mirror of
https://github.com/langbot-app/LangBot.git
synced 2026-10-30 12:25:29 +08:00
108 lines
5.0 KiB
Markdown
108 lines
5.0 KiB
Markdown
# Langflow Agent
|
|
|
|
Tweaks must be a JSON object (a JSON string or an object). Missing, null, empty, or whitespace-only input means no overrides. Invalid JSON and other values fail with `langflow.config_invalid` without logging the payload. Whitespace-only input is a plugin convenience; native Langflow rejected it. Conversation history remains persistent through `external.session_id`; migration does not restore the native fresh-session-per-request behavior.
|
|
|
|
Run a Langflow flow as a LangBot Runner.
|
|
|
|
## Runner ID
|
|
|
|
`plugin:langbot-team/LangflowAgent/default`
|
|
|
|
## Configuration
|
|
|
|
| Field | Type | Required | Default | Description |
|
|
| --- | --- | --- | --- | --- |
|
|
| base-url | string | yes | http://localhost:7860 | Langflow server URL |
|
|
| api-key | secret | yes | '' | Langflow API key |
|
|
| flow-id | string | yes | '' | Flow ID |
|
|
| advanced-settings | boolean | no | false | Show input, output, and flow tweak controls |
|
|
| input-type | string | no | chat | Input type |
|
|
| output-type | string | no | chat | Output type |
|
|
| tweaks | json | no | {} | Flow tweaks |
|
|
| langbot-assets-enabled | boolean | no | false | Register a short-lived LangBot asset token for each run and inject it into the flow via a tweak |
|
|
| langbot-assets-gateway-host | string | no | 0.0.0.0 | Host for the local LangBot Asset Gateway |
|
|
| langbot-assets-gateway-port | integer | no | 8765 | Port for the local LangBot Asset Gateway |
|
|
| langbot-assets-gateway-request-timeout | integer | no | 60 | Timeout for individual gateway tool calls |
|
|
| langbot-assets-token-ttl | integer | no | 3600 | Lifetime of each run token in seconds |
|
|
| langbot-assets-input-name | string | no | langbot_asset_run_token | Flow component (name/id) whose `input_value` receives the run token |
|
|
|
|
## LangBot Asset Callback Through Langflow MCP Tools
|
|
|
|
Langflow can call back into LangBot assets through the SDK Asset Gateway, the same
|
|
mechanism the Dify runner uses. The gateway is a run-token-authorized MCP server
|
|
(`POST /mcp`, JSON-RPC) exposing the run-authorized LangBot tools:
|
|
`langbot_list_assets`, `langbot_get_current_event`, `langbot_history_page`,
|
|
`langbot_retrieve_knowledge`, `langbot_get_tool_detail`, and `langbot_call_tool`.
|
|
|
|
### How it works
|
|
|
|
1. When `langbot-assets-enabled` is true, this runner registers a short-lived,
|
|
run-scoped token before calling the flow and injects it into the run via a
|
|
tweak: it sets the `input_value` of the component named by
|
|
`langbot-assets-input-name` (default `langbot_asset_run_token`) to the token.
|
|
2. The flow's Agent reads that value and passes it as the `run_token` argument on
|
|
every LangBot MCP tool call.
|
|
3. The runner removes the token when the run ends. Tool calls without a valid
|
|
token are rejected by the gateway.
|
|
|
|
The gateway accepts the token via an `Authorization: Bearer` header or via a
|
|
`run_token` tool-call argument. Use the **`run_token` argument** approach here.
|
|
|
|
### Build the flow
|
|
|
|
1. Add a **Text Input** (or similar) component whose name/id matches
|
|
`langbot-assets-input-name`. The runner sets its `input_value` to the token
|
|
each run. (Leave its value empty by default.)
|
|
2. Add an **MCP Tools / MCP Connection** component:
|
|
- Transport: streamable HTTP.
|
|
- URL: the public URL routing to the gateway `/mcp`, e.g. `https://example.com/mcp`.
|
|
3. Add an **Agent** component, attach the MCP Tools, and wire the token component
|
|
into the Agent so its instructions pass `run_token` on every LangBot tool call,
|
|
for example:
|
|
|
|
```text
|
|
For every LangBot MCP tool call, set run_token exactly to the provided
|
|
LangBot run token. Call langbot_list_assets first to discover available
|
|
LangBot assets for the current run.
|
|
```
|
|
|
|
### Configure LangBot
|
|
|
|
Select the Langflow runner and set:
|
|
|
|
```text
|
|
base-url = http://localhost:7860
|
|
api-key = <Langflow API key>
|
|
flow-id = <flow id>
|
|
langbot-assets-enabled = true
|
|
langbot-assets-gateway-host = 0.0.0.0
|
|
langbot-assets-gateway-port = 8765
|
|
langbot-assets-token-ttl = 3600
|
|
langbot-assets-input-name = langbot_asset_run_token
|
|
```
|
|
|
|
The public MCP URL in the flow's MCP component must route to this same gateway
|
|
instance. The runner only injects the short-lived token into the flow tweak; it
|
|
does not create or update the flow's MCP component.
|
|
|
|
### Limitations
|
|
|
|
- A remote/cloud Langflow that cannot reach `localhost` needs a public HTTPS URL
|
|
for the gateway `/mcp` endpoint.
|
|
- The run token is short-lived and run-scoped; the flow must complete its asset
|
|
callbacks within the flow run.
|
|
- The gateway exposes only the assets permitted by the current run: current
|
|
event, history page, knowledge retrieval, tool detail, and tool call.
|
|
- The flow must have a component whose name/id matches `langbot-assets-input-name`
|
|
for the tweak injection to land; otherwise the token never reaches the Agent.
|
|
Verify the `tools/list` handshake against your gateway when setting this up.
|
|
|
|
## Legacy Runner
|
|
|
|
Migrated from `langflow-api` in LangBot.
|
|
|
|
|
|
## Dedicated runtime placement
|
|
|
|
This release is unsigned and dedicated. Historical shared-runtime notes in [SHARED_RUNTIME.md](SHARED_RUNTIME.md) do not grant shared-worker eligibility.
|