feat: ai-prompt-decorator plugin

apisix/cli/config.lua

@@ -214,6 +214,7 @@ local _M = {
     "proxy-cache",
     "body-transformer",
     "ai-prompt-template",
+    "ai-prompt-decorator",
     "proxy-mirror",
     "proxy-rewrite",
     "workflow",

apisix/plugins/ai-prompt-decorator.lua

@@ -0,0 +1,117 @@
+--
+-- Licensed to the Apache Software Foundation (ASF) under one or more
+-- contributor license agreements.  See the NOTICE file distributed with
+-- this work for additional information regarding copyright ownership.
+-- The ASF licenses this file to You under the Apache License, Version 2.0
+-- (the "License"); you may not use this file except in compliance with
+-- the License.  You may obtain a copy of the License at
+--
+--     http://www.apache.org/licenses/LICENSE-2.0
+--
+-- Unless required by applicable law or agreed to in writing, software
+-- distributed under the License is distributed on an "AS IS" BASIS,
+-- WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+-- See the License for the specific language governing permissions and
+-- limitations under the License.
+--
+local core  = require("apisix.core")
+local ngx   = ngx
+local pairs = pairs
+local EMPTY = {}
+
+local prompt_schema = {
+    properties = {
+        role = {
+            type = "string",
+            enum = { "system", "user", "assistant" }
+        },
+        content = {
+            type = "string",
+            minLength = 1,
+        }
+    },
+    required = { "role", "content" }
+}
+
+local prompts = {
+    type = "array",
+    items = prompt_schema
+}
+
+local schema = {
+    type = "object",
+    properties = {
+        prepend = prompts,
+        append = prompts,
+    },
+    anyOf = {
+        { required = { "prepend" } },
+        { required = { "append" } },
+        { required = { "append", "prepend" } },
+    },
+}
+
+
+local _M = {
+    version  = 0.1,
+    priority = 1070,
+    name     = "ai-prompt-decorator",
+    schema   = schema,
+}
+
+
+function _M.check_schema(conf)
+    return core.schema.check(schema, conf)
+end
+
+
+local function get_request_body_table()
+    local body, err = core.request.get_body()
+    if not body then
+        return nil, { message = "could not get body: " .. err }
+    end
+
+    local body_tab, err = core.json.decode(body)
+    if not body_tab then
+        return nil, { message = "could not get parse JSON request body: " .. err }
+    end
+
+    return body_tab
+end
+
+
+local function decorate(conf, body_tab)
+    local new_messages = conf.prepend or EMPTY
+    for _, message in pairs(body_tab.messages) do
+        core.table.insert_tail(new_messages, message)
+    end
+
+    for _, message in pairs(conf.append or EMPTY) do
+        core.table.insert_tail(new_messages, message)
+    end
+
+    body_tab.messages = new_messages
+end
+
+
+function _M.rewrite(conf, ctx)
+    local body_tab, err = get_request_body_table()
+    if not body_tab then
+        return 400, err
+    end
+
+    if not body_tab.messages then
+        return 400, "messages missing from request body"
+    end
+    decorate(conf, body_tab) -- will decorate body_tab in place
+
+    local new_jbody, err = core.json.encode(body_tab)
+    if not new_jbody then
+        return 500, { message = "failed to parse modified JSON request body: " .. err }
+    end
+
+    ngx.req.set_body_data(new_jbody)
+end
+
+
+return _M

apisix/plugins/ai-prompt-template.lua

@@ -72,7 +72,7 @@ local schema = {
 
 local _M = {
     version  = 0.1,
-    priority = 1060,
+    priority = 1071,
     name     = "ai-prompt-template",
     schema   = schema,
 }

conf/config.yaml.example

@@ -476,7 +476,8 @@ plugins:                           # plugin list (sorted by priority)
   #- error-log-logger              # priority: 1091
   - proxy-cache                    # priority: 1085
   - body-transformer               # priority: 1080
-  - ai-prompt-template             # priority: 1060
+  - ai-prompt-template             # priority: 1071
+  - ai-prompt-decorator            # priority: 1070
   - proxy-mirror                   # priority: 1010
   - proxy-rewrite                  # priority: 1008
   - workflow                       # priority: 1006

