AI-Agent-Gemini

AI Agent Gemini plugin for CodeOnTheGo

Google Gemini API inference for CodeOnTheGo's AI plugins. Registers itself as the gemini backend with ai-core's LlmInferenceService, which is what ai-core's Agent chat, Code-Suggestions, Speech-to-Text and Vector-Search actually talk to.

Calls the Generative Language REST API directly over HttpURLConnection rather than the google-genai SDK: the SDK bundles OkHttp 4.x, but plugins run in the host IDE's classloader where okhttp3 resolves to the host's older OkHttp, and that mismatch crashed generation with a NoSuchMethodError.

Building

Prerequisites: Android SDK (API 33+), JDK 17. Create local.properties with sdk.dir=.... This plugin uses the shared wrapper at the repo root:

cd plugins/AI-Agent-Gemini
../../gradlew assemblePlugin          # release  -> build/plugin/ai-agent-gemini.cgp
../../gradlew assemblePluginDebug     # debug variant

API key handling

The key is entered in AI Core → Agent settings, not here. It is stored encrypted (AES/GCM under a hardware-backed Android Keystore secret) and sent as an x-goog-api-key header, never in a URL query string.

security/SecureApiKeyStore.kt holds only this plugin's Keystore alias (cotg_ai_gemini_key_v1); the AES/GCM itself is the IDE's KeystoreSecretStore (plugin-api, since 26.36 — hence this plugin's min_ide_version), so there is one implementation in the process rather than a copy per plugin. The alias stays per plugin: they all share the host's Keystore, so a shared alias would let one plugin's invalidated-key recovery delete another's secret. A key written under an earlier plugin id is adopted once by preferences/GeminiPreferences.kt and re-encrypted here.

Installation

Install ai-core as well — without the router this plugin has nothing to register with. Order does not matter: this plugin re-registers when it sees ai-core activate. Copy build/plugin/ai-agent-gemini.cgp to the device, install via CodeOnTheGo's Plugin Manager, then restart the IDE.

Cross-plugin contract

This plugin's own settings pane calls GeminiBackend.listModels() and listModels(String) directly (see BackendGeminiCatalogGateway in settings/GeminiCatalogGateway.kt) to populate the model picker and to verify a key before it is saved. Those two signatures, and the ListModels HTTP <code> message shape thrown by fetchAvailableModels, are a contract — the pane is mounted by ai-core across the plugin classloader boundary, so proguard-rules.pro pins the class and its public methods.

System prompt config

The prompt Gemini asks ai-core to send lives in src/main/assets/prompts/, one YAML file per concern, apart from the code that sends it. Changing the tone, adding a rule or translating the prompt is an edit to those files alone. ai-core appends its own IDE CONTEXT block after the rendered prompt.

The files are loaded, validated and cached once, when the plugin is activated. getSystemPrompt renders layout.yml from that cache for each request, since the tool list, the protocol and the example path vary per run; it never waits. Until the config has loaded, or if it cannot render, it returns null and ai-core sends its own default prompt.

File	Keys	What it is
agent.yml	schema_version, identity, include	The entry point: the version (1; another is refused rather than misread), who the agent is, and the files below.
scope.yml	scope	What the agent will answer: anything, with the project's tools only when the request is about the open project.
rules.yml	rules	Priority groups, highest first; each has a heading (CRITICAL, IMPORTANT, MANDATORY, OPTIONAL) and its items. Adding a rule is adding an item.
workflow.yml	behavior, workflow	How to go about building or changing something; the workflow's steps are numbered when rendered.
tools.yml	tools, tool_call_format	What introduces the tool list, and how to call a tool: native under the function-calling API, text (with its examples) when calls travel in the reply. Exactly one is sent.
layout.yml	layout.system_prompt	Where each text goes.

Loading and checking follow ai-core's rules (see ai-core's README): a key belongs to one file, only agent.yml includes, and a missing, unknown, misspelled or duplicate key, an empty list or an unquoted number is refused naming the file and path, e.g. rules.yml: rules[1].items is empty. Texts are named by their YAML path in upper case (scope.heading is SCOPE_HEADING); each rule group has HEADING and ITEMS, each item and step has TEXT, each step has NUMBER, and each example has PURPOSE and CALL. The request's values are TOOLS (each with NAME, DESCRIPTION, inserted verbatim), TOOL_CALL_SYNTAX (null under native calling), NATIVE_TOOL_CALLS, EXAMPLE_FILE_PATH and EXAMPLE_FILE_STEM.

Rendering is strict: an unknown name throws, naming the text it was in. Activation renders the prompt for requests that open and close every section and logs any failure, and GeminiSystemPromptTest fails on one in the shipped files. A new key needs GeminiPromptConfig and its parser; a new name needs GeminiPromptVariables.

The engine and the YAML plumbing (PromptTemplateEngine, PromptConfigLoader, PromptConfigStore, PromptConfigObject, ...) are the IDE's, in plugin-api.jar's com.itsaky.androidide.plugins.ai.prompt, shared with ai-core and the other backends. Only GeminiPromptConfig, its mapping in GeminiPromptConfigParser, and sharedPromptConfig are this plugin's own.

Key classes

Every source file sits in a package named for its layer; nothing is loose at the root of com/itsaky/androidide/plugins/aiagentgemini/.

• plugin/GeminiPlugin.kt — plugin entry point; registers the backend with ai-core
• backend/GeminiBackend.kt — the REST transport, streaming (SSE), embeddings and model catalog
• backend/GeminiEmbeddingProtocol.kt — the batchEmbedContents body, per-call cap and positional reply (pure)
• errors/GeminiErrorFormatter.kt — turns an API failure into one translated sentence
• security/SecureApiKeyStore.kt — this plugin's Keystore alias, over the IDE's KeystoreSecretStore
• preferences/GeminiPreferences.kt — this plugin's settings store, plus the one-time adoption of settings written under earlier plugin ids
• prompt/GeminiSystemPrompt.kt — renders layout.yml from GeminiPromptVariables; prompt/config/ maps assets/prompts/ onto this plugin's config type, which the IDE's ai.prompt package loads, validates, caches and renders
• logging/ — LOG_PREFIX (AiAgentGemini), prefixing every logcat tag this plugin writes
• settings/ — the settings pane this backend contributes to the selector

License

GPL-3.0 — same as AndroidIDE / CodeOnTheGo.