base on A super fast Graph Database uses GraphBLAS under the hood for its sparse adjacency matrix graph representation. Our goal is to provide the best Knowledge Graph for LLM (GraphRAG). <div align="center"> <img width="100" height="100" alt="FalkorDB Logo Square B" src="https://github.com/user-attachments/assets/ec67e5e3-a060-405d-b229-1fe2badcf8ad" /> </div> <div align="center"> <h1>FalkorDB</h1> <h2>Ultra-fast, Multi-tenant Graph Database</h2> <h3>Powering Generative AI, Agent Memory, Cloud Security, and Fraud Detection</h3> </div> <div align="center"> <a href="https://app.falkordb.cloud/signup"> <img src="https://img.shields.io/badge/Try%20Free-FalkorDB%20Cloud-FF8101?labelColor=FDE900&style=for-the-badge" alt="Try Free" /> </a><br> <a href="https://discord.com/invite/TJ4SaPTptf" rel="nofollow"> <img src="https://img.shields.io/badge/Discord-%235865F2.svg?&logo=discord&logoColor=white" alt="Discord" /> </a> <a href="https://hub.docker.com/r/falkordb/falkordb/"> <img src="https://img.shields.io/docker/pulls/falkordb/falkordb?label=Docker" alt="Dockerhub" /> </a> <a href="https://discord.gg/6M4QwDXn2w"> <img src="https://img.shields.io/discord/1146782921294884966?style=flat-square" alt="Discord" /> </a> <a href="https://codecov.io/gh/falkordb/falkordb"> <img src="https://codecov.io/gh/falkordb/falkordb/graph/badge.svg?token=0G4HBEJMW0" alt="codecov" /> </a> <a href="https://github.com/FalkorDB/FalkorDB/actions/workflows/build.yml"> <img src="https://github.com/FalkorDB/FalkorDB/actions/workflows/build.yml/badge.svg?branch=master" alt="Workflow" /> </a> </div> --- ## UNIQUE FEATURES Our goal is to build a high-performance Knowledge Graph tailored for Large Language Models (LLMs), prioritizing exceptionally low latency to ensure fast and efficient information delivery through our Graph Database. 🆕 [FalkorDB](https://www.falkordb.com/) is the first **queryable [Property Graph](https://github.com/opencypher/openCypher/blob/master/docs/property-graph-model.adoc) database to leverage sparse matrices** for representing the [adjacency matrix](https://en.wikipedia.org/wiki/Adjacency_matrix) in graphs and [linear algebra](https://en.wikipedia.org/wiki/Adjacency_matrix) for querying. ### Key Features * **Sparse Matrix Representation**: Utilizes sparse matrices to represent adjacency matrices, optimizing storage and performance. * **Linear Algebra Querying**: Employs linear algebra for query execution, enhancing computational efficiency. * **Property Graph Model Compliance**: Supports nodes and relationships with attributes, adhering to the Property Graph Model. * **OpenCypher Support:** Compatible with [OpenCypher](ttps://github.com/opencypher/openCypher/blob/master/docs/property-graph-model.adoc) query language, including proprietary extensions for advanced querying capabilities. >Explore FalkorDB in action by visiting the [Demos](https://github.com/FalkorDB/FalkorDB/tree/master/demo). ## DOCUMENTATION [Official Docs](https://docs.falkordb.com/) | [Clients](https://docs.falkordb.com/clients.html) | [Commands](https://docs.falkordb.com/commands/) | 📊 [Latest Performance Benchmarks](https://benchmark.falkordb.com/) ### Community and Support * **Discussions**: Join our community discussions on [GitHub Discussions](https://github.com/FalkorDB/FalkorDB/discussions) to ask questions, share ideas, and connect with other users. * **Contributing**: We welcome contributions! Please see our [Contributing Guide](https://github.com/FalkorDB/FalkorDB/blob/master/CONTRIBUTING.md) for more details. * **License**: This project is licensed under the Server Side Public License v1 (SSPLv1). See the [LICENSE](https://github.com/FalkorDB/FalkorDB/blob/master/LICENSE.txt) file for details. ## GET STARTED ### Step 1 To quickly try out FalkorDB, launch an instance using docker: ``` docker run -p 6379:6379 -p 3000:3000 -it --rm -v ./data:/var/lib/falkordb/data falkordb/falkordb ``` ### Step 2 Then, open your browser and navigate to `http://localhost:3000`. You can also interact with FalkorDB using any of the supported [Client Libraries](https://docs.falkordb.com/clients.html) ### MotoGP League Example In this example, we'll use the [FalkorDB Python client](https://pypi.org/project/FalkorDB/) to create a small graph representing a subset of motorcycle riders and teams participating in the MotoGP league. After creating the graph, we'll query the data to explore its structure and relationships. ```python from falkordb import FalkorDB # Connect to FalkorDB db = FalkorDB(host='localhost', port=6379) # Create the 'MotoGP' graph g = db.select_graph('MotoGP') g.query("""CREATE (:Rider {name:'Valentino Rossi'})-[:rides]->(:Team {name:'Yamaha'}), (:Rider {name:'Dani Pedrosa'})-[:rides]->(:Team {name:'Honda'}), (:Rider {name:'Andrea Dovizioso'})-[:rides]->(:Team {name:'Ducati'})""") # Query which riders represents Yamaha? res = g.query("""MATCH (r:Rider)-[:rides]->(t:Team) WHERE t.name = 'Yamaha' RETURN r.name""") for row in res.result_set: print(row[0]) # Prints: "Valentino Rossi" # Query how many riders represent team Ducati ? res = g.query("""MATCH (r:Rider)-[:rides]->(t:Team {name:'Ducati'}) RETURN count(r)""") print(res.result_set[0][0]) # Prints: 1 ``` ## START BUILDING ### Compiling Make sure to complete these requirements: 1️⃣ The FalkorDB repository: `git clone --recurse-submodules -j8 https://github.com/FalkorDB/FalkorDB.git` >On Ubuntu Linux, run: `apt-get install build-essential cmake m4 automake peg libtool autoconf python3 python3-pip` >On OS X, verify that `homebrew` is installed and run: `brew install cmake m4 automake peg libtool autoconf`. >>The version of Clang that ships with the OS X toolchain does not support OpenMP, which is a requirement for FalkorDB. One way to resolve this is to run `brew install gcc g++` and follow the on-screen instructions to update the symbolic links. Note that this is a system-wide change - setting the environment variables for `CC` and `CXX` will work if that is not an option. 2️⃣ Build by running `make` in the project's directory. Congratulations! You can find the compiled binary at `bin/<arch>/src/falkordb.so`. ### Running tests Start by installing the required Python packages by running ```pip install -r requirements.txt``` from the ```tests``` directory. > Note: If you've got ```redis-server``` in PATH, just invoke ```make test```. Otherwise, invoke ```REDIS_SERVER=<redis-server-location> make test```. For a more verbose output, run ```make test V=1```. ### Building in a docker The FalkorDB build system runs within docker. For detailed instructions on building, please [see here](https://docs.falkordb.com/docker-examples/README.html). ## LOADING FALKORDB INTO REDIS FalkorDB is hosted by [Redis](https://redis.io), so you'll first have to load it as a Module to a Redis server. > Note: [Redis 7.4](https://redis.io/download) is required for the latest FalkorDB version. 