diff --git a/README.md b/README.md
index dd2d095..8dd2f0c 100644
--- a/README.md
+++ b/README.md
@@ -6,7 +6,7 @@ credentials, or make network requests.
 
 Promptkit owns catalog parsing, validation, runtime behavior, credential
 handling, and consumer documentation. This module owns the OpenRouter backend
-manifest and its maintained profile data. Consumers should use versions chosen
+definition and its maintained profile data. Consumers should use versions chosen
 by their Promptkit release rather than treating this module as a standalone
 runtime integration.
 
@@ -16,17 +16,25 @@ and documentation.
 
 ## Compatibility
 
-This compatibility policy applies to the `/v2` module. Catalog profiles track
+This compatibility policy applies to the `/v3` module. Catalog profiles track
 upstream availability and may be added, removed, renamed, or modified without
 deprecation or advance notice. Consumers that need a particular profile set
 should use the catalog version selected by their Promptkit release.
 
-Backend definitions, the exported Go API, and the catalog manifest schema do
+Backend definitions, the exported Go API, and the catalog asset format do
 not share that profile-data exception. Their compatibility follows the normal
-semantic-versioning rules. Published v1 releases retain their historical
-contract; this README does not retroactively alter it.
+semantic-versioning rules. Published v1 and `/v2` releases retain their historical
+contracts; this README does not retroactively alter them.
 
-Catalog releases use dated versions in the form `v2.YYYYMMDD.N`. The date
+The `/v3` module replaces the `/v2` manifest and flat profile documents with
+ordinary keyed ConfigKit inputs: `catalog/backend.yml` defines
+`backends.openrouter`, and each file under `catalog/profiles/` defines one
+literal ID beneath `profiles`. Profile inheritance uses `extends` instead of
+`base_profile`. This asset-format change is incompatible with `/v2` consumers;
+they should remain on a published `/v2` version. The exported `FS` and `Root`
+remain the asset access surface.
+
+Catalog releases use dated versions in the form `v3.YYYYMMDD.N`. The date
 identifies when the catalog snapshot was published in UTC; it does not certify
 that a provider currently offers a model or endpoint named by the data.
 
