# Environment variables A list of the available environment variables used when running SurrealDB. Environment variables can be used to tailor the behaviour of a running SurrealDB instance. Environment variables are divided into four types: * **SurrealDB environment variables**: environment variables that pertain to the overall running of a SurrealDB server. Example: `SURREAL_DEFAULT_DATABASE`. Includes an [operator and internal config](#operator-and-internal-config) subsection for advanced settings. * **Command environment variables**: environment variables that can be used in lieu of a command flag. Example: `SURREAL_CAPS_ALLOW_ALL=true surreal start`, equivalent to `surreal start --allow-all`. * **Storage backend environment variables**: environment variables that pertain to a certain storage backend. Example: `SURREAL_SURREALKV_MAX_SEGMENT_SIZE`. * **SurrealDB Cloud environment variables**: environment variables that are set via the [Configure instance](/docs/manage/instances/configure.md) sidebar for a SurrealDB Cloud instance. > [!IMPORTANT] > Every variable on this page belongs to the `surreal` binary and starts with `SURREAL_`. The [`surrealctl`](/docs/reference/cli/surrealctl/overview.md) control-plane tool reads `SURREALCTL_*` variables instead, and the two prefixes are kept apart deliberately: a database credential such as `SURREAL_TOKEN` is not a control-plane credential, and must not be sent to the SurrealDB Cloud API. Many environment variables have a maximum value equivalent to the greatest possible `usize`, which is an unsigned integer with a number of bytes depending on the target that the database runs on. For most systems this will be 64 bits, leading to a maximum size of 18_446_744_073_709_551_615 (264), while for 32 bits the maximum will be 4_294_967_296 (232). ## Byte size suffixes _(since v3.0.0)_ Environment variables that set a size in bytes, such as `SURREAL_HTTP_MAX_SQL_BODY_SIZE` and `SURREAL_WEBSOCKET_MAX_MESSAGE_SIZE`, accept either a raw byte count or a number with a suffix. Suffixes are case-insensitive, and all of them are powers of 1024, so `4GB` and `4GiB` both mean 4,294,967,296 bytes. | Suffix | Multiplier | | ------ | ---------- | | none, `b` | 1 | | `k`, `kb`, `kib` | 1024 | | `m`, `mb`, `mib` | 10242 | | `g`, `gb`, `gib` | 10243 | > [!WARNING] > A value that cannot be parsed is discarded and the default is used instead - the server does not fail to start. On 2.x these variables take a raw byte count only, so a suffixed value such as `16MiB` is silently ignored there and the default remains in effect. ## SurrealDB environment variables These environment variables can be used to configure a SurrealDB server to configure areas such as the HTTP server and client, limits, telemetry, and so on. ### Batch config
Environment variable Default Allowed values Notes
SURREAL_NORMAL_FETCH_SIZE 500 A usize The maximum number of keys that should be scanned at once in general queries.
SURREAL_EXPORT_BATCH_SIZE 1000 A usize The maximum number of keys that should be scanned at once for export queries.
SURREAL_COUNT_BATCH_SIZE_(since v2.2.0)_ 10,000 A usize The maximum number of keys that should be scanned at once for count queries.
SURREAL_INDEXING_BATCH_SIZE 250 A usize The maximum number of keys to scan at once per concurrent indexing batch.
### Cache config
Environment variable Default Allowed values Notes
SURREAL_TRANSACTION_CACHE_SIZE 10,000 A usize Specifies the number of items which can be cached within a single transaction.
SURREAL_DATASTORE_CACHE_SIZE 1,000 A usize The number of definitions which can be cached across transactions.
SURREAL_HNSW_CACHE_SIZE 268,435,456 (256 MiB) A usize The maximum total size, in bytes, of the HNSW vector cache, shared across all HNSW indexes in the process. This bounds the cached element vectors used for distance computation - it is not a cap on total HNSW memory: the adjacency graph is loaded into resident memory on first use and stays there, outside this budget. Contrast SURREAL_DISKANN_CACHE_SIZE, which does page graph structure.
SURREAL_DISKANN_CACHE_SIZE_(since v3.1.0)_ 268,435,456 (256 MiB) A usize The maximum total size, in bytes, of the DISKANN index cache, shared across all DISKANN indexes in the process. DISKANN graph data lives in the key-value store and is paged through this bounded cache. The DISKANN counterpart of SURREAL_HNSW_CACHE_SIZE.
### File config Server-side filesystem access for features that read paths from disk (notably the `mapper()` filter on [`DEFINE ANALYZER`](/docs/reference/query-language/statements/define/analyzer.md)). This is separate from `SURREAL_BUCKET_FOLDER_ALLOWLIST` (below), which gates the experimental [files](/docs/learn/schema-management/files/buckets.md) feature.
Environment variable Default Allowed values Notes
SURREAL_FILE_ALLOWLIST none (deny all) Colon-separated paths on Unix; semicolon-separated on Windows Directories the server may read when an analyzer uses mapper('<path>'). An empty or unset value denies every path. Each dictionary file must resolve under one of the listed directories. See DEFINE ANALYZER - mapper.
SURREAL_BUCKET_FOLDER_ALLOWLIST none Comma-separated paths Specifies a list of paths in which files can be accessed.
SURREAL_GLOBAL_BUCKET none A string Specifies the name of a global bucket for file data.
SURREAL_GLOBAL_BUCKET_ENFORCED false true, false Whether to enforce a global bucket for file data.
### HTTP client config
Environment variable Default Allowed values Notes
SURREAL_MAX_HTTP_REDIRECTS 10 A usize The maximum number of HTTP redirects allowed within http functions.
SURREAL_MAX_HTTP_IDLE_CONNECTIONS_PER_HOST 128 A usize The maximum number of idle HTTP connections to maintain per host.
SURREAL_MAX_HTTP_IDLE_CONNECTIONS 1000 A usize The maximum number of idle HTTP connections to maintain.
SURREAL_HTTP_IDLE_TIMEOUT_SECS 90 A usize The timeout for idle HTTP connections before closing.
SURREAL_HTTP_CONNECT_TIMEOUT_SECS 30 A usize The timeout for connecting to HTTP endpoints.
SURREAL_USER_AGENT SurrealDB A string The USER-AGENT string used by HTTP requests.
