An ATProto Lexicon validator for Gleam.
chadtmiller.com
1# Jetstream Validation Example
2
3This example demonstrates using **honk** to validate AT Protocol records from Bluesky's Jetstream firehose in real-time.
4
5## What it does
6
71. Connects to Jetstream using **goose** (WebSocket consumer)
82. Filters for `xyz.statusphere.status` records
93. Validates each record using **honk**
104. Displays validation results with emoji status
11
12## Running the example
13
14```sh
15cd example
16gleam run
17```
18
19The example will connect to the live Jetstream firehose and display validation results as records are created:
20
21```
22🦢 Honk + Goose: Jetstream Validation Example
23━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
24
25Connecting to Jetstream...
26Filtering for: xyz.statusphere.status
27Validating records with honk...
28
29✓ VALID | q6gjnaw2blty... | 👍 | 3l4abc123
30✓ VALID | wa7b35aakoll... | 🎉 | 3l4def456
31✗ INVALID | rfov6bpyztcn... | Data: status exceeds maxGraphemes | 3l4ghi789
32✓ UPDATED | eygmaihciaxp... | 😀 | 3l4jkl012
33🗑️ DELETED | ufbl4k27gp6k... | 3l4mno345
34```
35
36## How it works
37
38### Lexicon Definition
39
40The example defines the `xyz.statusphere.status` lexicon:
41
42```json
43{
44 "lexicon": 1,
45 "id": "xyz.statusphere.status",
46 "defs": {
47 "main": {
48 "type": "record",
49 "record": {
50 "type": "object",
51 "required": ["status", "createdAt"],
52 "properties": {
53 "status": {
54 "type": "string",
55 "minLength": 1,
56 "maxGraphemes": 1,
57 "maxLength": 32
58 },
59 "createdAt": {
60 "type": "string",
61 "format": "datetime"
62 }
63 }
64 }
65 }
66 }
67}
68```
69
70### Validation Flow
71
721. **goose** receives Jetstream events via WebSocket
732. Events are parsed into typed Gleam structures
743. For `create` and `update` operations:
75 - Extract the `record` field (contains the status data)
76 - Pass to `honk.validate_record()` with the lexicon
77 - Display ✓ for valid or ✗ for invalid records
784. For `delete` operations:
79 - Just log the deletion (no record to validate)
80
81### Dependencies
82
83- **honk**: AT Protocol lexicon validator (local path)
84- **goose**: Jetstream WebSocket consumer library
85- **gleam_json**: JSON encoding/decoding
86- **gleam_stdlib**: Standard library
87
88## Code Structure
89
90```
91example/
92├── gleam.toml # Dependencies configuration
93├── README.md # This file
94└── src/
95 └── example.gleam # Main application
96 ├── main() # Entry point
97 ├── handle_event() # Process Jetstream events
98 ├── handle_create/update() # Validate records
99 ├── create_statusphere_lexicon()# Define lexicon
100 └── format_error/extract_status # Display helpers
101```
102
103## Learn More
104
105- **honk**: https://hexdocs.pm/honk
106- **goose**: https://hexdocs.pm/goose
107- **Jetstream**: https://docs.bsky.app/docs/advanced-guides/jetstream
108- **AT Protocol**: https://atproto.com/