diff --git a/README.md b/README.md
index 09a6d36..870c1a4 100644
--- a/README.md
+++ b/README.md
@@ -83,8 +83,8 @@ assert_eq!(result.instance.facts_for_predicate("Ancestor").len(), 3);
 ```bash
 cargo run -- repl
 cargo run -- gui
-cargo run -- script examples/scripts/ancestor.chase
-cargo run -- script examples/scripts/sql_join.chase
+cargo run -- script examples/scripts/ancestor.ech
+cargo run -- script examples/scripts/sql_join.ech
 ```
 
 #### REPL language
@@ -174,10 +174,10 @@ Current limits:
 
 Runnable SQL examples:
 
-- `examples/scripts/sql_basic.chase`
-- `examples/scripts/sql_join.chase`
-- `examples/scripts/sql_self_join.chase`
-- `examples/scripts/sql_order_by.chase`
+- `examples/scripts/sql_basic.ech`
+- `examples/scripts/sql_join.ech`
+- `examples/scripts/sql_self_join.ech`
+- `examples/scripts/sql_order_by.ech`
 
 ### Development
 
diff --git a/examples/geolog/README.md b/examples/geolog/README.md
index 36b7efc..efedd69 100644
--- a/examples/geolog/README.md
+++ b/examples/geolog/README.md
@@ -1,7 +1,7 @@
 # Geolog DSL Structure
 
 This directory contains example `.geolog` files that use a richer DSL than the
-minimal `.chase` script language in `examples/scripts/`.
+minimal `.ech` script language in `examples/scripts/`.
 
 These files are reference material and experiments. They are not currently
 wired into the `query-engine` binary, REPL, SQL parser, or planner pipeline.
@@ -488,7 +488,7 @@ So the safest summary is:
 - Geolog examples define theories, instances, and chase-oriented structure.
 - Querying appears to be external, REPL-driven, or still in design.
 - The only clearly implemented query syntax in this repo today is the minimal
-  `.chase` frontend query language.
+  `.ech` frontend query language.
 
 ## Best Example Files by Feature
 
diff --git a/examples/scripts/README.md b/examples/scripts/README.md
index 5015141..c355a22 100644
--- a/examples/scripts/README.md
+++ b/examples/scripts/README.md
@@ -3,16 +3,16 @@
 These scripts can be executed with:
 
 ```bash
-make script SCRIPT=examples/scripts/ancestor.chase
-cargo run -- script examples/scripts/ancestor.chase
+make script SCRIPT=examples/scripts/ancestor.ech
+cargo run -- script examples/scripts/ancestor.ech
 ```
 
 Available examples:
 
-- `ancestor.chase`: transitive closure over `Parent/2`
-- `employee_departments.chase`: existential rule that creates labeled nulls
-- `same_team.chase`: conjunctive query with a self-join
-- `sql_basic.chase`: named-column filtering in the SQL frontend
-- `sql_join.chase`: multi-table SQL join over predicate-backed tables
-- `sql_self_join.chase`: self-join with SQL table aliases
-- `sql_order_by.chase`: ordered SQL output with `ORDER BY`
+- `ancestor.ech`: transitive closure over `Parent/2`
+- `employee_departments.ech`: existential rule that creates labeled nulls
+- `same_team.ech`: conjunctive query with a self-join
+- `sql_basic.ech`: named-column filtering in the SQL frontend
+- `sql_join.ech`: multi-table SQL join over predicate-backed tables
+- `sql_self_join.ech`: self-join with SQL table aliases
+- `sql_order_by.ech`: ordered SQL output with `ORDER BY`
diff --git a/examples/scripts/ancestor.chase b/examples/scripts/ancestor.ech
similarity index 100%
rename from examples/scripts/ancestor.chase
rename to examples/scripts/ancestor.ech
diff --git a/examples/scripts/employee_departments.chase b/examples/scripts/employee_departments.ech
similarity index 100%
rename from examples/scripts/employee_departments.chase
rename to examples/scripts/employee_departments.ech
diff --git a/examples/scripts/same_team.chase b/examples/scripts/same_team.ech
similarity index 100%
rename from examples/scripts/same_team.chase
rename to examples/scripts/same_team.ech
diff --git a/examples/scripts/sql_basic.chase b/examples/scripts/sql_basic.ech
similarity index 100%
rename from examples/scripts/sql_basic.chase
rename to examples/scripts/sql_basic.ech
diff --git a/examples/scripts/sql_join.chase b/examples/scripts/sql_join.ech
similarity index 100%
rename from examples/scripts/sql_join.chase
rename to examples/scripts/sql_join.ech
diff --git a/examples/scripts/sql_order_by.chase b/examples/scripts/sql_order_by.ech
similarity index 100%
rename from examples/scripts/sql_order_by.chase
rename to examples/scripts/sql_order_by.ech
diff --git a/examples/scripts/sql_self_join.chase b/examples/scripts/sql_self_join.ech
similarity index 100%
rename from examples/scripts/sql_self_join.chase
rename to examples/scripts/sql_self_join.ech