### HTTP server config
Environment variable Default Allowed values Notes
SURREAL_NET_MAX_CONCURRENT_REQUESTS 1,048,576 A usize How many concurrent network requests can be handled at once
SURREAL_HTTP_MAX_ML_BODY_SIZE 4,294,967,296 (4 GiB) A usize Maximum HTTP body size of the HTTP /ml endpoints. Counted cumulatively across the whole request, not per chunk.
SURREAL_HTTP_MAX_MCP_BODY_SIZE_(since v3.1.0)_ 4,194,304 (4 MiB) A usize Maximum HTTP body size of the HTTP /mcp endpoint. See [Embedded MCP](/docs/build/ai-agents/mcp/embedded.md).
SURREAL_HTTP_MAX_SQL_BODY_SIZE 1,048,576 (1 MiB) A usize Maximum HTTP body size of the HTTP /sql endpoint
SURREAL_HTTP_MAX_GQL_BODY_SIZE_(since v3.2.0)_ 1,048,576 (1 MiB) A usize Maximum HTTP body size of the HTTP /gql endpoint. See GQL via HTTP.
SURREAL_HTTP_MAX_API_BODY_SIZE 4,194,304 (4 MiB) A usize The maximum HTTP body size of the HTTP /api endpoint.
SURREAL_HTTP_MAX_RPC_BODY_SIZE 4,194,304 (4 MiB) A usize Maximum HTTP body size of the HTTP /rpc endpoint.
SURREAL_HTTP_MAX_KEY_BODY_SIZE 16,384 (16 KiB) A usize Maximum HTTP body size of the HTTP /key endpoints
SURREAL_HTTP_MAX_SIGNUP_BODY_SIZE 1024 (1 KiB) A usize Maximum HTTP body size of the HTTP /signup endpoint.
SURREAL_HTTP_MAX_IMPORT_BODY_SIZE 4,294,967,296 (4 GiB) A usize Maximum HTTP body size of the HTTP /import endpoint. Counted cumulatively across the whole request, not per chunk. Also enforced on the gRPC import stream. See [Request size limits](/docs/reference/rest-api/http-protocol.md#request-size-limits).
SURREAL_HTTP_MAX_SIGNIN_BODY_SIZE 1024 (1 KiB) A usize The maximum HTTP body size of the HTTP /signin endpoints
> [!NOTE] > Before SurrealDB 3.3.0, `SURREAL_HTTP_MAX_SIGNUP_BODY_SIZE` and `SURREAL_HTTP_MAX_SIGNIN_BODY_SIZE` were applied to each other's endpoint. Both default to 1 KiB, so no default deployment was affected, but raising one of them had no effect on the endpoint it names and the other endpoint kept returning `413 Payload Too Large`. If you worked around this by tuning the opposite variable, move the value back to the one that matches the endpoint. ### MCP config _(since v3.1.0)_ Used by the built-in [Model Context Protocol](/docs/build/ai-agents/mcp/embedded.md) server (`/mcp` on `surreal start`, `surreal mcp` on stdio). Stdio namespace/database selection uses `SURREAL_MCP_NS` and `SURREAL_MCP_DB` on the [`mcp`](/docs/reference/cli/surrealdb-cli/commands/mcp.md) subcommand.
Environment variable Default Allowed values Notes
SURREAL_MCP_QUERY_TIMEOUT_SECS 60 Seconds (integer); 0 disables Outer timeout on each MCP tool execution.
SURREAL_MCP_MAX_RESULT_BYTES 262,144 (256 KiB) Bytes (integer); 0 disables Maximum serialised tool / resource response size; larger results are truncated with a marker.
SURREAL_MCP_RUN_MAX_ARGS 64 A positive integer Maximum arguments for a single run tool call.
SURREAL_MCP_PARAMS_MAX_KEYS 256 A positive integer Maximum top-level keys in MCP parameter / data objects.
SURREAL_MCP_PARAMS_MAX_QL_BYTES 4,096 (4 KiB) A positive integer; values ≤ 0 fall back to the default Maximum byte length of a single $ql SurrealQL pass-through string inside a *_data payload.
SURREAL_MCP_SCHEMA_RESOURCE_MAX_TABLES 200 A positive integer; values ≤ 0 fall back to the default Maximum tables the database-level schema resource enriches with per-table fields / indexes / events. Tables beyond the cap keep a bare DEFINE TABLE and the body includes a tables_truncated_at marker.
SURREAL_MCP_ALLOWED_HOSTS _(since v3.2.1)_ loopback only (localhost, 127.0.0.1, ::1) Comma-separated exact hostnames Hostnames accepted in the HTTP Host header for /mcp (DNS-rebinding guard). A non-empty list replaces the loopback default, so include localhost yourself if you still need it. Entries without a port match any port. Ignored when SURREAL_MCP_ALLOW_ALL_HOSTS is set.
SURREAL_MCP_ALLOW_ALL_HOSTS _(since v3.2.1)_ false true / 1 to enable Disables the Host-header allowlist (accept any Host). Escape hatch for a trusted proxy or load balancer. Takes precedence over SURREAL_MCP_ALLOWED_HOSTS.
### GQL config _(since v3.2.0)_ Resource limits for [ISO GQL](/docs/learn/querying/gql/overview.md) `MATCH` execution. Errors name the limit when it is exceeded. From **3.3.0**, GQL is enabled by default; on **3.2.x**, enable it with [`--allow-experimental gql`](/docs/reference/cli/surrealdb-cli/commands/start.md#experimental-capabilities).
Environment variable Default Allowed values Notes
SURREAL_GQL_MAX_PATH_ROWS 1,000,000 A usize Per source row, bounds live and emitted rows during variable-length path expansion in a GQL MATCH.
SURREAL_GQL_MAX_JOIN_BUILD_ROWS 1,000,000 A usize Bounds the in-memory build side of hash joins between GQL match patterns (and distinct-operator working sets).
SURREAL_GQL_MAX_OUTPUT_ROWS 1,000,000 A usize Bounds cumulative rows emitted by GQL hash-join operators (including cross joins).
### Limits config
Environment variable Default Allowed values Notes
SURREAL_EXTERNAL_SORTING_BUFFER_LIMIT 50000 A usize The number of result records which will trigger on-disk sorting.
SURREAL_STRING_SIMILARITY_LIMIT 16384 A usize The maximum input string length for similarity/distance functions
SURREAL_GENERATION_ALLOCATION_LIMIT 1,048,576 A usize Limits memory allocation for certain built-in functions (e.g., string::replace) to avoid uncontrolled memory usage. Default is 1,048,576 bytes (computed as 220).
