JSON Repair Go

Repair invalid JSON strings in Go. Especially handy for cleaning up JSON coming from Large Language Models (LLMs) or hand-written configs.

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Features

• Fix missing/wrong quotes on keys and strings
• Convert single quotes to double quotes
• Add missing commas, closing braces/brackets
• Remove trailing commas
• Normalize booleans (True/False ➜ true/false) and nulls (None ➜ null)
• Strip comments (//, /* */, #)
• Light escaping and number parsing fixes
• Zero external deps (stdlib only)

Install

go get github.com/lxw665/json_repair_go

Note: make sure your import path matches the repository path you publish under. If you fork, replace lxw665 with your GitHub username.

Quick start

package main

import (
    "fmt"
    "log"
    jsonrepair "github.com/lxw665/json_repair_go"
)

func main() {
    broken := `{name: 'John', age: 30, active: True`

    // 1) Repair to JSON string
    fixed, err := jsonrepair.RepairJSON(broken)
    if err != nil { log.Fatal(err) }
    fmt.Println(fixed) // {"name":"John","age":30,"active":true}

    // 2) Parse directly to Go value
    v, err := jsonrepair.Loads(broken)
    if err != nil { log.Fatal(err) }
    fmt.Printf("%+v\n", v)
}

API

• RepairJSON(jsonStr string) (string, error) — Repair and return a JSON string
• RepairJSONWithOptions(jsonStr string, options RepairOptions) (string, error)
• Loads(jsonStr string) (interface{}, error) — Repair and parse to Go values
• Unmarshal(data []byte, v any) error — Drop-in for json.Unmarshal with repair
• Load(r io.Reader, v any) error

Options:

type RepairOptions struct {
    SkipValidation bool // Skip initial json.Unmarshal check
    ReturnObjects  bool // Return parsed objects instead of JSON string
    Logging        bool // Enable repair logs
    StreamStable   bool // Keep repair stable for streaming use-cases
    EnsureASCII    bool // Escape non-ASCII
}

Examples

Input ➜ Output

• {name: 'John', age: 30 ➜ {"name":"John","age":30}
• {'key': 'value',} ➜ {"key":"value"}
• [1, 2, 3, ➜ [1,2,3]
• {"active": True} ➜ {"active":true}
• {"value": None} ➜ {"value":null}
• {a: 1, b: 2 ➜ {"a":1,"b":2}

More runnable examples in demo/:

cd demo
go run .

Testing

go test -v
go test -bench=.
go test -cover

Related work

• Python: https://github.com/mangiucugna/json_repair
• TypeScript: https://github.com/josdejong/jsonrepair
• Rust: https://github.com/oramasearch/llm_json
• Ruby: https://github.com/sashazykov/json-repair-rb

Contributing

PRs and issues are welcome.

1. Fork ➜ 2) create branch ➜ 3) commit ➜ 4) push ➜ 5) open PR

License

MIT. See LICENSE.

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If this project helps you, please give it a ⭐️!