--- title: "Extensions | SurrealDB" description: "Run WebAssembly plugins inside SurrealDB. Write functions in Rust, compile to WASM, and execute with full query engine access. No microservices, no cold starts." url: https://surrealdb.com/surrealdb/extensions --- # Extensions [Get started](https://studio.surrealdb.com/current/instances/deploy) [Read the docs](https://surrealdb.com/docs/learn/extensions) **Rust.** Write your functions in Rust, with its types and tooling. **WebAssembly.** Compile once and run inside the engine, sandboxed. **Query access.** Full access to your data from within the function. 1. ![Babcock](https://surrealdb.com/assets/static/babcock.lo4rnVg1.svg) 2. ![ING](https://surrealdb.com/assets/static/ing.X3I6S3_V.svg) 3. ![British Airways](https://surrealdb.com/assets/static/british-airways.KEsZiwV-.svg) 4. ![Nvidia](https://surrealdb.com/assets/static/nvidia.DaIEuMil.svg) 5. ![Apple](https://surrealdb.com/assets/static/apple.D5pq4flY.svg) 6. ![SpaceX](https://surrealdb.com/assets/static/spacex.CQJEk-IL.svg) 7. ![Samsung](https://surrealdb.com/assets/static/samsung.CH-vQgnb.svg) 8. ![adidas](https://surrealdb.com/assets/static/adidas.DdTC5qhk.svg) 9. ![Tencent](https://surrealdb.com/assets/static/tencent.paQmLxyy.svg) 10. ![Alibaba](https://surrealdb.com/assets/static/alibaba.B16idgfM.svg) 11. ![PolyAI](https://surrealdb.com/assets/static/poly-ai.c3w_fAg6.svg) 12. ![Later](https://surrealdb.com/assets/static/later.Ds736jFO.svg) 13. ![Verizon](https://surrealdb.com/assets/static/verizon.BI7CajdX.svg) 14. ![Liberty Mutual](https://surrealdb.com/assets/static/liberty-mutual.B7qOU1pd.svg) 15. ![Walmart](https://surrealdb.com/assets/static/walmart.BjDg_Sr8.svg) 16. ![Carrier](https://surrealdb.com/assets/static/carrier.D21gC6NX.svg) 17. ![Saks Fifth Avenue](https://surrealdb.com/assets/static/saks-fifth-avenue.COIDpLSb.svg) 18. ![San Francisco Compute Company](https://surrealdb.com/assets/static/sfcc.B7jlImq4.svg) 19. ![Shield AI](https://surrealdb.com/assets/static/shield-ai.pINZ0KJr.svg) 20. ![Wix](https://surrealdb.com/assets/static/wix.DvHhmoBi.svg) ## Run extensions inside SurrealDB. A programmable data and logic layer for agentic and AI-heavy workloads. [Read the docs](https://surrealdb.com/docs/learn/extensions) ### [AI-ready by design](https://surrealdb.com/docs/learn/extensions) Call LLMs, embedding models or GPU inference next to the data and write the result back in the same statement. Explore extensions ### [Near-native performance](https://surrealdb.com/docs/surrealdb/extensions/plugins) WebAssembly runs close to the data inside a sandbox: compute beside the records, and nothing else. Explore plugins ### [Fine-grained governance](https://surrealdb.com/docs/learn/security) Least-privilege execution for multi-tenant clusters, with a permission expression per function. Explore security 01 |WASM SANDBOXING ## Isolated by design Each call creates a fresh WASM instance with its own memory. A module reaches SurrealDB only through explicit host functions, and data crosses the boundary by serialisation. SurrealDB Engine Query engine Parses and executes SurrealQL Transaction context Shared ACID boundary WASM Sandboxno filesystem · no direct DB · no raw network Module code User-defined Rust compiled to WASM Isolated memory Own store and instance per call 02 |BUILD PIPELINE ## How extensions work Write in Rust, compile to WebAssembly with the SurrealDB CLI, load into your instance, call from SurrealQL. Functions fn return_ten() -> i32 { 10 } fn is_positive(n: i32) -> bool { n >= 0 } Use #[surrealism] to expose functions: #[surrealism] fn return_ten() -> i32 { 10 } #[surrealism] fn is_positive(n: i32) -> bool { n >= 0 } surrealism.toml [package] organisation = "surrealdb" name = "demo" version = "1.0.0" Compile with SurrealDB CLI surreal module command Rust code ready to compile to WASM Compiled extension module