SURREAL_IDIOM_RECURSION_LIMIT 256 A usize The maximum recursive idiom path depth allowed.
SURREAL_MAX_COMPUTATION_DEPTH 120 A usize Specifies how deep recursive computation will go before erroring.
SURREAL_MAX_CONCURRENT_TASKS 64 A usize Specifies how many concurrent jobs can be buffered in the worker channel.
SURREAL_MAX_OBJECT_PARSING_DEPTH 100 A usize Specifies how deep the parser will parse nested objects and arrays in a query.
SURREAL_MAX_ORDER_LIMIT_PRIORITY_QUEUE_SIZE_(since v2.2.0)_ 1000 A usize The maximum size of the priority queue triggering usage of the priority queue for the result collector.
SURREAL_MAX_QUERY_PARSING_DEPTH 20 A usize Specifies how deep the parser will parse recursive queries (queries within queries).
SURREAL_OPERATOR_BUFFER_SIZE 2 A usize The number of batches each operator buffers ahead of downstream demand. Set to 0 to disable operator-level pipeline buffering.
SURREAL_REGEX_SIZE_LIMIT 10,485,760 (10 MiB) A usize Limits the maximum allowed size (in bytes) for regular expressions. This prevents excessive memory consumption when building complex or very large regex patterns.
SURREAL_TRANSACTION_MAX_WRITE_KEYS_(since v3.2.4)_ 0 (disabled) A u64; 0 disables Maximum number of key writes a single statement transaction may buffer before it is aborted and rolled back. Cascaded deletes, full-text index maintenance, graph-edge cleanup, and commit-time changefeed / live-query events all count toward the limit; each range delete counts as one write. Tripping the guard poisons the transaction so an explicit client COMMIT cannot persist a partial statement. Internal maintenance transactions (index builds, compaction, GC) are not bounded. On TiKV, range deletes may expand further inside the storage layer - size distributed clusters with both this limit and SURREAL_TIKV_DELR_MAX_KEYS in mind. Scale / multi-node deployments often use a limit in the 50,000-100,000 range; leave at 0 for typical single-node use.
### Runtime config
Environment variable Default Allowed values Notes
SURREAL_RUNTIME_MAX_BLOCKING_THREADS 512 A usize Number of threads which can be started for blocking operations.
SURREAL_RUNTIME_STACK_SIZE 10,485,760 (10 MiB) A usize Runtime thread memory stack size. Default stack size is doubled if compiled from source in Debug mode.
SURREAL_RUNTIME_WORKER_THREADS Number of CPU cores (minimum 4) A usize Number of runtime worker threads used to start.
### Scripting config
Environment variable Default Allowed values Notes
SURREAL_SCRIPTING_MAX_STACK_SIZE 262_144 (256 KiB) A usize Maximum stack size of the JavaScript function runtime.
SURREAL_SCRIPTING_MAX_MEMORY_LIMIT 2,097,152 (2 MiB) A usize Maximum memory limit of the JavaScript function runtime.
SURREAL_SCRIPTING_MAX_TIME_LIMIT 5000 (5000 milliseconds or 5 seconds) A usize Maximum allowed time in milliseconds that a JavaScript function is allowed to run for.
### Security config
Environment variable Default Allowed values Notes
SURREAL_INSECURE_FORWARD_ACCESS_ERRORS false true, false Forward all signup/signin/authenticate query errors to a client performing authentication. Do not use in production.
### Surrealism config
Environment variable Default Allowed values Notes
SURREAL_LAZY_SURREALISM_(since v3.1.0)_ false true, false Whether to lazy-load Surrealism modules instead of eagerly compiling them at server startup.
SURREAL_SURREALISM_CACHE_SIZE_(since v3.0.0)_ 100 A usize The number of surrealism modules which can be cached across transactions.
SURREAL_SURREALISM_MAX_POOL_SIZE_(since v3.0.0)_ 8 A usize Per-module controller pool size ceiling for Surrealism WASM modules.
SURREAL_SURREALISM_MAX_MEMORY_(since v3.0.0)_ None (unlimited) A usize Per-module WASM linear memory ceiling in bytes.
SURREAL_SURREALISM_MAX_EXECUTION_TIME_(since v3.0.0)_ None (unlimited) A u64 (milliseconds) Per-invocation execution time ceiling for Surrealism WASM modules.
SURREAL_SURREALISM_MAX_KV_ENTRIES_(since v3.0.0)_ None (unlimited) A usize Per-module KV store entry count ceiling.
SURREAL_SURREALISM_MAX_KV_VALUE_BYTES_(since v3.0.0)_ None (unlimited) A usize Per-module KV store maximum value size in bytes.
SURREAL_SURREALISM_LOG_LEVEL_(since v3.1.0)_ debug none, full, error, warn, info, debug, trace Controls the tracing level at which Surrealism module stdout is emitted.
### Telemetry config
Environment variable Default Allowed values Notes
SURREAL_TELEMETRY_DISABLE_METRICS false true, false Whether to disable sending metrics to the GRPC OTEL collector.
SURREAL_TELEMETRY_DISABLE_TRACING false true, false Whether to disable sending traces to the GRPC OTEL collector.
SURREAL_TELEMETRY_NAMESPACE none A string If set then use this as value for the namespace label when sending telemetry
SURREAL_TELEMETRY_PROVIDER none otlp If set to "otlp" then telemetry is sent to the GRPC OTEL collector.
SURREAL_TOKIO_CONSOLE_ENABLED_(since v3.0.0)_ false true, false Whether to enable [tokio console](https://github.com/tokio-rs/console).
SURREAL_TOKIO_CONSOLE_RETENTION_(since v3.0.0)_ 60 A usize How long, in seconds, to retain data for completed events.
SURREAL_TOKIO_CONSOLE_SOCKET_ADDR_(since v3.0.0)_ none String to a socket address The socket address that Tokio Console will bind to.
### WebSocket config
Environment variable Default Allowed values Notes
SURREAL_WEBSOCKET_MAX_MESSAGE_SIZE 134,217,728 (128 MiB) A usize The maximum WebSocket message size.
SURREAL_WEBSOCKET_MAX_WRITE_BUFFER_SIZE Greatest possible usize value A usize The maximum write buffer size before backpressure is applied.
SURREAL_WEBSOCKET_READ_BUFFER_SIZE 131,072 (128 KiB) A usize The size of the read buffer for WebSocket connections. This controls how much data can be buffered when reading from WebSocket connections. Larger values can improve performance for high-throughput connections but consume more memory per connection.