docs/en/latest/config.json

@@ -87,6 +87,7 @@
           "type": "category",
           "label": "Transformation",
           "items": [
+            "plugins/ai-prompt-decorator",
             "plugins/response-rewrite",
             "plugins/proxy-rewrite",
             "plugins/grpc-transcode",

docs/en/latest/plugins/ai-prompt-decorator.md

@@ -0,0 +1,109 @@
+---
+title: ai-prompt-decorator
+keywords:
+  - Apache APISIX
+  - API Gateway
+  - Plugin
+  - ai-prompt-decorator
+description: This document contains information about the Apache APISIX ai-prompt-decorator Plugin.
+---
+
+<!--
+#
+# Licensed to the Apache Software Foundation (ASF) under one or more
+# contributor license agreements.  See the NOTICE file distributed with
+# this work for additional information regarding copyright ownership.
+# The ASF licenses this file to You under the Apache License, Version 2.0
+# (the "License"); you may not use this file except in compliance with
+# the License.  You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+-->
+
+## Description
+
+The `ai-prompt-decorator` plugin simplifies access to LLM providers, such as OpenAI and Anthropic, and their models by appending or prepending prompts into the request.
+
+## Plugin Attributes
+
+| **Field**         | **Required**    | **Type** | **Description**                                     |
+| ----------------- | --------------- | -------- | --------------------------------------------------- |
+| `prepend`         | Conditionally\* | Array    | An array of prompt objects to be prepended          |
+| `prepend.role`    | Yes             | String   | Role of the message (`system`, `user`, `assistant`) |
+| `prepend.content` | Yes             | String   | Content of the message. Minimum length: 1           |
+| `append`          | Conditionally\* | Array    | An array of prompt objects to be appended           |
+| `append.role`     | Yes             | String   | Role of the message (`system`, `user`, `assistant`) |
+| `append.content`  | Yes             | String   | Content of the message. Minimum length: 1           |
+
+\* **Conditionally Required**: At least one of `prepend` or `append` must be provided.
+
+## Example usage
+
+Create a route with the `ai-prompt-decorator` plugin like so:
+
+```shell
+curl "http://127.0.0.1:9180/apisix/admin/routes/1" -X PUT \
+  -H "X-API-KEY: ${ADMIN_API_KEY}" \
+  -d '{
+    "uri": "/v1/chat/completions",
+    "plugins": {
+      "ai-prompt-decorator": {
+        "prepend":[
+          {
+            "role": "system",
+            "content": "I have exams tomorrow so explain conceptually and briefly"
+          }
+        ],
+        "append":[
+          {
+            "role": "system",
+            "content": "End the response with an analogy."
+          }
+        ]
+      }
+    },
+    "upstream": {
+      "type": "roundrobin",
+      "nodes": {
+        "api.openai.com:443": 1
+      },
+      "pass_host": "node",
+      "scheme": "https"
+    }
+  }'
+```
+
+Now send a request:
+
+```shell
+curl http://127.0.0.1:9080/v1/chat/completions -i -XPOST  -H 'Content-Type: application/json' -d '{
+  "model": "gpt-4",
+  "messages": [{ "role": "user", "content": "What is TLS Handshake?" }]
+}' -H "Authorization: Bearer <your token here>"
+```
+
+Then the request body will be modified to something like this:
+
+```json
+{
+  "model": "gpt-4",
+  "messages": [
+    {
+      "role": "system",
+      "content": "I have exams tomorrow so explain conceptually and briefly"
+    },
+    { "role": "user", "content": "What is TLS Handshake?" },
+    {
+      "role": "system",
+      "content": "End the response with an analogy."
+    }
+  ]
+}
+```

t/admin/plugins.t

@@ -94,6 +94,7 @@ authz-keycloak
 proxy-cache
 body-transformer
 ai-prompt-template
+ai-prompt-decorator
 proxy-mirror
 proxy-rewrite
 workflow