snago — HTTP request capture & replay tool

Capture, inspect, and replay any HTTP request. Point any traffic at snago — webhooks, API calls, form submissions, health checks — and it saves every request to disk. Replay them later against any target with headers, body, and query strings fully preserved.

Single binary, zero runtime dependencies.

Use cases

• API development — Capture requests from any client, inspect what was actually sent, and replay to reproduce issues or test changes.
• Webhook debugging — Point GitHub/Stripe/Slack webhooks at snago, inspect payloads, and replay them while iterating on your handler.
• Request archiving — Persist incoming traffic for later analysis without modifying your application.
• Integration testing — Record real requests from third-party services and replay them against your local environment.

Install

go install github.com/nikooo777/snago@latest

Or build from source:

git clone https://github.com/nikooo777/snago.git
cd snago
make build

Quick start

# 1. Start capturing
snago serve

# 2. Send any request (from another terminal)
curl -X POST -H "Content-Type: application/json" \
  -d '{"action":"test"}' http://localhost:7624/any/path

# 3. Inspect the captured request
snago inspect captures/<file>.gob

# 4. Replay it to your real server
snago replay --target http://localhost:9090 captures/<file>.gob

Commands

snago serve

Start an HTTP server that captures every incoming request to a .gob file. All requests receive a 200 OK response with body ok — it acts as a universal sink.

snago serve [--addr :7624] [--dir ./captures] [--verbose] [--no-body]

Flag	Default	Description
--addr	:7624	Listen address
--dir	./captures	Output directory for captured .gob files
--verbose	false	Print full request details (headers + body) for each capture
--no-body	false	Hide request body from verbose output

Example output:

$ snago serve
INFO snago listening addr=:7624 dir=./captures
POST /api/orders 5 headers 66b → 1771366415797329694_38aab851.gob
GET /health 2 headers 0b → 1771366415801479108_bd746ac6.gob

The server shuts down gracefully on Ctrl+C. If running behind a reverse proxy, it reads X-Forwarded-Proto to detect the original scheme (http/https).

snago inspect

Pretty-print a captured request — method, URL, timestamp, headers, and body. Binary bodies are shown as [binary data, N bytes] instead of raw bytes.

snago inspect [--save-body [file]] [--no-body] <file.gob>

Flag	Default	Description
--save-body	(off)	Save request body to a file. Omit filename for auto-detection (MIME-based extension)
--no-body	false	Hide request body from output

$ snago inspect captures/1771366415797329694_38aab851.gob
POST https://example.com/api/orders
Captured: 2026-02-17 23:15:56

Content-Type: application/json
Authorization: Bearer tok_xxx

{"item":"widget","qty":3}

Extract the body with automatic filename and extension detection:

# Auto-detect: generates 1771366415797329694_38aab851_body.json
snago inspect --save-body captures/1771366415797329694_38aab851.gob

# Explicit path
snago inspect --save-body=payload.json captures/1771366415797329694_38aab851.gob

snago replay

Re-send a captured request. By default, replays to the original host. Use --target to redirect it.

snago replay [--target URL] [--verbose] <file.gob>

Flag	Default	Description
--target	(original host)	Override destination URL (scheme://host)
--verbose	false	Print full response details (headers + body)

# Replay to original destination
snago replay captures/1771366415797329694_38aab851.gob

# Replay to a different host (path and query string are preserved)
snago replay --target http://localhost:9090 captures/1771366415797329694_38aab851.gob

Hop-by-hop headers (Connection, Transfer-Encoding, Content-Length) are automatically stripped before sending.

snago version

snago version
# or
snago --version

Environment variables

All flags can be set via environment variables (flags take precedence when both are set):

Variable	Flag equivalent	Default
SNAGO_SERVE_ADDR	--addr	:7624
SNAGO_SERVE_DIR	--dir	./captures
SNAGO_SERVE_VERBOSE	--verbose	false
SNAGO_REPLAY_TARGET	--target	(empty)
SNAGO_REPLAY_VERBOSE	--verbose	false

License

MIT