diff --git a/catalog/backend.json b/catalog/backend.json
deleted file mode 100644
index 837cb7a..0000000
--- a/catalog/backend.json
+++ /dev/null
@@ -1,9 +0,0 @@
-{
-  "schema_version": 1,
-  "id": "openrouter",
-  "endpoint": "https://openrouter.ai/api/v1",
-  "api_key_env": "OPENROUTER_API_KEY",
-  "concurrency_limit": 16,
-  "queue_capacity": 1024,
-  "extra_params": null
-}
diff --git a/catalog/backend.yml b/catalog/backend.yml
new file mode 100644
index 0000000..b4ff7e3
--- /dev/null
+++ b/catalog/backend.yml
@@ -0,0 +1,6 @@
+backends:
+  openrouter:
+    endpoint: https://openrouter.ai/api/v1
+    api_key_env: OPENROUTER_API_KEY
+    concurrency_limit: 16
+    queue_capacity: 1024
diff --git a/catalog/profiles/aion-labs/aion-2.yml b/catalog/profiles/aion-labs/aion-2.yml
index a22cd8f..13d88b2 100644
--- a/catalog/profiles/aion-labs/aion-2.yml
+++ b/catalog/profiles/aion-labs/aion-2.yml
@@ -1,8 +1,9 @@
-id: aion-2
-backend: openrouter
-model: aion-labs/aion-2.0
-temperature: 0.72
-reasoning_effort: high
-top_p: 0.95
-timeout_seconds: 180
-service_tier: flex
+profiles:
+  aion-2:
+    backend: openrouter
+    model: aion-labs/aion-2.0
+    temperature: 0.72
+    reasoning_effort: high
+    top_p: 0.95
+    timeout_seconds: 180
+    service_tier: flex
diff --git a/catalog/profiles/aion-labs/aion-3-0-mini.yml b/catalog/profiles/aion-labs/aion-3-0-mini.yml
index 17b1f5b..268b3f0 100644
--- a/catalog/profiles/aion-labs/aion-3-0-mini.yml
+++ b/catalog/profiles/aion-labs/aion-3-0-mini.yml
@@ -1,4 +1,5 @@
-id: aion-3-0-mini
-backend: openrouter
-model: "aion-labs/aion-3.0-mini"
-service_tier: flex
+profiles:
+  aion-3-0-mini:
+    backend: openrouter
+    model: "aion-labs/aion-3.0-mini"
+    service_tier: flex
diff --git a/catalog/profiles/aion-labs/aion-3-0.yml b/catalog/profiles/aion-labs/aion-3-0.yml
index 8cd3f7c..03756b4 100644
--- a/catalog/profiles/aion-labs/aion-3-0.yml
+++ b/catalog/profiles/aion-labs/aion-3-0.yml
@@ -1,4 +1,5 @@
-id: aion-3-0
-backend: openrouter
-model: "aion-labs/aion-3.0"
-service_tier: flex
+profiles:
+  aion-3-0:
+    backend: openrouter
+    model: "aion-labs/aion-3.0"
+    service_tier: flex
diff --git a/catalog/profiles/anthropic/claude-fable-latest.yml b/catalog/profiles/anthropic/claude-fable-latest.yml
index 0affde6..5168630 100644
--- a/catalog/profiles/anthropic/claude-fable-latest.yml
+++ b/catalog/profiles/anthropic/claude-fable-latest.yml
@@ -1,6 +1,7 @@
-id: claude-fable-latest
-backend: openrouter
-model: "~anthropic/claude-fable-latest"
-reasoning_effort: high
-timeout_seconds: 600
-service_tier: flex
+profiles:
+  claude-fable-latest:
+    backend: openrouter
+    model: "~anthropic/claude-fable-latest"
+    reasoning_effort: high
+    timeout_seconds: 600
+    service_tier: flex
diff --git a/catalog/profiles/anthropic/claude-haiku-latest.yml b/catalog/profiles/anthropic/claude-haiku-latest.yml
index e5ada35..79110c5 100644
--- a/catalog/profiles/anthropic/claude-haiku-latest.yml
+++ b/catalog/profiles/anthropic/claude-haiku-latest.yml
@@ -1,6 +1,7 @@
-id: claude-haiku-latest
-backend: openrouter
-model: "~anthropic/claude-haiku-latest"
-reasoning_effort: medium
-timeout_seconds: 240
-service_tier: flex
+profiles:
+  claude-haiku-latest:
+    backend: openrouter
+    model: "~anthropic/claude-haiku-latest"
+    reasoning_effort: medium
+    timeout_seconds: 240
+    service_tier: flex
diff --git a/catalog/profiles/anthropic/claude-opus-latest.yml b/catalog/profiles/anthropic/claude-opus-latest.yml
index 6d628ac..512ee2a 100644
--- a/catalog/profiles/anthropic/claude-opus-latest.yml
+++ b/catalog/profiles/anthropic/claude-opus-latest.yml
@@ -1,6 +1,7 @@
-id: claude-opus-latest
-backend: openrouter
-model: "~anthropic/claude-opus-latest"
-reasoning_effort: high
-timeout_seconds: 240
-service_tier: flex
+profiles:
+  claude-opus-latest:
+    backend: openrouter
+    model: "~anthropic/claude-opus-latest"
+    reasoning_effort: high
+    timeout_seconds: 240
+    service_tier: flex
diff --git a/catalog/profiles/anthropic/claude-sonnet-latest.yml b/catalog/profiles/anthropic/claude-sonnet-latest.yml
index adce8d6..373cb11 100644
--- a/catalog/profiles/anthropic/claude-sonnet-latest.yml
+++ b/catalog/profiles/anthropic/claude-sonnet-latest.yml
@@ -1,6 +1,7 @@
-id: claude-sonnet-latest
-backend: openrouter
-model: "~anthropic/claude-sonnet-latest"
-reasoning_effort: high
-timeout_seconds: 240
-service_tier: flex
+profiles:
+  claude-sonnet-latest:
+    backend: openrouter
+    model: "~anthropic/claude-sonnet-latest"
+    reasoning_effort: high
+    timeout_seconds: 240
+    service_tier: flex
diff --git a/catalog/profiles/deepseek/deepseek-flash-latest.yml b/catalog/profiles/deepseek/deepseek-flash-latest.yml
index 4e176e9..b76cc53 100644
--- a/catalog/profiles/deepseek/deepseek-flash-latest.yml
+++ b/catalog/profiles/deepseek/deepseek-flash-latest.yml
@@ -1,4 +1,5 @@
-id: deepseek-flash-latest
-backend: openrouter
