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Gemini

Build a WeChat Official Account AI Bot with Gemini

Step-by-step guide to running a Gemini-powered AI bot on WeChat Official Account with LangBot: model setup, bot credentials, networking, testing and troubleshooting.

This recipe puts a Gemini model behind a WeChat Official Account bot. LangBot receives messages from WeChat Official Account, runs them through a pipeline, and sends the answer back, so you do not write any platform code.

Use Google's Gemini models with LangBot's built-in Agent, including image input when the model supports vision.

What you need

  • A running LangBot instance: LangBot Cloud (no server needed) or a self-hosted deployment with Docker or uvx langbot.
  • A Gemini account or server you can call from LangBot.
  • A WeChat Official Account or Service Account: AppID, AppSecret, a server Token and EncodingAESKey, with LangBot's server IP in the IP whitelist.

Networking

Official Accounts require a public domain with HTTPS and must get a response within 5 seconds. Slow AI replies need passive or auto mode. LangBot Cloud includes a public domain.

1. Add the Gemini model

  1. Create an API key in the Google Gemini console.
  2. In LangBot, open Models, add an LLM model with the provider set to Google Gemini, then paste the API key and the model ID.
  3. Enable Tool Use if the model supports function calling; MCP tools, Skills and the sandbox need it.
  4. Create the key in Google AI Studio. Enable Vision on the model if you want the bot to read images.

2. Create a pipeline

Open Pipelines in the LangBot WebUI, create a pipeline (or edit the default one) and set AI as follows.

FieldValue
RunnerLocal Agent (built-in Agent)
ModelThe model you just added. You can add fallback models.
PromptInstructions: who the bot is, tone, what it must not do.
Knowledge BasesOptional. Attach a knowledge base so answers come from your documents.

3. Create the WeChat Official Account bot

  1. Create a bot with the WeChat Official Account adapter and choose a reply mode: drop (reply within the 5-second callback), passive or auto (answer later through the customer service API when the account is enterprise-verified).
  2. Paste the bot's callback URL into the account's server configuration and save.

4. Bind and test

Open the bot, select the pipeline you created, save and make sure the bot is enabled.

Follow the account in WeChat and send it a message.

Troubleshooting

  • Images are ignored: enable Vision on the model and check that the platform adapter forwards images.
  • Users see the loading message but no answer: in passive mode (or after auto falls back) the user must send another message to retrieve the queued answer.
  • Customer service messages require an enterprise-verified account; identity verification alone is not enough.
  • Check Monitoring in the WebUI: every message, pipeline run and error is recorded there.

FAQ

Do I need a server with a public IP for WeChat Official Account?

Yes, or use LangBot Cloud. Official Accounts require a public domain with HTTPS and must get a response within 5 seconds. Slow AI replies need passive or auto mode. LangBot Cloud includes a public domain.

Does the WeChat Official Account bot support streaming replies?

Check the platform feature matrix for what this platform supports. Replies are delivered once the AI back end has finished.

Can the same Gemini setup serve other platforms too?

Yes. A pipeline can be bound to many bots, so one configuration can answer on several platforms at once.

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