SURREAL_WEBSOCKET_WRITE_BUFFER_SIZE 131,072 (128 KiB) A usize The size of the write buffer for WebSocket connections. This controls how much data can be buffered when writing to WebSocket connections. Larger values can improve performance for high-throughput connections but consume more memory per connection.
SURREAL_WEBSOCKET_RESPONSE_BUFFER_SIZE 0 A usize How many responses can be buffered when delivering to the client.
SURREAL_WEBSOCKET_RESPONSE_CHANNEL_SIZE 100 A usize Number of messages that can be queued for sending via WebSocket.
SURREAL_WEBSOCKET_RESPONSE_FLUSH_PERIOD 3 A usize How often (in milliseconds) any buffered responses are flushed to the WebSocket client.
SURREAL_MAX_TRANSACTIONS_PER_CONNECTION_(since v3.2.2)_ 64 A usize Maximum concurrently open client-managed transactions (begin RPC) on a WebSocket connection's implicit default session. Further begin calls return Too many open transactions until a slot is freed by commit, cancel, reset, or disconnect. Does not apply to attached sessions (see SURREAL_MAX_TRANSACTIONS_PER_SESSION).
SURREAL_MAX_TRANSACTIONS_PER_SESSION_(since v3.2.2)_ 64 A usize Maximum concurrently open client-managed transactions within a single attached WebSocket session. Counted per session and independent of the connection default-session limit. Detaching or resetting a session cancels its open transactions and frees their slots.
### Operator and internal config _(since v3.2.0)_ These settings are for operators, benchmarks, and advanced debugging - not typical application configuration. They are documented so core contributors and self-hosted deployments can find configuration options that already exist in the engine. Changing them can affect performance, reproducibility, or live-query behaviour; leave defaults in place unless you have a specific reason to tune them.
Environment variable Default Allowed values Notes
SURREAL_RAND_SEED none (non-deterministic) A u64 Seeds the engine-wide RNG for reproducible runs in benchmarks and tests. Do not use in production.
SURREAL_LIVE_QUERY_ENGINE inline inline, router Selects the live-query execution engine. inline is the historical behaviour; router decouples write cost from subscriber count (experimental rollout).
SURREAL_LIVE_QUERY_RETENTION 1h A duration How long the router engine retains live-query event history for subscriber resume. Only applies when SURREAL_LIVE_QUERY_ENGINE=router.
SURREAL_HNSW_BUILD_SEED none A u64 Seeds HNSW index construction for reproducible graph layouts in benchmarks. Do not use in production.
### Other environment variables
Environment variable Default Allowed values Notes
SURREAL_BUILD_METADATA Automatically populated A string The version identifier of this build. Defaults to the CARGO_PKG_VERSION environment variable if not specified.
SURREAL_DATASTORE_AOL_(since v3.0.0)_ never never|sync|async Append-only log mode. Only used by the memory engine.
SURREAL_DATASTORE_PERSIST_(since v3.0.0)_ none String to a file path Filesystem path for persistence. Only used by the memory engine.
SURREAL_DATASTORE_RETENTION_(since v3.0.0)_ 0 (unlimited) A duration Version retention period as a duration string. Used by memory and surrealkv engines.
SURREAL_DATASTORE_SNAPSHOT_(since v3.0.0)_ never never|duration Snapshot interval. Only used by the memory engine.
SURREAL_DATASTORE_SYNC_DATA_(since v3.0.0)_ every never|every|duration The sync mode for the database. Used by memory, rocksdb, and surrealkv engines.
SURREAL_DATASTORE_VERSIONED_(since v3.0.0)_ false true|false|0|1 Whether MVCC versioning is enabled. Used by memory and surrealkv engines.
SURREAL_MEMORY_THRESHOLD 0 A usize or suffixed integer Configuring the memory threshold which can be used across the programme to check if the amount of memory available to the programme is lower than required. The value can be specified as bytes (b, or without any suffix), kibibytes (k, kb, or kib), mebibytes (m, mb, or mib), or gibibytes (g, gb, or gib). If the environment variable is not specified, then the threshold is not used, and no memory limit is enabled.
SURREAL_REGEX_CACHE_SIZE 1000 A usize The number of computed regexes which can be cached in the engine.
## Command environment variables Many of the arguments passed into [the CLI](/docs/reference/cli/surrealdb-cli/commands/start.md) can be set using the above environment variables instead. As each of these environment variables correspond to a flag or a required argument passed into a command, it is good practice to put together a command that matches the environment variables you wish to set. Once the database server conforms to your expected behaviour, you can then pull out the values passed into each flag for your environment variables. For example, take the following command to start the database. ```bash surreal start --user root --pass secret --allow-net --deny-funcs "crypto::md5, http::post, http::delete" ``` If we now wanted to use environment variables instead of the `--allow-net` and `--deny-funcs` flags, we would use the `SURREAL_CAPS_ALLOW_NET` and `SURREAL_CAPS_DENY_FUNC` environment variables. As the `--allow-net` flag was passed in without a following value, the same will be the case with the `SURREAL_CAPS_ALLOW_NET` environment variable, becoming `SURREAL_CAPS_ALLOW_NET=`. The `--deny-funcs` flag can also be used on its own to deny execution of all functions, but in this case is followed by a string to indicate which exact functions are not allowed to be executed. As such, the `SURREAL_CAPS_DENY_FUNC` environment variable must also be followed by a string, becoming `SURREAL_CAPS_DENY_FUNC="crypto::md5, http::post, http::delete"`. The command would then look like the following: **Bash** ```bash SURREAL_CAPS_ALLOW_NET SURREAL_CAPS_DENY_FUNC="crypto::md5, http::post, http::delete" surreal start --user root --pass secret ``` **PowerShell** ```powershell $env:SURREAL_CAPS_ALLOW_NET $env:SURREAL_CAPS_DENY_FUNC="crypto::md5, http::post, http::delete" surreal start --user root --pass secret ``` A command environment variable that takes a boolean will be set to true if the flag is present, and following it with `true` will cause an error. For example, the `SURREAL_CAPS_ALLOW_ALL` environment variable is used to set whether to allow all capabilities such as scripting and allowing network access. The flag `--allow-all` is all that is needed to set to `true`. But as an environment variable, the value `true` must be included to override its default `false` value. ```bash title="SURREAL_CAPS_ALLOW_ALL example" # set to default false surreal start # Same, but implicitly shown SURREAL_CAPS_ALLOW_ALL=false surreal start # Set to true SURREAL_CAPS_ALLOW_ALL=true surreal start # Set to true surreal start --allow-all # Error: only --allow-all needed to set to true surreal start --allow-all true ```
Environment variable Command arg For command(s) Default Allowed values Details
SURREAL_ASYNC_EVENT_PROCESSING_INTERVAL_(since v3.0.0)_ async-event-processing-interval `start` 5s A duration The interval at which to process async events.