-model: "~deepseek/deepseek-flash-latest"
-service_tier: flex
+profiles:
+  deepseek-flash-latest:
+    backend: openrouter
+    model: "~deepseek/deepseek-flash-latest"
+    service_tier: flex
diff --git a/catalog/profiles/deepseek/deepseek-pro-latest.yml b/catalog/profiles/deepseek/deepseek-pro-latest.yml
index a36858b..07d9350 100644
--- a/catalog/profiles/deepseek/deepseek-pro-latest.yml
+++ b/catalog/profiles/deepseek/deepseek-pro-latest.yml
@@ -1,4 +1,5 @@
-id: deepseek-pro-latest
-backend: openrouter
-model: "~deepseek/deepseek-pro-latest"
-service_tier: flex
+profiles:
+  deepseek-pro-latest:
+    backend: openrouter
+    model: "~deepseek/deepseek-pro-latest"
+    service_tier: flex
diff --git a/catalog/profiles/google/gemini-3-5-flash-lite.yml b/catalog/profiles/google/gemini-3-5-flash-lite.yml
index 5758c9c..683365e 100644
--- a/catalog/profiles/google/gemini-3-5-flash-lite.yml
+++ b/catalog/profiles/google/gemini-3-5-flash-lite.yml
@@ -1,4 +1,5 @@
-id: gemini-3-5-flash-lite
-backend: openrouter
-model: "google/gemini-3.5-flash-lite"
-service_tier: flex
+profiles:
+  gemini-3-5-flash-lite:
+    backend: openrouter
+    model: "google/gemini-3.5-flash-lite"
+    service_tier: flex
diff --git a/catalog/profiles/google/gemini-3-5-flash.yml b/catalog/profiles/google/gemini-3-5-flash.yml
index b6c9430..24f53f1 100644
--- a/catalog/profiles/google/gemini-3-5-flash.yml
+++ b/catalog/profiles/google/gemini-3-5-flash.yml
@@ -1,4 +1,5 @@
-id: gemini-3-5-flash
-backend: openrouter
-model: "google/gemini-3.5-flash"
-service_tier: flex
+profiles:
+  gemini-3-5-flash:
+    backend: openrouter
+    model: "google/gemini-3.5-flash"
+    service_tier: flex
diff --git a/catalog/profiles/google/gemini-3-6-flash.yml b/catalog/profiles/google/gemini-3-6-flash.yml
index bafe035..94416a5 100644
--- a/catalog/profiles/google/gemini-3-6-flash.yml
+++ b/catalog/profiles/google/gemini-3-6-flash.yml
@@ -1,4 +1,5 @@
-id: gemini-3-6-flash
-backend: openrouter
-model: "google/gemini-3.6-flash"
-service_tier: flex
+profiles:
+  gemini-3-6-flash:
+    backend: openrouter
+    model: "google/gemini-3.6-flash"
+    service_tier: flex
diff --git a/catalog/profiles/google/gemini-3-7-flash.yml b/catalog/profiles/google/gemini-3-7-flash.yml
index 12eb212..a290701 100644
--- a/catalog/profiles/google/gemini-3-7-flash.yml
+++ b/catalog/profiles/google/gemini-3-7-flash.yml
@@ -1,4 +1,5 @@
-id: gemini-3-7-flash
-backend: openrouter
-model: "google/gemini-3.7-flash"
-service_tier: flex
+profiles:
+  gemini-3-7-flash:
+    backend: openrouter
+    model: "google/gemini-3.7-flash"
+    service_tier: flex
diff --git a/catalog/profiles/google/gemini-3-8-flash.yml b/catalog/profiles/google/gemini-3-8-flash.yml
index 7fa76b4..9732ac5 100644
--- a/catalog/profiles/google/gemini-3-8-flash.yml
+++ b/catalog/profiles/google/gemini-3-8-flash.yml
@@ -1,4 +1,5 @@
-id: gemini-3-8-flash
-backend: openrouter
-model: "google/gemini-3.8-flash"
-service_tier: flex
+profiles:
+  gemini-3-8-flash:
+    backend: openrouter
+    model: "google/gemini-3.8-flash"
+    service_tier: flex
diff --git a/catalog/profiles/google/gemini-3-flash-lite.yml b/catalog/profiles/google/gemini-3-flash-lite.yml
index 4ff439b..004e215 100644
--- a/catalog/profiles/google/gemini-3-flash-lite.yml
+++ b/catalog/profiles/google/gemini-3-flash-lite.yml
@@ -1,8 +1,9 @@
-id: gemini-3-flash-lite
-backend: openrouter
-model: "google/gemini-3.1-flash-lite"
-#temperature: 0.15
-reasoning_effort: high
-#top_p: 0.98
-timeout_seconds: 240
-service_tier: flex
+profiles:
+  gemini-3-flash-lite:
+    backend: openrouter
+    model: "google/gemini-3.1-flash-lite"
+    #temperature: 0.15
+    reasoning_effort: high
+    #top_p: 0.98
+    timeout_seconds: 240
+    service_tier: flex
diff --git a/catalog/profiles/google/gemini-flash-latest.yml b/catalog/profiles/google/gemini-flash-latest.yml
index 89acd90..7339db5 100644
--- a/catalog/profiles/google/gemini-flash-latest.yml
+++ b/catalog/profiles/google/gemini-flash-latest.yml
@@ -1,8 +1,9 @@
-id: gemini-flash-latest
-backend: openrouter
-model: "~google/gemini-flash-latest"
-#temperature: 0.15
-reasoning_effort: high
-#top_p: 0.98
-timeout_seconds: 240
-service_tier: flex
+profiles:
+  gemini-flash-latest:
+    backend: openrouter
+    model: "~google/gemini-flash-latest"
+    #temperature: 0.15
+    reasoning_effort: high
+    #top_p: 0.98
+    timeout_seconds: 240
+    service_tier: flex
diff --git a/catalog/profiles/google/gemini-pro-latest.yml b/catalog/profiles/google/gemini-pro-latest.yml
index 2ce5303..f19e279 100644
--- a/catalog/profiles/google/gemini-pro-latest.yml
+++ b/catalog/profiles/google/gemini-pro-latest.yml
@@ -1,8 +1,9 @@
-id: gemini-pro-latest
-backend: openrouter
-model: "~google/gemini-pro-latest"
-#temperature: 0.15
-reasoning_effort: high
-#top_p: 0.98
-timeout_seconds: 240
-service_tier: flex
+profiles:
+  gemini-pro-latest:
+    backend: openrouter
+    model: "~google/gemini-pro-latest"
