Gemini component

Q: What happens on an API error?

The exchange fails with HttpOperationFailedException and the API's error message (for example API key not valid). 429 and 5xx answers are retried first (maxRetries).

Q: Can I test routes that use it without calling Gemini?

Yes. Record the responses once (record=file:gemini.jsonl) and replay them (replay=...); cameleer test runs the route against them (testing without a model). cameleer_saas::testing::GeminiMock is a mock of the API for Rust tests: it scripts tool calls and rejects a functionCall sent back without its thought signature.

The gemini component calls Google's Gemini models through the Gemini API (Google AI Studio, API keys), with tool calling: with tags it runs your ai-tool routes for the model, and it is a model for the agent step.

Scheme: gemini: · Crate: cameleer-saas · Cargo feature: saas · Consumer: no · Producer: yes · Apache Camel: no direct equivalent (Camel reaches Gemini through LangChain4j or google-vertexai)

When to use it

Call Gemini with an API key, without a Google Cloud project or service account.
Give Gemini your routes as tools, with argument checks, approvals and an audit log (ai-tool).
Use Gemini as the model of an agent step.

For Vertex AI (service accounts, regions, VPC) use google-vertexai. For Gemini's OpenAI-compatible API use openai:chat-completion?provider=gemini; this component keeps what that API drops, such as thought signatures.

URI format

text

gemini:generate[?options]

Example

yaml example: gemini-tools

- route:
    from:
      uri: direct:ask
      steps:
        - to: "gemini:generate?model=gemini-2.5-flash&apiKey={{env:GEMINI_API_KEY}}&systemMessage=You are a support agent.&tags=support"

A text body is the user's message and becomes the answer. With tags, the model can call the ai-tool routes with those tags; each functionCall runs through the ai-tool envelope and its thoughtSignature is sent back with it, as Gemini requires.

Options

option	default	description
`model`	required	The model, such as `gemini-2.5-flash` (the `CamelGeminiModel` header overrides it)
`apiKey`	`GEMINI_API_KEY`, then `GOOGLE_API_KEY` env	Sent as `x-goog-api-key`
`baseUrl`	`https://generativelanguage.googleapis.com`	The API base URL (a gateway or proxy)
`systemMessage`		The system instruction (the `CamelGeminiSystemMessage` header overrides it)
`maxTokens`		`generationConfig.maxOutputTokens`
`temperature`		`generationConfig.temperature`
`timeout`	`120s`	HTTP timeout
`tags`, `autoToolExecution`, `maxToolIterations`, `maxAgenticTokens`, `parallelToolExecution`, `hallucinatedToolNameStrategy`, `record`, `replay`		Tool calling, as on every model component (the options)
`maxRetries`, `retryDelay`, `fallbackModels`, `responseCache`, `responseCacheTtl`, `responseCacheSize`, `coalesce`		Retries, fallbacks, response cache and coalescing (model providers)

Message headers

header	direction	description
`CamelGeminiSystemMessage`	in	The system instruction
`CamelGeminiModel`	in	The model for this call
`CamelGeminiFinishReason`	out	Map bodies: the first candidate's `finishReason`
`CamelGeminiPromptTokenCount`, `CamelGeminiCandidatesTokenCount`	out	Token usage (all turns of a tool loop)
`CamelAiAgentTurns`, `CamelAiAgentToolCalls`, `CamelAiAgentStopReason`, `CamelAiAgentTotalTokens`	out	The tool loop
`CamelAiCacheReadTokens`	out	Input tokens served from Gemini's implicit cache (when there were any)
`CamelAiRequestedToolCalls`	out	With `autoToolExecution=false`: the calls Gemini asked for

Bodies: a text body is one user message; a list body is the message list ({"role", "content"}); a map body is sent as the whole generateContent request and the whole response becomes the body.

Common questions

What happens on an API error?

The exchange fails with HttpOperationFailedException and the API's error message (for example API key not valid). 429 and 5xx answers are retried first (maxRetries).

Can I test routes that use it without calling Gemini?

Yes. Record the responses once (record=file:gemini.jsonl) and replay them (replay=...); cameleer test runs the route against them (testing without a model). cameleer_saas::testing::GeminiMock is a mock of the API for Rust tests: it scripts tool calls and rejects a functionCall sent back without its thought signature.

Found a problem?

If something on this page doesn't match what Cameleer does, please open an issue, or fork the repository, fix it, add a test, run cargo test --workspace and open a pull request.