SURREAL_AUTH_LEVEL auth-level `export`, `import`, `sql` root root, namespace, ns, database, db Authentication level to use when connecting.
SURREAL_BIND bind `start` 127.0.0.1:8000 String to an address The hostname or IP address(es) to listen for connections on.
SURREAL_POSTGRES_BIND postgres-bind `start` (disabled) String to an address The hostname or IP address to listen for Postgres wire protocol connections on.
SURREAL_CAPS_ALLOW_ALL allow-all `start` false true, false Allow all capabilities.
SURREAL_CAPS_ALLOW_ARBITRARY_QUERY allow-arbitrary-query `start` none guest, record, system (comma-separated) Allows arbitrary queries to be used by user groups except when specifically denied. Alternatively, you can provide a comma-separated list of user groups to allow specifically denied user groups to prevail over any other allowed user group.
SURREAL_CAPS_ALLOW_EVAL_QUERY_(since v3.2.0)_ allow-eval-query `start`, `sql` none (denied for all subjects) guest, record, system (comma-separated) Allow eval::surql and eval::gql for listed subject groups. Not enabled by --allow-all. Still subject to arbitrary-query restrictions - --deny-arbitrary-query blocks eval for that subject even when eval is allowed here. For remote clients, set on the start process only. See Capabilities and remote connections.
SURREAL_CAPS_ALLOW_EXPERIMENTAL allow-experimental `start`, `sql` none files, surrealism (comma-separated; legacy gql accepted but unused from 3.3.0) Allow execution of experimental features. For remote clients, set on the start process. On surreal sql, affects embedded engines and REPL parse validation only. See experimental capabilities. From 3.3.0, ISO GQL is on by default and does not need this variable.
SURREAL_CAPS_ALLOW_FUNC allow-funcs `start` all functions allowed Empty, *, or comma-separated function paths Allow execution of all functions except for functions that are specifically denied. Set to an empty value or * to allow all functions. Use a comma-separated list (for example, array,string::len,http::get) to allow specific function families or names. Values such as true are not valid. The environment variable name is singular (FUNC), matching the --allow-funcs flag.
SURREAL_CAPS_ALLOW_GUESTS allow-guests `start` true true, false Allow guest users to execute queries.
SURREAL_CAPS_ALLOW_NET allow-net `start` none Comma-separated list of paths Allow all or certain outbound network access.
SURREAL_CAPS_ALLOW_SCRIPT allow-scripting `start` true true, false Allow execution of embedded scripting functions.
SURREAL_CAPS_ALLOW_INSECURE_STORABLE_CLOSURES_(since v2.5.0)_ allow-insecure-storable-closures `start` false true, false Takes a boolean. Prevents closures from being stored, which eliminates a potential attack surface. For version 2.5.0, this can still be allowed by using this capability.
SURREAL_CAPS_DENY_ALL deny-all `start` false true, false Deny all capabilities.
SURREAL_CAPS_DENY_EVAL_QUERY_(since v3.2.0)_ deny-eval-query `start`, `sql` none guest, record, system (comma-separated) Deny eval::surql and eval::gql for listed subject groups. Deny prevails over allow at the same specificity. For remote clients, set on the start process.
SURREAL_CAPS_DENY_FUNC deny-funcs `start` false true, false, comma-separated list Deny execution of all or certain functions.
SURREAL_CAPS_DENY_GUESTS deny-guests `start` true true, false Deny guest users from executing queries.
SURREAL_CAPS_DENY_NET deny-net `start` true true, false, comma-separated list Deny all or certain outbound access paths.
SURREAL_CAPS_DENY_SCRIPT deny-scripting `start` true true, false Deny execution of embedded scripting functions.
SURREAL_CHANGEFEED_GC_INTERVAL changefeed-gc-interval `start` 30s A duration The interval at which to perform changefeed garbage collection.
SURREAL_CLIENT_IP client-ip `start` none none, socket, CF-Connecting-IP, Fly-Client-IP, True-Client-IP, X-Real-IP, X-Forwarded-For, Forwarded The method of detecting the client's IP address. _(since v3.1.0)_ Forwarded parses the RFC 7239 Forwarded header (for= parameter).
SURREAL_DATABASE database `sql` main A string The database selected when starting the REPL.
SURREAL_DATABASE database `export`, `import` none A string The database selected for the import or export.
SURREAL_DEFAULT_DATABASE_(since v3.0.0)_ default-database `start` main A string The default database to use when starting a SurrealDB instance.
SURREAL_DEFAULT_NAMESPACE_(since v3.0.0)_ default-namespace `start` main A string The default namespace to use when starting a SurrealDB instance.
SURREAL_DURABLE_SESSIONS_(since v3.2.2)_ durable-sessions `start` false true, false Persist client-attached HTTP RPC sessions in the datastore so they survive restarts and can be resumed on any node sharing the storage. Off by default. WebSocket sessions are not durable. The persisted copy includes authentication state and is stored unencrypted. See Durable HTTP RPC sessions.
SURREAL_DURABLE_SESSION_GC_INTERVAL_(since v3.2.2)_ durable-session-gc-interval `start` 60s A duration; 0 disables the background sweep How often expired durable HTTP RPC sessions are purged. Lazy expiry on load still applies when the sweep is disabled. Only meaningful when durable sessions are enabled.
SURREAL_DURABLE_SESSION_TTL_(since v3.2.2)_ durable-session-ttl `start` 24h A duration greater than zero Idle lifetime of a persisted HTTP RPC session; each use refreshes the expiry (sliding TTL). Must be greater than zero when durable sessions are enabled.
SURREAL_HIDE_WELCOME hide-welcome `sql` false true, false Whether to show the welcome message when starting the REPL.
SURREAL_IMPORT_FILE import-file `start` none A file path Path to a SurrealQL file that will be imported when starting the server.