+    #temperature: 0.15
+    reasoning_effort: high
+    #top_p: 0.98
+    timeout_seconds: 240
+    service_tier: flex
diff --git a/catalog/profiles/google/gemma-4-31b.yml b/catalog/profiles/google/gemma-4-31b.yml
index 39c3529..a818b4f 100644
--- a/catalog/profiles/google/gemma-4-31b.yml
+++ b/catalog/profiles/google/gemma-4-31b.yml
@@ -1,8 +1,9 @@
-id: gemma-4-31b
-backend: openrouter
-model: google/gemma-4-31b-it:exacto
-temperature: 0.15
-reasoning_effort: high
-top_p: 0.98
-timeout_seconds: 240
-service_tier: flex
+profiles:
+  gemma-4-31b:
+    backend: openrouter
+    model: google/gemma-4-31b-it:exacto
+    temperature: 0.15
+    reasoning_effort: high
+    top_p: 0.98
+    timeout_seconds: 240
+    service_tier: flex
diff --git a/catalog/profiles/minimax/minimax-m2.yml b/catalog/profiles/minimax/minimax-m2.yml
index 385a181..eb15092 100644
--- a/catalog/profiles/minimax/minimax-m2.yml
+++ b/catalog/profiles/minimax/minimax-m2.yml
@@ -1,8 +1,9 @@
-id: minimax-m2
-backend: openrouter
-model: minimax/minimax-m2.5
-temperature: 0.5
-reasoning_effort: high
-top_p: 0.95
-timeout_seconds: 180
-service_tier: flex
+profiles:
+  minimax-m2:
+    backend: openrouter
+    model: minimax/minimax-m2.5
+    temperature: 0.5
+    reasoning_effort: high
+    top_p: 0.95
+    timeout_seconds: 180
+    service_tier: flex
diff --git a/catalog/profiles/minimax/minimax-m3.yml b/catalog/profiles/minimax/minimax-m3.yml
index c0c1bd0..e67d418 100644
--- a/catalog/profiles/minimax/minimax-m3.yml
+++ b/catalog/profiles/minimax/minimax-m3.yml
@@ -1,8 +1,9 @@
-id: minimax-m3
-backend: openrouter
-model: minimax/minimax-m3
-#temperature: 0.5
-reasoning_effort: high
-#top_p: 0.95
-timeout_seconds: 180
-service_tier: flex
+profiles:
+  minimax-m3:
+    backend: openrouter
+    model: minimax/minimax-m3
+    #temperature: 0.5
+    reasoning_effort: high
+    #top_p: 0.95
+    timeout_seconds: 180
+    service_tier: flex
diff --git a/catalog/profiles/mistral/mistral-large-2512.yml b/catalog/profiles/mistral/mistral-large-2512.yml
index c77c9d8..9abdd7a 100644
--- a/catalog/profiles/mistral/mistral-large-2512.yml
+++ b/catalog/profiles/mistral/mistral-large-2512.yml
@@ -1,6 +1,7 @@
-id: mistral-large-2512
-backend: openrouter
-model: mistralai/mistral-large-2512
-temperature: 0.15
-top_p: 0.98
-timeout_seconds: 180
+profiles:
+  mistral-large-2512:
+    backend: openrouter
+    model: mistralai/mistral-large-2512
+    temperature: 0.15
+    top_p: 0.98
+    timeout_seconds: 180
diff --git a/catalog/profiles/mistral/mistral-medium-3-5.yml b/catalog/profiles/mistral/mistral-medium-3-5.yml
index b5201ca..2f35c07 100644
--- a/catalog/profiles/mistral/mistral-medium-3-5.yml
+++ b/catalog/profiles/mistral/mistral-medium-3-5.yml
@@ -1,7 +1,8 @@
-id: mistral-medium-3-5
-backend: openrouter
-model: mistralai/mistral-medium-3-5
-temperature: 0.15
-reasoning_effort: high
-top_p: 0.98
-timeout_seconds: 180
+profiles:
+  mistral-medium-3-5:
+    backend: openrouter
+    model: mistralai/mistral-medium-3-5
+    temperature: 0.15
+    reasoning_effort: high
+    top_p: 0.98
+    timeout_seconds: 180
diff --git a/catalog/profiles/mistral/mistral-small-3.yml b/catalog/profiles/mistral/mistral-small-3.yml
index 7e01e55..f14360d 100644
--- a/catalog/profiles/mistral/mistral-small-3.yml
+++ b/catalog/profiles/mistral/mistral-small-3.yml
@@ -1,6 +1,7 @@
-id: mistral-small-3
-backend: openrouter
-model: mistralai/mistral-small-3.2-24b-instruct
-temperature: 0.05
-top_p: 1.0
-timeout_seconds: 180
+profiles:
+  mistral-small-3:
+    backend: openrouter
+    model: mistralai/mistral-small-3.2-24b-instruct
+    temperature: 0.05
+    top_p: 1.0
+    timeout_seconds: 180
diff --git a/catalog/profiles/mistral/mistral-small-4.yml b/catalog/profiles/mistral/mistral-small-4.yml
index 2d9b44c..7e5d66a 100644
--- a/catalog/profiles/mistral/mistral-small-4.yml
+++ b/catalog/profiles/mistral/mistral-small-4.yml
@@ -1,7 +1,8 @@
-id: mistral-small-4
-backend: openrouter
-model: mistralai/mistral-small-2603
-temperature: 0.1
-reasoning_effort: high
-top_p: 0.98
-timeout_seconds: 180
+profiles:
+  mistral-small-4:
+    backend: openrouter
+    model: mistralai/mistral-small-2603
+    temperature: 0.1
+    reasoning_effort: high
+    top_p: 0.98
+    timeout_seconds: 180
diff --git a/catalog/profiles/nvidia/nemotron-3-ultra.yml b/catalog/profiles/nvidia/nemotron-3-ultra.yml
index 90f84f3..4199712 100644
--- a/catalog/profiles/nvidia/nemotron-3-ultra.yml
+++ b/catalog/profiles/nvidia/nemotron-3-ultra.yml
@@ -1,6 +1,7 @@
-id: nemotron-3-ultra
-backend: openrouter
-model: nvidia/nemotron-3-ultra-550b-a55b
-reasoning_effort: high
-timeout_seconds: 180
-service_tier: flex
+profiles:
+  nemotron-3-ultra:
+    backend: openrouter
+    model: nvidia/nemotron-3-ultra-550b-a55b
+    reasoning_effort: high
+    timeout_seconds: 180
+    service_tier: flex
diff --git a/catalog/profiles/openai/gpt-5-6-luna.yml b/catalog/profiles/openai/gpt-5-6-luna.yml
