Introduction
This technical page covers shared application and administrator environment variables for self-hosted FastGPT, including required secrets, database configuration, and core deployment settings. These variables standardize configuration across both app and admin workflows, ensuring consistent security and functionality for your FastGPT instance.
Full Variable Reference
The following table lists all supported shared environment variables, their default values, and official descriptions:
| Variable | Default | Description |
|---|---|---|
DB_MAX_LINK | 5 | Maximum connection pool size for MongoDB, PG, OceanBase, openGauss, and other databases. |
SYNC_INDEX | true | Whether to create missing MongoDB indexes and remove explicitly declared deprecated indexes at startup. Maintain indexes manually when disabled. |
FILE_TOKEN_KEY | None, required | Secret for file read and file authorization flows. Must be at least 6 characters. |
AES256_SECRET_KEY | None, required | Secret used by AES encryption and decryption. Must be at least 6 characters. |
INVOKE_TOKEN_SECRET | None, required | JWT secret for Invoke reverse calls. Must be at least 32 characters. |
ROOT_KEY | fastgpt_root_key | Admin API key for the current system. It can call /api/admin/** APIs and must be at least 6 characters. |
PRO_TOKEN | Empty | Token for FastGPT app server calls to pro/admin internal APIs. It must match the pro/admin configuration and is required when App configures PRO_URL. |
PRO_URL | Empty | Commercial service URL. When set, App can call Pro APIs, and the domain is allowed by file URL validation. |
Deployment Best Practices
All variables marked required must be configured before launching your FastGPT instance, with enforced minimum length requirements to prevent weak security configurations. For example, INVOKE_TOKEN_SECRET requires a minimum of 32 characters, while file and AES secrets require at least 6 characters.
The default ROOT_KEY uses a generic default value; replace it with a custom, secure value for production deployments to restrict unauthorized admin API access.
If PRO_URL is set, PRO_TOKEN must be configured to match your pro/admin setup, as the token validates internal API calls between the app and commercial services.
The SYNC_INDEX variable defaults to true, which automatically manages MongoDB indexes at startup; disable this only if you intend to manually maintain database indexes. Adjust DB_MAX_LINK based on your database server's connection capacity to optimize performance for your deployment size.
Source: FastGPT official source
Applicability and version scope
Use this page for the documented Deployment and upgrades scenario. Confirm the FastGPT, dependency, API, and deployment versions in the official source before applying a change.
Safety guardrails
Use [REDACTED_CREDENTIAL] for credentials and private data. Confirm the documented environment and version before review.
Rollback guidance
Restore the prior technical-content authority snapshot. Restore saved configuration and data snapshots, then repeat the smallest verification scenario.