💡 We recommend having Redis load FalkorDB during startup by adding the following to your redis.conf file: ``` loadmodule /path/to/module/src/falkordb.so ``` In the line above, replace `/path/to/module/src/falkordb.so` with the actual path to FalkorDB's library. If Redis is running as a service, you must ensure that the `redis` user (default) has the necessary file/folder permissions to access `falkordb.so`. Alternatively, you can have Redis load FalkorDB using the following command line argument syntax: ```sh ~/$ redis-server --loadmodule /path/to/module/src/falkordb.so ``` Lastly, you can also use the [`MODULE LOAD`](http://redis.io/commands/module-load) command. Note, however, that `MODULE LOAD` is a dangerous command and may be blocked/deprecated in the future due to security considerations. Once you've successfully loaded FalkorDB your Redis log should see lines similar to: ``` ... 30707:M 20 Jun 02:08:12.314 * Module 'graph' loaded from <redacted>/src/falkordb.so ... ``` If the server fails to launch with output similar to: ``` # Module /usr/lib/redis/modules/falkordb.so failed to load: libgomp.so.1: cannot open shared object file: No such file or directory # Can't load module from /usr/lib/redis/modules/falkordb.so: server aborting ``` The system is missing the run-time dependency OpenMP. This can be installed on Ubuntu with `apt-get install libgomp1`, on RHEL/CentOS with `yum install libgomp`, and on OSX with `brew install libomp`. ## USING FALKORDB You can call FalkorDB's commands from any Redis client. Here are several methods: ### With `redis-cli` ```sh $ redis-cli 127.0.0.1:6379> GRAPH.QUERY social "CREATE (:person {name: 'roi', age: 33, gender: 'male', status: 'married'})" ``` ### With any other client You can interact with FalkorDB using your client's ability to send raw Redis commands. >Note: Depending on your client of choice, the exact method for doing that may vary. #### Example: Using FalkorDB with a Python client This code snippet shows how to use FalkorDB with from Python using [falkordb-py](https://github.com/FalkorDB/falkordb-py): ```Python from falkordb import FalkorDB # Connect to FalkorDB db = FalkorDB(host='localhost', port=6379) # Select the social graph g = db.select_graph('social') reply = g.query("CREATE (:person {name:'roi', age:33, gender:'male', status:'married'})") ``` ## CLIENT LIBRARIES >Note: Some languages have client libraries that provide support for FalkorDB's commands: ### Official Clients | Project | Language | License | Author | Stars | Package | Comment | | --------------------------------------------------------- | ---------- | ------- | ------------------------------------------- | ----------------------------------------------------------------- | ------- | ---------- | | [jfalkordb][jfalkordb-url] | Java | BSD | [FalkorDB][falkordb-url] | [![jfalkordb-stars]][jfalkordb-url] | [Maven][jfalkordb-package]|| | [falkordb-py][falkordb-py-url] | Python | MIT | [FalkorDB][falkordb-url] | [![falkordb-py-stars]][falkordb-py-url] | [pypi][falkordb-py-package]|| | [falkordb-ts][falkordb-ts-url] | Node.JS | MIT | [FalkorDB][falkordb-url] | [![falkordb-ts-stars]][falkordb-ts-url] | [npm][falkordb-ts-package]|| | [falkordb-rs][falkordb-rs-url] | Rust | MIT | [FalkorDB][falkordb-url] | [![falkordb-rs-stars]][falkordb-rs-url] | [Crate][falkordb-rs-package]|| | [falkordb-go][falkordb-go-url] | Go | BSD | [FalkorDB][falkordb-url] | [![falkordb-go-stars]][falkordb-go-url] | [GitHub][falkordb-go-url]|| | [NFalkorDB][nfalkordb-url] | C# | Apache-2.0 | [FalkorDB][falkordb-url] | [![nfalkordb-stars]][nfalkordb-url] | [nuget][nfalkordb-package] | | ### Additional Clients | Project | Language | License | Author | Stars | Package | Comment | | --------------------------------------------------------- | ---------- | ------- | ------------------------------------------- | ----------------------------------------------------------------- | ------- | ---------- | | [nredisstack][nredisstack-url] | .NET | MIT | [Redis][redis-url] | [![nredisstack-stars]][nredisstack-url] | [nuget][nredisstack-package]|| | [redisgraph-rb][redisgraph-rb-url] | Ruby | BSD | [Redis][redisgraph-rb-author] | [![redisgraph-rb-stars]][redisgraph-rb-url] | [GitHub][redisgraph-rb-url] || | [redgraph][redgraph-url] | Ruby | MIT | [pzac][redgraph-author] | [![redgraph-stars]][redgraph-url] | [GitHub][redgraph-url] || | [redisgraph-go][redisgraph-go-url] | Go | BSD | [Redis][redisgraph-go-author] | [![redisgraph-go-stars]][redisgraph-go-url] | [GitHub][redisgraph-go-url]|| | [rueidis][rueidis-url] | Go | Apache 2.0 | [Rueian][rueidis-author] | [![rueidis-stars]][rueidis-url] | [GitHub][rueidis-url] || | [ioredisgraph][ioredisgraph-url] | JavaScript | ISC | [Jonah][ioredisgraph-author] | [![ioredisgraph-stars]][ioredisgraph-url] | [GitHub][ioredisgraph-url] || | [@hydre/rgraph][rgraph-url] | JavaScript | MIT | [Sceat][rgraph-author] | [![rgraph-stars]][rgraph-url] | [GitHub][rgraph-url] || | [php-redis-graph][php-redis-graph-url] | PHP | MIT | [KJDev][php-redis-graph-author] | [![php-redis-graph-stars]][php-redis-graph-url] | [GitHub][php-redis-graph-url] || | [redisgraph_php][redisgraph_php-url] | PHP | MIT | [jpbourbon][redisgraph_php-author] | [![redisgraph_php-stars]][redisgraph_php-url] | [GitHub][redisgraph_php-url] || | [redisgraph-ex][redisgraph-ex-url] | Elixir | MIT | [crflynn][redisgraph-ex-author] | [![redisgraph-ex-stars]][redisgraph-ex-url] | [GitHub][redisgraph-ex-url] || | [redisgraph-rs][redisgraph-rs-url] | Rust | MIT | [malte-v][redisgraph-rs-author] | [![redisgraph-rs-stars]][redisgraph-rs-url] | [GitHub][redisgraph-rs-url] || | [redis_graph][redis_graph-url] | Rust | BSD | [tompro][redis_graph-author] | [![redis_graph-stars]][redis_graph-url] | [GitHub][redis_graph-url] || | [rustis][rustis-url] | Rust | MIT | [Dahomey Technologies][rustis-author] | [![rustis-stars]][rustis-url] | [Crate](https://crates.io/crates/rustis) | [Documentation](https://docs.rs/rustis/latest/rustis/commands/trait.GraphCommands.html) | | [NRedisGraph][NRedisGraph-url] | C# | BSD | [tombatron][NRedisGraph-author] | [![NRedisGraph-stars]][NRedisGraph-url] | [GitHub][NRedisGraph-url] || | [RedisGraph.jl][RedisGraph.jl-url] | Julia | MIT | [xyxel][RedisGraph.jl-author] | [![RedisGraph.jl-stars]][RedisGraph.jl-url] | [GitHub][RedisGraph.jl-url] || [redis-url]: https://redis.com [falkordb-url]: https://www.falkordb.com [falkordb-py-url]: http://github.com/falkorDB/falkordb-py [falkordb-py-stars]: https://img.shields.io/github/stars/falkorDB/falkordb-py.svg?style=social&amp;label=Star&amp;maxAge=2592000 [falkordb-py-package]: https://pypi.org/project/FalkorDB [jfalkordb-url]: https://github.com/falkordb/jfalkordb [jfalkordb-stars]: https://img.shields.io/github/stars/falkordb/jfalkordb.svg?style=social&amp;label=Star&amp;maxAge=2592000 [jfalkordb-package]: https://search.maven.org/artifact/com.falkordb/jfalkordb [nfalkordb-url]: https://github.com/falkordb/NFalkorDB [nfalkordb-stars]: https://img.shields.io/github/stars/falkordb/nfalkordb.svg?style=social&label=Star&maxAge=2592000 [nfalkordb-package]: https://www.nuget.org/packages/NFalkorDB [nredisstack-url]: https://github.com/redis/nredisstack [nredisstack-stars]: https://img.shields.io/github/stars/redis/nredisstack.svg?style=social&amp;label=Star&amp;maxAge=2592000 [nredisstack-package]: https://www.nuget.org/packages/nredisstack/ [falkordb-ts-url]: https://github.com/falkordb/falkordb-ts [falkordb-ts-stars]: https://img.shields.io/github/stars/falkordb/falkordb-ts.svg?style=social&amp;label=Star&amp;maxAge=2592000 [falkordb-ts-package]: https://www.npmjs.com/package/falkordb [falkordb-rs-url]: https://github.com/falkordb/falkordb-rs [falkordb-rs-stars]: https://img.shields.io/github/stars/falkordb/falkordb-rs.svg?style=social&amp;label=Star&amp;maxAge=2592000 [falkordb-rs-package]: https://crates.io/crates/falkordb [falkordb-go-url]: https://github.com/falkordb/falkordb-go [falkordb-go-stars]: https://img.shields.io/github/stars/falkordb/falkordb-go.svg?style=social&amp;label=Star&amp;maxAge=2592000 [falkordb-go-package]: https://github.com/falkordb/falkordb-go [redisgraph-rb-author]: https://redislabs.com [redisgraph-rb-url]: https://github.com/RedisGraph/redisgraph-rb [redisgraph-rb-stars]: https://img.shields.io/github/stars/RedisGraph/redisgraph-rb.svg?style=social&amp;label=Star&amp;maxAge=2592000 [redgraph-author]: https://github.com/pzac [redgraph-url]: https://github.com/pzac/redgraph [redgraph-stars]: https://img.shields.io/github/stars/pzac/redgraph.svg?style=social&amp;label=Star&amp;maxAge=2592000 [redisgraph-go-author]: https://redislabs.com [redisgraph-go-url]: https://github.com/RedisGraph/redisgraph-go [redisgraph-go-stars]: https://img.shields.io/github/stars/RedisGraph/redisgraph-go.svg?style=social&amp;label=Star&amp;maxAge=2592000 [rueidis-url]: https://github.com/rueian/rueidis [rueidis-author]: https://github.com/rueian [rueidis-stars]: https://img.shields.io/github/stars/rueian/rueidis.svg?style=social&amp;label=Star&amp;maxAge=2592000 [rgraph-author]: https://github.com/Sceat [rgraph-url]: https://github.com/HydreIO/rgraph [rgraph-stars]: https://img.shields.io/github/stars/HydreIO/rgraph.svg?style=social&amp;label=Star&amp;maxAge=2592000 [ioredisgraph-author]: https://github.com/Jonahss [ioredisgraph-url]: https://github.com/Jonahss/ioredisgraph [ioredisgraph-stars]: https://img.shields.io/github/stars/Jonahss/ioredisgraph.svg?style=social&amp;label=Star&amp;maxAge=2592000 [php-redis-graph-author]: https://github.com/kjdev [php-redis-graph-url]: https://github.com/kjdev/php-redis-graph [php-redis-graph-stars]: https://img.shields.io/github/stars/kjdev/php-redis-graph.svg?style=social&amp;label=Star&amp;maxAge=2592000 [redisgraph_php-author]: https://github.com/jpbourbon [redisgraph_php-url]: https://github.com/jpbourbon/redisgraph_php [redisgraph_php-stars]: https://img.shields.io/github/stars/jpbourbon/redisgraph_php.svg?style=social&amp;label=Star&amp;maxAge=2592000 [redislabs-redisgraph-php-author]: https://github.com/mkorkmaz [redislabs-redisgraph-php-url]: https://github.com/mkorkmaz/redislabs-redisgraph-php [redislabs-redisgraph-php-stars]: https://img.shields.io/github/stars/mkorkmaz/redislabs-redisgraph-php.svg?style=social&amp;label=Star&amp;maxAge=2592000 [redisgraph-ex-author]: https://github.com/crflynn [redisgraph-ex-url]: https://github.com/crflynn/redisgraph-ex [redisgraph-ex-stars]: https://img.shields.io/github/stars/crflynn/redisgraph-ex.svg?style=social&amp;label=Star&amp;maxAge=2592000 [redisgraph-rs-author]: https://github.com/malte-v [redisgraph-rs-url]: https://github.com/malte-v/redisgraph-rs [redisgraph-rs-stars]: https://img.shields.io/github/stars/malte-v/redisgraph-rs.svg?style=social&amp;label=Star&amp;maxAge=2592000 [redis_graph-author]: https://github.com/tompro [redis_graph-url]: https://github.com/tompro/redis_graph [redis_graph-stars]: https://img.shields.io/github/stars/tompro/redis_graph.svg?style=social&amp;label=Star&amp;maxAge=2592000 [NRedisGraph-author]: https://github.com/tombatron [NRedisGraph-url]: https://github.com/tombatron/NRedisGraph [NRedisGraph-stars]: https://img.shields.io/github/stars/tombatron/NRedisGraph.svg?style=social&amp;label=Star&amp;maxAge=2592000 [RedisGraphDotNet.Client-author]: https://github.com/Sgawrys [RedisGraphDotNet.Client-url]: https://github.com/Sgawrys/RedisGraphDotNet.Client [RedisGraphDotNet.Client-stars]: https://img.shields.io/github/stars/Sgawrys/RedisGraphDotNet.Client.svg?style=social&amp;label=Star&amp;maxAge=2592000 [RedisGraph.jl-author]: https://github.com/xyxel [RedisGraph.jl-url]: https://github.com/xyxel/RedisGraph.jl [RedisGraph.jl-stars]: https://img.shields.io/github/stars/xyxel/RedisGraph.jl.svg?style=social&amp;label=Star&amp;maxAge=2592000 [rustis-url]: https://github.com/dahomey-technologies/rustis [rustis-author]: https://github.com/dahomey-technologies [rustis-stars]: https://img.shields.io/github/stars/dahomey-technologies/rustis.svg?style=social&amp;label=Star&amp;maxAge=2592000 ## LICENSE Licensed under the Server Side Public License v1 (SSPLv1). See [LICENSE](LICENSE.txt). ### Support our work ⭐️ If you find this repository helpful, please consider giving it a star! ↗️ Graph, graph database, RAG, graphrag, Retrieval-Augmented Generation,Information Retrieval, Natural Language Processing, LLM, Embeddings, Semantic Search ", Assign "at most 3 tags" to the expected json: {"id":"14787","tags":[]} "only from the tags list I provide: [{"id":77,"name":"3d"},{"id":89,"name":"agent"},{"id":17,"name":"ai"},{"id":54,"name":"algorithm"},{"id":24,"name":"api"},{"id":44,"name":"authentication"},{"id":3,"name":"aws"},{"id":27,"name":"backend"},{"id":60,"name":"benchmark"},{"id":72,"name":"best-practices"},{"id":39,"name":"bitcoin"},{"id":37,"name":"blockchain"},{"id":1,"name":"blog"},{"id":45,"name":"bundler"},{"id":58,"name":"cache"},{"id":21,"name":"chat"},{"id":49,"name":"cicd"},{"id":4,"name":"cli"},{"id":64,"name":"cloud-native"},{"id":48,"name":"cms"},{"id":61,"name":"compiler"},{"id":68,"name":"containerization"},{"id":92,"name":"crm"},{"id":34,"name":"data"},{"id":47,"name":"database"},{"id":8,"name":"declarative-gui "},{"id":9,"name":"deploy-tool"},{"id":53,"name":"desktop-app"},{"id":6,"name":"dev-exp-lib"},{"id":59,"name":"dev-tool"},{"id":13,"name":"ecommerce"},{"id":26,"name":"editor"},{"id":66,"name":"emulator"},{"id":62,"name":"filesystem"},{"id":80,"name":"finance"},{"id":15,"name":"firmware"},{"id":73,"name":"for-fun"},{"id":2,"name":"framework"},{"id":11,"name":"frontend"},{"id":22,"name":"game"},{"id":81,"name":"game-engine "},{"id":23,"name":"graphql"},{"id":84,"name":"gui"},{"id":91,"name":"http"},{"id":5,"name":"http-client"},{"id":51,"name":"iac"},{"id":30,"name":"ide"},{"id":78,"name":"iot"},{"id":40,"name":"json"},{"id":83,"name":"julian"},{"id":38,"name":"k8s"},{"id":31,"name":"language"},{"id":10,"name":"learning-resource"},{"id":33,"name":"lib"},{"id":41,"name":"linter"},{"id":28,"name":"lms"},{"id":16,"name":"logging"},{"id":76,"name":"low-code"},{"id":90,"name":"message-queue"},{"id":42,"name":"mobile-app"},{"id":18,"name":"monitoring"},{"id":36,"name":"networking"},{"id":7,"name":"node-version"},{"id":55,"name":"nosql"},{"id":57,"name":"observability"},{"id":46,"name":"orm"},{"id":52,"name":"os"},{"id":14,"name":"parser"},{"id":74,"name":"react"},{"id":82,"name":"real-time"},{"id":56,"name":"robot"},{"id":65,"name":"runtime"},{"id":32,"name":"sdk"},{"id":71,"name":"search"},{"id":63,"name":"secrets"},{"id":25,"name":"security"},{"id":85,"name":"server"},{"id":86,"name":"serverless"},{"id":70,"name":"storage"},{"id":75,"name":"system-design"},{"id":79,"name":"terminal"},{"id":29,"name":"testing"},{"id":12,"name":"ui"},{"id":50,"name":"ux"},{"id":88,"name":"video"},{"id":20,"name":"web-app"},{"id":35,"name":"web-server"},{"id":43,"name":"webassembly"},{"id":69,"name":"workflow"},{"id":87,"name":"yaml"}]" returns me the "expected json"