index af0ff09..cac7c8e 100644
--- a/catalog/profiles/openai/gpt-5-6-luna.yml
+++ b/catalog/profiles/openai/gpt-5-6-luna.yml
@@ -1,4 +1,5 @@
-id: gpt-5-6-luna
-backend: openrouter
-model: "openai/gpt-5.6-luna"
-service_tier: flex
+profiles:
+  gpt-5-6-luna:
+    backend: openrouter
+    model: "openai/gpt-5.6-luna"
+    service_tier: flex
diff --git a/catalog/profiles/openai/gpt-5-6-sol.yml b/catalog/profiles/openai/gpt-5-6-sol.yml
index 177cbc2..daf78ba 100644
--- a/catalog/profiles/openai/gpt-5-6-sol.yml
+++ b/catalog/profiles/openai/gpt-5-6-sol.yml
@@ -1,4 +1,5 @@
-id: gpt-5-6-sol
-backend: openrouter
-model: "openai/gpt-5.6-sol"
-service_tier: flex
+profiles:
+  gpt-5-6-sol:
+    backend: openrouter
+    model: "openai/gpt-5.6-sol"
+    service_tier: flex
diff --git a/catalog/profiles/openai/gpt-5-6-terra.yml b/catalog/profiles/openai/gpt-5-6-terra.yml
index 637f2b7..db61eae 100644
--- a/catalog/profiles/openai/gpt-5-6-terra.yml
+++ b/catalog/profiles/openai/gpt-5-6-terra.yml
@@ -1,4 +1,5 @@
-id: gpt-5-6-terra
-backend: openrouter
-model: "openai/gpt-5.6-terra"
-service_tier: flex
+profiles:
+  gpt-5-6-terra:
+    backend: openrouter
+    model: "openai/gpt-5.6-terra"
+    service_tier: flex
diff --git a/catalog/profiles/openai/gpt-6-astra.yml b/catalog/profiles/openai/gpt-6-astra.yml
index 83cc939..96c027e 100644
--- a/catalog/profiles/openai/gpt-6-astra.yml
+++ b/catalog/profiles/openai/gpt-6-astra.yml
@@ -1,4 +1,5 @@
-id: gpt-6-astra
-backend: openrouter
-model: "openai/gpt-6-astra"
-service_tier: flex
+profiles:
+  gpt-6-astra:
+    backend: openrouter
+    model: "openai/gpt-6-astra"
+    service_tier: flex
diff --git a/catalog/profiles/openai/gpt-astra-latest.yml b/catalog/profiles/openai/gpt-astra-latest.yml
index 0ca7462..771c9d4 100644
--- a/catalog/profiles/openai/gpt-astra-latest.yml
+++ b/catalog/profiles/openai/gpt-astra-latest.yml
@@ -1,4 +1,5 @@
-id: gpt-astra-latest
-backend: openrouter
-model: "~openai/gpt-astra-latest"
-service_tier: flex
+profiles:
+  gpt-astra-latest:
+    backend: openrouter
+    model: "~openai/gpt-astra-latest"
+    service_tier: flex
diff --git a/catalog/profiles/openai/gpt-luna-latest.yml b/catalog/profiles/openai/gpt-luna-latest.yml
index ca59a84..db408dd 100644
--- a/catalog/profiles/openai/gpt-luna-latest.yml
+++ b/catalog/profiles/openai/gpt-luna-latest.yml
@@ -1,4 +1,5 @@
-id: gpt-luna-latest
-backend: openrouter
-model: "~openai/gpt-luna-latest"
-service_tier: flex
+profiles:
+  gpt-luna-latest:
+    backend: openrouter
+    model: "~openai/gpt-luna-latest"
+    service_tier: flex
diff --git a/catalog/profiles/openai/gpt-sol-latest.yml b/catalog/profiles/openai/gpt-sol-latest.yml
index 63af353..5ecf002 100644
--- a/catalog/profiles/openai/gpt-sol-latest.yml
+++ b/catalog/profiles/openai/gpt-sol-latest.yml
@@ -1,4 +1,5 @@
-id: gpt-sol-latest
-backend: openrouter
-model: "~openai/gpt-sol-latest"
-service_tier: flex
+profiles:
+  gpt-sol-latest:
+    backend: openrouter
+    model: "~openai/gpt-sol-latest"
+    service_tier: flex
diff --git a/catalog/profiles/openai/gpt-terra-latest.yml b/catalog/profiles/openai/gpt-terra-latest.yml
index 8b86ad0..b6c81aa 100644
--- a/catalog/profiles/openai/gpt-terra-latest.yml
+++ b/catalog/profiles/openai/gpt-terra-latest.yml
@@ -1,4 +1,5 @@
-id: gpt-terra-latest
-backend: openrouter
-model: "~openai/gpt-terra-latest"
-service_tier: flex
+profiles:
+  gpt-terra-latest:
+    backend: openrouter
+    model: "~openai/gpt-terra-latest"
+    service_tier: flex
diff --git a/catalog/profiles/x-ai/grok-latest.yml b/catalog/profiles/x-ai/grok-latest.yml
index 2e6e840..c6806ea 100644
--- a/catalog/profiles/x-ai/grok-latest.yml
+++ b/catalog/profiles/x-ai/grok-latest.yml
@@ -1,4 +1,5 @@
-id: grok-latest
-backend: openrouter
-model: "~x-ai/grok-latest"
-service_tier: flex
+profiles:
+  grok-latest:
+    backend: openrouter
+    model: "~x-ai/grok-latest"
+    service_tier: flex
diff --git a/catalog/profiles/z-ai/glm-flash-latest.yml b/catalog/profiles/z-ai/glm-flash-latest.yml
index 6ea13aa..c1977de 100644
--- a/catalog/profiles/z-ai/glm-flash-latest.yml
+++ b/catalog/profiles/z-ai/glm-flash-latest.yml
@@ -1,4 +1,5 @@
-id: glm-flash-latest
-backend: openrouter
-model: "~z-ai/glm-flash-latest"
-service_tier: flex
+profiles:
+  glm-flash-latest:
+    backend: openrouter
+    model: "~z-ai/glm-flash-latest"
+    service_tier: flex
diff --git a/catalog/profiles/z-ai/glm-latest.yml b/catalog/profiles/z-ai/glm-latest.yml
index bd5e227..5c58bcd 100644
--- a/catalog/profiles/z-ai/glm-latest.yml
+++ b/catalog/profiles/z-ai/glm-latest.yml
@@ -1,4 +1,5 @@
-id: glm-latest
-backend: openrouter
-model: "~z-ai/glm-latest"
-service_tier: flex
+profiles:
+  glm-latest:
+    backend: openrouter
+    model: "~z-ai/glm-latest"
+    service_tier: flex
diff --git a/catalog_test.go b/catalog_test.go
index 645b1d1..6d3b217 100644
--- a/catalog_test.go
+++ b/catalog_test.go
@@ -2,11 +2,11 @@ package openrouter
 