SURREAL_INDEX_COMPACTION_INTERVAL_(since v3.0.0)_ index-compaction-interval `start` 5s A duration The interval at which to compact queued index updates. Writes to a full-text, count, or vector index enqueue pending updates that a background task folds into the index; this controls how often that task runs. One node in a cluster performs the work for the whole cluster. Lengthening the interval allows the pending backlog to grow, which increases the work each subsequent query must do to read through it.
SURREAL_KEY key `start` none A string 16, 24, or 32 bytes long Encryption key to use for on-disk encryption. Not currently in use.
SURREAL_KVS_CA kvs-ca `start` none String to a path Path to the CA file used when connecting to the remote KV store.
SURREAL_KVS_CRT kvs-crt `start` none String to a path Path to the certificate file used when connecting to the remote KV store.
SURREAL_KVS_KEY kvs-key `start` none String to a path Path to the private key file used when connecting to the remote KV store.
SURREAL_LAZY_SURREALISM_(since v3.1.0)_ lazy-surrealism `start` false true, false Whether to lazy-load Surrealism modules instead of eagerly compiling them at server startup.
SURREAL_LOG log `start`, `fix` info none, full, error, warn, info, debug, trace The logging level for the database server.
SURREAL_LOG_FILE_ENABLED_(since v2.4.0)_ log-file-enabled `start` false true, false Toggles file output.
SURREAL_LOG_FILE_FORMAT_(since v2.4.0)_ log-file-format `start` none text, json The format for log file output.
SURREAL_LOG_FILE_LEVEL_(since v2.4.0)_ log-file-level `start` none none, full, error, warn, info, debug, trace Override the logging level for file output
SURREAL_LOG_FILE_NAME_(since v2.4.0)_ log-file-name `start` surrealdb.log String to a file Filename for logs (default: `surrealdb.log`)
SURREAL_LOG_FILE_PATH_(since v2.4.0)_ log-file-path `start` logs String to a path Sets the directory for logs
SURREAL_LOG_FILE_ROTATION_(since v2.4.0)_ log-file-rotation `start` daily daily, hourly, never Sets the rotation duration for logs.
SURREAL_LOG_FORMAT_(since v2.4.0)_ log-format `start` text text, json Sets the format for logs.
SURREAL_LOG_OTEL_LEVEL
_(since v2.4.0)_		 log-otel-level `start` SURREAL_LOG logging level none, full, error, warn, info, debug, trace Override the logging level for OpenTelemetry
SURREAL_LOG_SOCKET_(since v3.0.0)_ log-socket `start` none String to a host:port Send logs to the specified host:port
SURREAL_LOG_SOCKET_FORMAT_(since v3.0.0)_ log-socket-format `start` text text, json Set the format of the logs to the socket.
SURREAL_LOG_SOCKET_LEVEL_(since v3.0.0)_ log-socket-level `start` SURREAL_LOG logging level none, full, error, warn, info, debug, trace Override the logging level for socket logs. Possible values: none, full, error, warn, info, debug, trace
SURREAL_NAME name `ml export` none A string The name of the model.
SURREAL_NAMESPACE namespace `sql` main A string The namespace to connect to via the REPL.
SURREAL_NAMESPACE namespace `export`, `import` none A string The namespace selected for the import/export operation.
SURREAL_NO_BANNER no-banner `start` false true, false Whether to hide the startup banner.
SURREAL_NO_DEFAULTS_(since v3.0.0)_ no-defaults `start` false true, false Whether to disable default namespace and database creation. Conflicts with SURREAL_DEFAULT_DATABASE and SURREAL_DEFAULT_NAMESPACE, which set a default value for namespace and database for a new instance.
SURREAL_NO_IDENTIFICATION_HEADERS no-identification-headers `start` false true, false Whether to suppress the server name and version headers.
SURREAL_NODE_MEMBERSHIP_CHECK_INTERVAL node-membership-check-interval `start` 15s A duration The interval at which to process and archive inactive nodes.
SURREAL_NODE_MEMBERSHIP_CLEANUP_INTERVAL node-membership-cleanup-interval `start` 300s A duration The interval at which to process and cleanup archived nodes.
SURREAL_NODE_MEMBERSHIP_REFRESH_INTERVAL node-membership-refresh-interval `start` 3s A duration The interval at which to refresh node registration information.
SURREAL_PASS pass `export`, `import`, `sql`, `start` none A string Database authentication password to use when connecting.
SURREAL_PATH path `fix`, `start` memory A string Database path used for storing data. As a required argument (albeit with a default), it is not passed in via `--path`.
SURREAL_PLANNER_STRATEGY_(since v3.0.0)_ planner-strategy `start` best-effort best-effort|compute-only|all-read-only Which strategy to use with the new query planner introduced in SurrealDB 3.0. The default setting uses the new planner for read-only statements, falling back to the previous compute planner on unimplemented paths. The new planner can be skipped entirely by using compute-only.
SURREAL_QUERY_TIMEOUT query-timeout `start` none A duration The maximum duration that a set of statements can run for.
SURREAL_READINESS_HEARTBEAT_MAX_AGE_(since v3.3.0)_ readiness-heartbeat-max-age `start` Three times node-membership-refresh-interval (9s) A duration How stale this node's cluster heartbeat may get before /ready reports the node unhealthy. When unset, it is derived as three times node-membership-refresh-interval. Startup warns if the configured value reaches 30s - the interval after which peers archive an unresponsive node and collect its live queries - because a node reported ready after the cluster has written it off keeps taking traffic. The value is not clamped.
SURREAL_RECLAIM_INTERVAL_(since v3.2.0)_ reclaim-interval `start` 60s A duration How often the background reaper scans for tombstoned namespace, database, and index data to physically delete after a REMOVE statement.
SURREAL_RECLAIM_GRACE_(since v3.2.0)_ reclaim-grace `start` 10m A duration Minimum age a removed namespace, database, or index must reach before its data is reclaimed. The effective grace is the maximum of this value and --tikv-gc-lifetime on TiKV backends.
SURREAL_SLOW_QUERY_LOG_THRESHOLD
_(since v2.3.8)_		 slow-log-threshold `start` none A duration A duration specifying the minimum execution time after which a log is made to indicate a slow query
SURREAL_SLOW_QUERY_LOG_PARAM_ALLOW
slow-log-param-allow _(since v2.3.9)_		 slow-log-param-allow `start` none Comma-separated strings A comma-separated list of parameter names to include in slow query logs.