SurrealDB instance Create file location with DEFINE BUCKET Access the compiled extension module with DEFINE MODULE Access functions inside SurrealDB CREATE person SET num = mod::test::return_ten(); SELECT id, mod::test::is_positive(num) AS is_positive FROM person; 03 |ZERO-DOWNTIME UPGRADES ## Hot-load, with the instance up Deploy, upgrade or roll back a module on a running instance. In-flight requests finish on the previous version while new requests load the update from storage. DEFINE MODULE OVERWRITE ml; Cache invalidation cache.remove(&lookup) - evicts the compiled Runtime In-flight requests Continue on Module v1 Arc stays valid New requests Cache miss → load from bucket Build new Runtime, cache it Complete normally Old runtime dropped when done Module v2 live Zero downtime transition 04 |TRANSACTION SAFETY ## Same transaction, same commit A module that calls back into SurrealQL runs in the transaction that invoked it, so its writes, the host callbacks and the original query commit or roll back as one. CREATE person SET score = mod::ml::predict(data); Single ACID transaction Query engine Parses SurrealQL, finds mod::call WASM module executes mod::ml::predict() runs in sandbox Host callback __sr_sql("SELECT * FROM training_data") Runs in same ctx and opt - same transaction Result returned Module returns prediction, query continues COMMIT Query + module writes + host callbacks - one atomic unit THE PLATFORM ## Everything an application and its agents know. Five surfaces, one engine. Database Document, graph, vector, time-series and relational in one engine. ![Five data models as dotted tiles: documents, graph, vector, time-series and relational](https://surrealdb.com/assets/static/platform-database.DUdumYDz.avif) Read more [Database](https://surrealdb.com/surrealdb) Agent Memory What an agent learns, with its source and its time, in the same engine. ![A timeline of remembered facts, each with its source](https://surrealdb.com/assets/static/platform-agent-memory.Cvv8D5Wl.avif) Read more [Agent Memory](https://surrealdb.com/agent-memory) Cloud Managed clusters in the regions you choose, scaled on demand. ![Clusters in three regions on a world map, each running or scaling](https://surrealdb.com/assets/static/platform-cloud.--QZnaVi.avif) Read more [Cloud](https://surrealdb.com/cloud) Studio Query, explore and design the schema from the browser. ![A SurrealQL query in Studio and the schema graph under it](https://surrealdb.com/assets/static/platform-studio.7ykBFNLq.avif) Read more [Studio](https://surrealdb.com/studio) MCP Every model that speaks MCP reaches the database and the memory directly. ![Three models connected through MCP to the database and Agent Memory](https://surrealdb.com/assets/static/platform-mcp.D_oH0_wm.avif) Read more [MCP](https://surrealdb.com/mcp) IN PRODUCTION ## Trusted at scale. Samsung, Nvidia, Verizon, Tencent, and Walmart run on SurrealDB. 14,000+ Developers building on SurrealDB Cloud 4M+ Developers building on SurrealDB worldwide FROM THE TEAMS > SurrealDB gives us a foundation where we can unify semantic search, knowledge graphs, and AI-driven decision making without stitching together multiple systems. Collapsing responsibility into SurrealDB has become our default engineering posture. *Justin Foley* VP of Engineering, Later GET STARTED ## Start building extensions. AI and application logic inside SurrealDB, as WebAssembly. [Read the docs](https://surrealdb.com/docs/learn/extensions) [Start free with SurrealDB](https://studio.surrealdb.com/current/instances/deploy) ```json {"@context":"https://schema.org","@type":"Organization","@id":"https://surrealdb.com/#organization","name":"SurrealDB","url":"https://surrealdb.com","logo":"https://surrealdb.com/assets/static/logo.BG7_TG2b.svg","description":"SurrealDB is the context and memory layer for AI agents. 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