 import (
 	"bytes"
-	"encoding/json"
 	"errors"
 	"fmt"
 	"io"
 	"io/fs"
+	"path"
 	"strings"
 	"testing"
 
@@ -14,188 +14,145 @@ import (
 )
 
 func TestCatalogLayoutAndContents(t *testing.T) {
-	fsys := FS()
-	if fsys == nil {
+	assets := FS()
+	if assets == nil {
 		t.Fatal("FS returned nil")
 	}
-
-	manifestPath := Root + "/backend.json"
-	manifestData, err := fs.ReadFile(fsys, manifestPath)
+	backendPath := Root + "/backend.yml"
+	backendData, err := fs.ReadFile(assets, backendPath)
 	if err != nil {
-		t.Fatalf("read manifest: %v", err)
+		t.Fatalf("read backend: %v", err)
 	}
-	assertOpenRouterManifest(t, manifestData)
+	assertBackend(t, backendData)
 
 	profilesRoot := Root + "/profiles"
-	profileCount := 0
-	ids := map[string]string{}
-	err = fs.WalkDir(fsys, Root, func(path string, entry fs.DirEntry, walkErr error) error {
+	ids := make(map[string]string)
+	err = fs.WalkDir(assets, Root, func(assetPath string, entry fs.DirEntry, walkErr error) error {
 		if walkErr != nil {
 			return walkErr
 		}
-		if path == Root || path == profilesRoot || entry.IsDir() {
+		if assetPath == Root || assetPath == profilesRoot || entry.IsDir() {
 			return nil
 		}
-		if path == manifestPath {
+		if assetPath == backendPath {
 			if !entry.Type().IsRegular() {
-				return fmt.Errorf("manifest is not a regular file")
+				return fmt.Errorf("backend asset is not a regular file")
 			}
 			return nil
 		}
-		if !strings.HasPrefix(path, profilesRoot+"/") {
-			return fmt.Errorf("unexpected catalog entry %q", path)
+		if !strings.HasPrefix(assetPath, profilesRoot+"/") {
+			return fmt.Errorf("unexpected catalog entry %q", assetPath)
 		}
-		if !entry.Type().IsRegular() || !strings.HasSuffix(path, ".yml") {
-			return fmt.Errorf("profile asset %q is not a regular .yml file", path)
+		if !entry.Type().IsRegular() || !strings.HasSuffix(assetPath, ".yml") {
+			return fmt.Errorf("profile asset %q is not a regular .yml file", assetPath)
 		}
-
-		data, err := fs.ReadFile(fsys, path)
+		data, err := fs.ReadFile(assets, assetPath)
 		if err != nil {
 			return err
 		}
-		id := assertOpenRouterProfile(t, path, data)
+		id := assertProfile(t, assetPath, data)
 		if previous, found := ids[id]; found {
-			return fmt.Errorf("duplicate profile ID %q in %s and %s", id, previous, path)
+			return fmt.Errorf("duplicate profile ID %q in %s and %s", id, previous, assetPath)
 		}
-		ids[id] = path
-		profileCount++
+		ids[id] = assetPath
 		return nil
 	})
 	if err != nil {
 		t.Fatalf("validate catalog layout: %v", err)
 	}
-	if profileCount == 0 {
-		t.Fatal("catalog contains no profiles")
+	if len(ids) != 36 {
+		t.Fatalf("profile inventory changed: got %d, want 36", len(ids))
 	}
 }
 