SURREAL_SLOW_QUERY_LOG_PARAM_DENY_(since v2.3.9)_ slow-log-param-deny `start` none Comma-separated strings A comma-separated list of parameter names to omit from slow query logs.
SURREAL_STRICT strict `start` false true, false Whether strict mode is enabled on this database instance. Ignored since SurrealDB 3.0 after which strictness is defined [per database](/docs/reference/query-language/statements/define/database.md#defining-a-strict-database) instead of instance.
SURREAL_TEMPORARY_DIRECTORY temporary-directory `start` none String to a directory Sets the directory for storing temporary database files
SURREAL_TOKEN token `export`, `import`, `sql` none A string Authentication token in JWT format to use when connecting.
SURREAL_TRANSACTION_TIMEOUT transaction-timeout `start` none A duration The maximum duration that any single transaction can run for.
SURREAL_UNAUTHENTICATED unauthenticated `start` false true, false Whether to allow unauthenticated access.
SURREAL_USER user `export`, `import`, `sql`, start none A string Database authentication username to use when connecting.
SURREAL_VERSION version `ml export` none A string The version of the ML model.
SURREAL_WEB_CRT web-crt `start` none String to a path Path to the certificate file for encrypted client connections.
SURREAL_WEB_KEY web-key `start` none String to a path Path to the private key file for encrypted client connections.
## Storage backend environment variables These environment variables are used to configure the storage backend for SurrealDB. ### RocksDB environment variables Many RocksDB environment variables pertain to memory use. The default configuration results in the following rough estimates of RocksDB memory use on different instances: | Instance memory size | Estimate | ------------- |:-------------:| | 512 MiB | ~ 80MiB | | 1 GiB | ~ 80MiB | 2 GiB | ~ 640MiB | 4 GiB | ~ 1.25GiB | 8 GiB | ~ 3.25GiB | 24 GiB | ~ 12GiB | 128 GiB | ~ 67GiB The available environment variables for configuring a RocksDB instance are:
Environment variable Default Allowed values Notes
SURREAL_ROCKSDB_BACKGROUND_FLUSH true false, true Whether to enable background WAL file flushing.
SURREAL_ROCKSDB_BACKGROUND_FLUSH_INTERVAL 200 (milliseconds) A usize The interval in milliseconds between background flushes.
SURREAL_ROCKSDB_BLOB_COMPRESSION_TYPE snappy none, snappy, lz4, zstd Compression type used for blob files.
SURREAL_ROCKSDB_BLOB_FILE_SIZE 268,435,456 (256 MiB) A usize The target blob file size for RocksDB.
SURREAL_ROCKSDB_ENABLE_BLOB_GC true true, false Whether to enable blob garbage collection for RocksDB.
SURREAL_ROCKSDB_BLOB_GC_AGE_CUTOFF 0.5 Float between 0 and 1 Fractional age cutoff for blob GC.
SURREAL_ROCKSDB_BLOB_GC_FORCE_THRESHOLD 0.5 Float between 0 and 1 Discardable ratio threshold to force GC.
SURREAL_ROCKSDB_BLOB_COMPACTION_READAHEAD_SIZE 0 A usize Readahead size for blob compaction/GC.
SURREAL_ROCKSDB_BLOCK_CACHE_SIZE Dynamically calculated via greater of ((system memory / 2) - 1 GiB) and 16MiB A usize RocksDB block cache size in bytes
SURREAL_ROCKSDB_BLOCK_SIZE 65,536 (64 KiB) A usize The size of each uncompressed data block in bytes.
SURREAL_ROCKSDB_COMPACTION_READAHEAD_SIZE 4 MiB (systems under 4 GiB), 8 MiB (up to 16 GiB), 16 MiB (others) A usize The readahead buffer size used during compaction.
SURREAL_ROCKSDB_COMPACTION_STYLE level level, universal Use to specify the database compaction style.
SURREAL_ROCKSDB_DELETION_FACTORY_DELETE_COUNT 50 A usize The number of deletions to track in the window.
SURREAL_ROCKSDB_DELETION_FACTORY_RATIO 0.5 A float The ratio of deletions to track in the window.
SURREAL_ROCKSDB_DELETION_FACTORY_WINDOW_SIZE 1000 A usize The size of the window used to track deletions.
SURREAL_ROCKSDB_ENABLE_BLOB_FILES true true, false Whether to enable separate key and value file storage.
SURREAL_ROCKSDB_ENABLE_PIPELINED_WRITES true true, false Whether to use separate queues for WAL writes and memtable writes.
SURREAL_ROCKSDB_GROUPED_COMMIT true true, false Whether to enable grouped commit when sync is enabled. When enabled, multiple transaction commits are batched together and flushed to disk with a single fsync operation, improving throughput. When disabled, each transaction is committed and synced individually, which may provide lower latency for single transactions at the cost of reduced throughput under high load. Only used when SURREAL_SYNC_DATA is enabled and SURREAL_ROCKSDB_BACKGROUND_FLUSH is disabled.
SURREAL_ROCKSDB_GROUPED_COMMIT_MAX_BATCH_SIZE 4096 A usize The maximum number of transactions in a single grouped commit batch. Used to prevent unbounded memory growth while still allowing large batches for efficiency. Larger batches improve throughput but increase memory usage and commit latency.
SURREAL_ROCKSDB_GROUPED_COMMIT_TIMEOUT 5ms A duration The maximum wait time in nanosecond before forcing a grouped commit. Used to ensure that transactions do not wait indefinitely when concurrency is low, and to balance between transaction latency and write throughput.
SURREAL_ROCKSDB_GROUPED_COMMIT_WAIT_THRESHOLD 12 A usize Threshold for deciding whether to wait for more transactions. If the current batch size is greater or equal to this threshold (and below ROCKSDB_GROUPED_COMMIT_MAX_BATCH_SIZE), then the coordinator will wait up to ROCKSDB_GROUPED_COMMIT_TIMEOUT to collect more transactions. Smaller batches are flushed immediately to preserve low latency.
SURREAL_ROCKSDB_FILE_COMPACTION_TRIGGER 4 A usize The number of files needed to trigger level 0 compaction.
SURREAL_ROCKSDB_JOBS_COUNT Number of CPUs * 2 A usize The maximum number of threads to use for flushing and compaction.
SURREAL_ROCKSDB_KEEP_LOG_FILE_NUM 10 A usize The maximum number of information log files to keep.
