Host Compatibility Profiler¶

The -profile mode connects once to a TN3270 host, probes its negotiated terminal model, protocol options, and discovered capabilities, and writes a CompatibilityProfile JSON document. The schema is shared byte-for-byte with 3270Web, so profiles produced by either tool can be compared side-by-side (for example, to spot divergence between an IBM z/OS image and a stripped-down Rocket Enterprise Server stand-in).

See Compatibility Profile Schema for the full field reference.

Quick start¶

3270Connect -profile -profileHost mvs01.example.com -profilePort 992 -profileTLS \
            -profileOut mvs01.profile.json

The probe connects, runs through s3270 Query requests against the host, captures the first screen's banner signature, records timing, and writes the JSON to -profileOut (or stdout when omitted). The process exits non-zero on failure so CI can fail fast.

Flags¶

Flag	Description
`-profile`	Enables one-shot profiler mode. Replaces the workflow runner for this invocation.
`-profileHost <host>`	Host to profile. If omitted, falls back to `Host` in the workflow config.
`-profilePort <port>`	Port to profile. If omitted, falls back to `Port` in the workflow config.
`-profileTLS`	Mark the profiled host as TLS-protected in the output (`host.tls: true`).
`-profileOut <path>`	Write the JSON to this path. When omitted, the document is emitted on stdout.
`-profileCollectRaw`	Include raw s3270 `Query` responses in the `raw` block of the JSON. Useful for debugging parser drift against new s3270 versions.

The probe uses a 30-second total timeout for capability discovery and the standard 5-second TCP dial timeout for the initial connection.

Reusing a workflow config¶

You can omit -profileHost/-profilePort and let the profiler pull them from -config:

3270Connect -profile -config workflow.json -profileOut current.profile.json

This makes it easy to drop -profile into an existing pipeline without duplicating connection metadata.

Example output¶

{
  "schema_version": "1.0.0",
  "run_id": "8f3b2c1a...",
  "timestamp": "2026-05-18T10:11:12Z",
  "profiler": { "tool": "3270Connect", "version": "1.8.6" },
  "host": {
    "host": "mvs01.example.com",
    "port": 992,
    "tls": true,
    "banner_signature": "9b6f...",
    "banner_preview": "WELCOME TO MVS01 ..."
  },
  "device": {
    "terminal_type": "IBM-3279-2-E",
    "rows": 24,
    "cols": 80,
    "color": true,
    "extended_attributes": true,
    "alt_screen": false
  },
  "protocol": { "tn3270e": true, "bind_image_present": true, "structured_fields": true },
  "capabilities": { "ind_file": "unknown", "query_reply_ids": ["..."], "unknown": [] },
  "timing": { "connect_ms": 142, "first_screen_ms": 38, "keyboard_unlock_ms": 38 }
}

Cross-environment comparison¶

Two profiles whose (device.terminal_type, host.banner_signature, protocol.tn3270e, protocol.structured_fields) tuples match are compatible at the wire level. Differences in capabilities.unknown highlight optional-feature gaps (e.g. IND$FILE on z/OS but not on a Rocket Enterprise Server image).

3270Web ships a complementary Chaos Mind-Map Compare endpoint that visualises these differences across hosts — feed both profiles to its POST /chaos/mindmap/compare to get a divergence report.

When to use which¶

3270Connect -profile — CI/CD or shell-friendly one-shot probe. No web UI needed; perfect for nightly fleet sweeps.
3270Web POST /profile — interactive use from the web UI or programmatic use from automation that already talks to 3270Web.

Both produce identical JSON; pick whichever fits the surrounding pipeline.