-func assertOpenRouterManifest(t *testing.T, data []byte) {
+func assertBackend(t *testing.T, data []byte) {
 	t.Helper()
-
-	type manifest struct {
-		SchemaVersion    int             `json:"schema_version"`
-		ID               string          `json:"id"`
-		Endpoint         string          `json:"endpoint"`
-		APIKeyEnv        string          `json:"api_key_env"`
-		ConcurrencyLimit int             `json:"concurrency_limit"`
-		QueueCapacity    int             `json:"queue_capacity"`
-		ExtraParams      json.RawMessage `json:"extra_params"`
+	root := decodeMapping(t, "backend", data)
+	backends := requireSingleMapping(t, "backend", root, "backends")
+	if len(backends) != 1 || backends["openrouter"] == nil {
+		t.Fatalf("backend asset must define only openrouter: %v", backends)
 	}
-
-	decoder := json.NewDecoder(bytes.NewReader(data))
-	decoder.DisallowUnknownFields()
-	var value manifest
-	if err := decoder.Decode(&value); err != nil {
-		t.Fatalf("decode manifest: %v", err)
-	}
-	if err := requireJSONEnd(decoder); err != nil {
-		t.Fatalf("decode manifest: %v", err)
-	}
-	if value.SchemaVersion != 1 ||
-		value.ID != "openrouter" ||
-		value.Endpoint != "https://openrouter.ai/api/v1" ||
-		value.APIKeyEnv != "OPENROUTER_API_KEY" ||
-		value.ConcurrencyLimit != 16 ||
-		value.QueueCapacity != 1024 ||
-		string(value.ExtraParams) != "null" {
-		t.Fatalf("unexpected manifest: %#v", value)
-	}
-}
-
-func requireJSONEnd(decoder *json.Decoder) error {
-	var trailing any
-	if err := decoder.Decode(&trailing); errors.Is(err, io.EOF) {
-		return nil
-	} else if err != nil {
-		return err
-	}
-	return errors.New("catalog manifest must contain exactly one JSON value")
-}
-
-func assertOpenRouterProfile(t *testing.T, path string, data []byte) string {
-	t.Helper()
-
-	var document yaml.Node
-	decoder := yaml.NewDecoder(bytes.NewReader(data))
-	if err := decoder.Decode(&document); err != nil {
-		t.Fatalf("decode profile %s: %v", path, err)
-	}
-	if err := requireYAMLEnd(decoder); err != nil {
-		t.Fatalf("decode profile %s: %v", path, err)
-	}
-	if document.Kind != yaml.DocumentNode || len(document.Content) != 1 || document.Content[0].Kind != yaml.MappingNode {
-		t.Fatalf("profile %s must contain one mapping document", path)
-	}
-
-	fields := yamlFields(document.Content[0])
-	idField := fields["id"]
-	if idField == nil {
-		t.Fatalf("profile %s has no ID", path)
-	}
-	id := strings.TrimSpace(idField.Value)
-	if id == "" {
-		t.Fatalf("profile %s has a blank ID", path)
-	}
-	if fields["backend"] == nil || fields["backend"].Value != "openrouter" {
-		t.Fatalf("profile %s does not select openrouter", path)
-	}
-	for _, field := range []string{"endpoint", "api_key_env", "api_key"} {
-		if fields[field] != nil {
-			t.Fatalf("profile %s contains prohibited %s field", path, field)
+	definition := mappingFields(t, "backend", backends["openrouter"])
+	for field, want := range map[string]string{
+		"endpoint": "https://openrouter.ai/api/v1", "api_key_env": "OPENROUTER_API_KEY",
+		"concurrency_limit": "16", "queue_capacity": "1024",
+	} {
+		value := definition[field]
+		if value == nil || value.Value != want {
+			t.Fatalf("backend %s: got %v, want %q", field, value, want)
 		}
 	}
-	if extraParams := fields["extra_params"]; extraParams != nil {
-		assertNoSecretKeys(t, path, extraParams)
+	if len(definition) != 4 {
+		t.Fatalf("unexpected backend fields: %v", definition)
 	}
-	return id
 }
 
-func requireYAMLEnd(decoder *yaml.Decoder) error {
+func assertProfile(t *testing.T, assetPath string, data []byte) string {
+	t.Helper()
+	root := decodeMapping(t, assetPath, data)
+	profiles := requireSingleMapping(t, assetPath, root, "profiles")
+	if len(profiles) != 1 {
+		t.Fatalf("profile asset %s must define exactly one ID", assetPath)
+	}
+	for id, entry := range profiles {
+		if id == "" || id != strings.TrimSuffix(path.Base(assetPath), ".yml") {
+			t.Fatalf("profile asset %s has unexpected ID %q", assetPath, id)
+		}
+		fields := mappingFields(t, assetPath, entry)
+		if fields["backend"] == nil || fields["backend"].Value != "openrouter" {
+			t.Fatalf("profile %s does not select openrouter", assetPath)
+		}
+		if fields["model"] == nil || strings.TrimSpace(fields["model"].Value) == "" {
+			t.Fatalf("profile %s has no model", assetPath)
+		}
+		for _, obsolete := range []string{"id", "base_profile"} {
+			if fields[obsolete] != nil {
+				t.Fatalf("profile %s contains obsolete %s field", assetPath, obsolete)
+			}
+		}
+		return id
+	}
+	panic("unreachable")
+}
+
+func decodeMapping(t *testing.T, name string, data []byte) *yaml.Node {
+	t.Helper()
+	decoder := yaml.NewDecoder(bytes.NewReader(data))
+	var document yaml.Node
+	if err := decoder.Decode(&document); err != nil {
+		t.Fatalf("decode %s: %v", name, err)
+	}
 	var trailing yaml.Node
-	if err := decoder.Decode(&trailing); errors.Is(err, io.EOF) {
-		return nil
-	} else if err != nil {
-		return err
+	if err := decoder.Decode(&trailing); !errors.Is(err, io.EOF) {
+		t.Fatalf("%s must contain exactly one YAML document: %v", name, err)
 	}
-	return errors.New("profile must contain exactly one YAML document")
+	if document.Kind != yaml.DocumentNode || len(document.Content) != 1 || document.Content[0].Kind != yaml.MappingNode {
+		t.Fatalf("%s must contain one mapping document", name)
+	}
+	return document.Content[0]
 }
 
