__HOST"`).
+If you need to bind a field to a specific environment-style key path, use `env:`.
+The tag matches the normalized key after any `sourceenv.Options.Prefix` stripping, so with `Prefix: "APP_"`, `APP_DATABASE__HOST` maps via `conf:"env:DATABASE__HOST"`.
 
 ## 7. Fail-Fast Validation
 
diff --git a/examples/README.md b/examples/README.md
index 3b3f089..eb76157 100644
--- a/examples/README.md
+++ b/examples/README.md
@@ -5,7 +5,7 @@ Use this page to quickly find the right example format.
 ## Runnable Examples
 
 - [basic](basic/) - End-to-end app config loading with file + env layering, validation, provenance, and redaction.
-- [transformer](transformer/) - Typed `WithTransformer(...)` canonicalization before tag validation.
+- [transformer](transformer/) - Typed transform-stage canonicalization before tag validation, shown with `WithTransformerFunc(...)`.
 
 Run it from the repository root:
 
diff --git a/examples/basic/README.md b/examples/basic/README.md
index b229035..aca7981 100644
--- a/examples/basic/README.md
+++ b/examples/basic/README.md
@@ -20,11 +20,12 @@ go run main.go
 # Switch to production environment
 export APP_ENVIRONMENT=production
 export APP_DATABASE__HOST=prod-db.example.com
+export APP_DATABASE__SSL_MODE=require
 go run main.go
 
 # Enable feature flags
 export APP_FEATURES__ENABLE_METRICS=true
-export APP_FEATURES__RATELIMIT=5000
+export APP_FEATURES__RATE_LIMIT=5000
 go run main.go
 ```
 
diff --git a/examples/basic/config.yaml b/examples/basic/config.yaml
index ed31334..f9cc02c 100644
--- a/examples/basic/config.yaml
+++ b/examples/basic/config.yaml
@@ -9,16 +9,16 @@ database:
   name: myapp_staging
   user: app_user
   password: staging_password_123
-  maxconnections: 25
-  sslmode: require
-  connecttimeout: 10s
+  max_connections: 25
+  ssl_mode: require
+  connect_timeout: 10s
 
 server:
   host: 0.0.0.0
   port: 8080
-  readtimeout: 30s
-  writetimeout: 30s
-  shutdowntimeout: 10s
+  read_timeout: 30s
+  write_timeout: 30s
+  shutdown_timeout: 10s
 
 logging:
   level: info
@@ -26,6 +26,6 @@ logging:
   output: stdout
 
 features:
-  enablemetrics: true
-  enabletracing: false
-  ratelimit: 1000
+  enable_metrics: true
+  enable_tracing: false
+  rate_limit: 1000