Module http_client

seq_runtime

Module http_client 

Source
Expand description

HTTP client operations for Seq

These functions are exported with C ABI for LLVM codegen to call.

§API

# GET request
"https://api.example.com/users" http.get
# Stack: ( Map ) where Map = { "status": 200, "body": "...", "ok": true }

# POST request
"https://api.example.com/users" "{\"name\":\"Alice\"}" "application/json" http.post
# Stack: ( Map ) where Map = { "status": 201, "body": "...", "ok": true }

# Check response
dup "ok" map.get if
  "body" map.get json.decode  # Process JSON body
else
  "error" map.get io.write-line  # Handle error
then

§Response Map

All HTTP operations return a Map with:

  • "status" (Int): HTTP status code (200, 404, 500, etc.) or 0 on connection error
  • "body" (String): Response body as text
  • "ok" (Bool): true if status is 2xx, false otherwise
  • "error" (String): Error message (only present on failure)

§Security: SSRF Protection

This HTTP client includes built-in protection against Server-Side Request Forgery (SSRF) attacks. The following are automatically blocked:

  • Localhost: localhost, *.localhost, 127.x.x.x
  • Private networks: 10.x.x.x, 172.16-31.x.x, 192.168.x.x
  • Link-local/Cloud metadata: 169.254.x.x (blocks AWS/GCP/Azure metadata endpoints)
  • IPv6 private: loopback (::1), link-local (fe80::/10), unique local (fc00::/7)
  • Non-HTTP schemes: file://, ftp://, gopher://, etc.

Blocked requests return an error response with ok=false and an explanatory message.

Additional recommendations for defense in depth:

  • Use domain allowlists for sensitive applications
  • Apply network-level egress filtering

§Resource Limits

  • Timeout: 30 seconds per request (prevents indefinite hangs)
  • Max body size: 10 MB (prevents memory exhaustion)
  • TLS: Enabled by default via rustls (no OpenSSL dependency)
  • Connection pooling: Enabled via shared agent instance

Functions§

patch_seq_http_delete⚠
Perform HTTP DELETE request
patch_seq_http_get⚠
Perform HTTP GET request
patch_seq_http_post⚠
Perform HTTP POST request
patch_seq_http_put⚠
Perform HTTP PUT request