-func yamlFields(mapping *yaml.Node) map[string]*yaml.Node {
-	fields := make(map[string]*yaml.Node, len(mapping.Content)/2)
-	for index := 0; index+1 < len(mapping.Content); index += 2 {
-		fields[mapping.Content[index].Value] = mapping.Content[index+1]
+func requireSingleMapping(t *testing.T, name string, parent *yaml.Node, key string) map[string]*yaml.Node {
+	t.Helper()
+	fields := mappingFields(t, name, parent)
+	if len(fields) != 1 || fields[key] == nil {
+		t.Fatalf("%s must contain only %s", name, key)
+	}
+	return mappingFields(t, name, fields[key])
+}
+
+func mappingFields(t *testing.T, name string, node *yaml.Node) map[string]*yaml.Node {
+	t.Helper()
+	if node.Kind != yaml.MappingNode {
+		t.Fatalf("%s must contain a mapping", name)
+	}
+	fields := make(map[string]*yaml.Node, len(node.Content)/2)
+	for index := 0; index+1 < len(node.Content); index += 2 {
+		key := node.Content[index].Value
+		if _, exists := fields[key]; exists {
+			t.Fatalf("%s repeats key %q", name, key)
+		}
+		fields[key] = node.Content[index+1]
 	}
 	return fields
 }
-
-func assertNoSecretKeys(t *testing.T, path string, node *yaml.Node) {
-	t.Helper()
-
-	forbidden := map[string]bool{
-		"api_key":       true,
-		"apikey":        true,
-		"authorization": true,
-		"credential":    true,
-		"credentials":   true,
-		"password":      true,
-		"secret":        true,
-		"token":         true,
-		"access_token":  true,
-	}
-	var visit func(*yaml.Node)
-	visit = func(current *yaml.Node) {
-		if current.Kind == yaml.MappingNode {
-			for index := 0; index+1 < len(current.Content); index += 2 {
-				if forbidden[strings.ToLower(current.Content[index].Value)] {
-					t.Fatalf("profile %s contains a prohibited extra_params key", path)
-				}
-				visit(current.Content[index+1])
-			}
-			return
-		}
-		for _, child := range current.Content {
-			visit(child)
-		}
-	}
-	visit(node)
-}
diff --git a/docs/release.md b/docs/release.md
index 6d2fd74..632c869 100644
--- a/docs/release.md
+++ b/docs/release.md
@@ -1,11 +1,11 @@
 # Catalog Release Procedure
 
 This repository releases source tags only. It has no generated artifacts. The
-module path is `gitea.maximumdirect.net/eric/promptkit-backend-openrouter/v2`.
+module path is `gitea.maximumdirect.net/eric/promptkit-backend-openrouter/v3`.
 
 ## Version selection
 
-Release versions use `v2.YYYYMMDD.N`. `YYYYMMDD` is the actual UTC publication
+Release versions use `v3.YYYYMMDD.N`. `YYYYMMDD` is the actual UTC publication
 date. Begin at revision `0` for a date and increment `N` for each additional
 release on that date. Versions are immutable: correct a published catalog with
 a new dated version rather than moving or recreating a tag. This repository
@@ -20,7 +20,7 @@ tree is active, then run `GOWORK=off go test ./...`, `GOWORK=off go test -race
 ./...`, `GOWORK=off go vet ./...`, `GOWORK=off go build ./...`, formatting,
 repository-hygiene, credential, and ordinary module-resolution checks.
 
-Confirm the module reports the `/v2` identity before publication. Create an
+Confirm the module reports the `/v3` identity before publication. Create an
 annotated tag only after validation succeeds. Do not create or move an existing
 tag. Publish the validated source commit through `main`, then push only the
 selected annotated tag and verify that the remote tag and its peeled commit
@@ -28,5 +28,5 @@ identify that source commit.
 
 Finally, from a temporary module with `GOWORK=off`, no workspace, no
 replacement, and no vendor tree, resolve the exact published
-`gitea.maximumdirect.net/eric/promptkit-backend-openrouter/v2@version`. Verify
+`gitea.maximumdirect.net/eric/promptkit-backend-openrouter/v3@version`. Verify
 both the resolved module identity and version match the selected tag.
diff --git a/go.mod b/go.mod
index 0681d0a..0e1f2bd 100644
--- a/go.mod
+++ b/go.mod
@@ -1,4 +1,4 @@
-module gitea.maximumdirect.net/eric/promptkit-backend-openrouter/v2
+module gitea.maximumdirect.net/eric/promptkit-backend-openrouter/v3
 
 go 1.25.5