SURREAL_ROCKSDB_MAX_CONCURRENT_SUBCOMPACTIONS 4 A usize The maximum number threads which will perform compactions.
SURREAL_ROCKSDB_MAX_OPEN_FILES 1024 A usize The maximum number of open files which can be opened by RocksDB.
SURREAL_ROCKSDB_MAX_WRITE_BUFFER_NUMBER 2 (systems under 4 GiB), 4 (up to 16 GiB), 8 (up to 64 GiB), 32 (others) A usize The maximum number of write buffers which can be used.
SURREAL_ROCKSDB_MIN_BLOB_SIZE 4096 A usize The minimum size in bytes of a value for it to be stored in blob files.
SURREAL_ROCKSDB_MIN_WRITE_BUFFER_NUMBER_TO_MERGE 2 A usize The minimum number of write buffers to merge before writing to disk.
SURREAL_ROCKSDB_SST_MAX_ALLOWED_SPACE_USAGE 0 A usize The maximum allowed space usage for SST files in bytes. The default of 0 means unlimited and disables space monitoring. When this limit is reached, the datastore enters read-and-deletion-only mode, where only read and delete operations are allowed. This allows gradual space recovery through data deletion.
SURREAL_ROCKSDB_STORAGE_LOG_LEVEL warn none, full, error, warn, info, debug, trace The information log level of the RocksDB library.
SURREAL_ROCKSDB_TARGET_FILE_SIZE_BASE 67,108,864 (64 MiB) - The target file size for compaction in bytes.
SURREAL_ROCKSDB_TARGET_FILE_SIZE_MULTIPLIER 2 A usize The target file size multiplier for each compaction level.
SURREAL_ROCKSDB_THREAD_COUNT Number of CPUs on machine A usize The number of threads to start for flushing and compaction.
SURREAL_ROCKSDB_WAL_SIZE_LIMIT 0 A usize The write-ahead-log size limit in MiB.
SURREAL_ROCKSDB_WRITE_BUFFER_SIZE 32 MiB (systems under 1 GiB), 64 MiB (up to 16 GiB), 128 MiB (others) A usize The amount of data each write buffer can build up in memory.
SURREAL_SYNC_DATA true true, false Whether to sync writes to disk before acknowledgement.
### SurrealKV environment variables
Environment variable Default Allowed values Notes
SURREAL_SURREALKV_ENABLE_VLOG true true, false Whether to enable value log separation.
SURREAL_SURREALKV_VERSIONED_INDEX false true, false Whether to enable versioned index. Only applies when versioning is enabled.
SURREAL_SURREALKV_BLOCK_SIZE 65_536 (64 KiB) A usize The block size in bytes.
SURREAL_SURREALKV_VLOG_MAX_FILE_SIZE 64 MiB (systems under 4 GiB), 128 MiB (up to 16 GiB), 256 MiB (up to 64 GiB), 512 MiB (others) A usize The readahead buffer size used during compaction.
SURREAL_SURREALKV_VLOG_THRESHOLD 4096 (4 KiB) A usize The value log threshold in bytes. Values larger than this are stored in the value log.
SURREAL_SURREALKV_BLOCK_CACHE_CAPACITY Dynamically calculated via greater of ((system memory / 2) - 1 GiB) and 16MiB A usize The maximum log file size in bytes.
SURREAL_SURREALKV_GROUPED_COMMIT_TIMEOUT 5ms A duration in nanoseconds The maximum wait time in nanoseconds before forcing a grouped commit. Ensures that transactions do not wait indefinitely under low concurrency and balances commit latency against write throughput.
SURREAL_SURREALKV_GROUPED_COMMIT_WAIT_THRESHOLD 12 A usize Threshold for deciding whether to wait for more transactions. If the current batch size is greater or equal to this threshold (and below SURREAL_SURREALKV_GROUPED_COMMIT_MAX_BATCH_SIZE), then the coordinator will wait up to SURREAL_SURREALKV_GROUPED_COMMIT_TIMEOUT to collect more transactions. Smaller batches are flushed immediately to preserve low latency.
SURREAL_SURREALKV_GROUPED_COMMIT_MAX_BATCH_SIZE 4096 A usize The maximum number of transactions in a single grouped commit batch. This prevents unbounded memory growth while still allowing large batches for efficiency. Larger batches improve throughput but increase memory usage and commit latency.
### TiKV environment variables > [!IMPORTANT] > These variables apply when SurrealDB is started with a `tikv://` endpoint for **local Community experimentation**. They are not the configuration surface for production multi-node HA. Prefer a managed cluster on [SurrealDB Cloud Scale](https://surrealdb.com/pricing/scale) or a self-hosted cluster with [SurrealDB Enterprise](https://surrealdb.com/enterprise). See [Run a multi-node cluster](/docs/running/multi-node.md).
Environment variable Default Allowed values Notes
SURREAL_TIKV_API_VERSION 1 A u8 Which TiKV cluster API version to use.
SURREAL_TIKV_ASYNC_COMMIT true true, false Whether to use asynchronous transactions.
SURREAL_TIKV_KEYSPACE none A string A string specifying the keyspace identifier for data isolation.
SURREAL_TIKV_GRPC_MAX_DECODING_MESSAGE_SIZE 4,194,304 (4 MiB) A usize Sets the maximum decoding size of a gRPC message.
SURREAL_TIKV_ONE_PHASE_COMMIT true true, false Whether to use one-phase transaction commit.
SURREAL_TIKV_REQUEST_TIMEOUT 10 A usize The duration in seconds for requests before they time out.
### FoundationDB environment variables > [!WARNING] > FoundationDB support is deprecated in SurrealDB `3.0`. Please plan to migrate to a supported storage backend.
Environment variable Default value Notes
SURREAL_FOUNDATIONDB_TRANSACTION_MAX_RETRY_DELAY 500 The maximum delay between transaction retries in milliseconds.
SURREAL_FOUNDATIONDB_TRANSACTION_RETRY_LIMIT 5 The maximum number of times a transaction can be retried.
SURREAL_FOUNDATIONDB_TRANSACTION_TIMEOUT 5000 The maximum transaction timeout in milliseconds.
## SurrealDB Cloud environment variables Instances on SurrealDB Cloud are not started with a CLI command or environment variables. Instead, they can be set from [SurrealDB Studio](/docs/manage/instances/configure.md) or with [`surrealctl`](/docs/reference/cli/surrealctl/overview.md).