recon-tool 2.6.9

Public-metadata domain intelligence CLI and MCP server using DNS, certificate transparency, and unauthenticated identity discovery.

recon

Passive domain intelligence from public sources. recon reads public DNS, certificate transparency, and unauthenticated Microsoft and Google identity discovery endpoints to compose typed observations around a domain's public technology and identity namespace. A domain is the query coordinate, not proof of one organization, owner, account, or deployed product.

It uses no credentials, no API keys, no paid feeds, and no active scanning. It ships as a local Python package with a CLI, versioned JSON output, and a stdio MCP server. It is not a hosted service, scheduler, vulnerability scanner, company research tool, or firmographic database.

Defensive use only. Use recon for legitimate posture review, IT architecture review, vendor diligence, and defensive hardening. See docs/legal.md for the intended-use policy.

Quick Start

Install with uv or pipx:

uv tool install recon-tool
# or
pipx install recon-tool

Python 3.11 through 3.14 is supported. The latest Python 3.14 patch is recommended for new installations and development; older supported versions retain the same product behavior and output contracts. Current measurements and version-specific decisions are in docs/performance.md.

Optional helpers at scripts/install.ps1 and scripts/install.sh use an existing uv or pipx installation. Download a release-tag source archive, review the local helper, and then run it. Each helper installs the exact version represented by that tag, preserves a sole existing uv or pipx owner, and refuses ambiguous or unmanaged installations. Review the helper from a newer tag before using it to update. Do not pipe mutable branch content directly into a shell.

For a provenance-first path that verifies the exact GitHub and PyPI artifacts, their signed evidence, and their byte parity before optional installation, use the cross-platform consumer verification recipe. The release workflow in this source revision signs the completed SBOM with the distributions and validates any existing release's exact identity and expected-only inventory before replacing assets during recovery. The published v2.6.3 bundle predates the SBOM subject expansion; the quick path binds that single historical exception to its exact commit and still validates the SBOM.

Open a new terminal and run an offline verification of the installed command:

recon --version

Optionally test online connectivity to recon's public data sources:

recon doctor

The default diagnostic uses synthetic requests to Microsoft identity endpoints, DNS for example.com, and crt.sh. It does not query a user-supplied target. The --fix, --mcp, and --client modes are local-only.

Before the first lookup, note that recon makes DNS queries which recursive and authoritative DNS infrastructure may observe. Its only default request to a target-owned HTTP endpoint is the standards-defined MTA-STS policy fetch at https://mta-sts.<domain>/.well-known/mta-sts.txt. Google CSE and BIMI direct probes run only when --direct-probes is explicitly enabled.

Run the first lookup:

recon example.com

If a lookup times out or every online source fails, run recon doctor to check source connectivity, then retry the lookup.

Example output shape:

Synthetic Example Namespace
example.com

Provider     Microsoft 365 (MX delivery path) + Proofpoint gateway (MX delivery path)
Tenant       a1b2c3d4-e5f6-7890-abcd-ef1234567890
Auth         Federated
Confidence   High (4 sources)

Services
  Email       Microsoft 365, Proofpoint, DMARC, DKIM, SPF strict
  Identity    Okta, Entra ID
  Cloud       Cloudflare, AWS Route 53

Insights
  Federated identity observed; identity-vendor indicators: Okta
  Email security: observed controls: DMARC reject, DKIM, SPF strict, BIMI
  MX gateway observed: Proofpoint

Examples use IETF reserved namespaces. Tenant IDs, services, and domains in this rendered example are fabricated. No real organization is depicted as the evaluated target.

For detailed install, update, uninstall, and first-run workflows, read docs/getting-started.md.

What recon Is Good For

Need	Use recon for	Use something else when
Fast external stack context	Passive DNS, identity-endpoint, CT, SaaS, and posture indicators	You need authenticated tenant inventory or asset-management truth
Defensive review or vendor diligence	Hedged observations and evidence traces you can verify	You need vulnerability scanning, exploit checks, or host-level facts
Automation-friendly output	Stable JSON, batch mode, delta mode, and local MCP tools	You need dashboards, scheduling, or report generation built in

recon reports observations, not verdicts. A missing DMARC record is a missing record. A Microsoft 365 tenant indicator is an observed indicator. The operator decides what those facts mean in context.

Common Commands

recon example.com                              # default panel
recon https://www.example.com/path             # normalize URL to apex
recon mail.example.com                         # reduce sub-host to apex
recon mail.example.com --exact                 # keep that literal host
recon example.com --explain                    # retained evidence and explanation
recon example.com --full                       # expanded evidence, domains, posture
recon example.com --plain                      # linear text for screen readers and grep
recon example.com --json                       # structured lookup record
recon batch domains.txt --json                 # batch JSON array
recon batch domains.txt --ndjson               # one record per line
recon batch domains.txt --summary              # aggregate-only cohort summary
recon delta example.com                        # diff against cached snapshot
recon cache show                               # bounded payload-free cache overview
recon cache show --all                         # inspect every completed JSON cache file
recon cache show mail.example.com --exact      # inspect literal-host result and CT cache metadata
recon cache clear mail.example.com --exact     # clear literal-host CT and result cache keys
recon mcp install --client=cursor              # wire MCP into a client
recon doctor --mcp                             # static MCP registry check
recon mcp doctor                               # live MCP tools/resources check
recon doctor --client=cursor                   # verify the client config

The default cache overview enumerates filenames but opens at most the lexicographically first 100 result files and 100 CT files. It reports exact file and uninspected counts; --all opts into complete JSON payload inspection. Cache-writer-shaped interrupted-write artifacts are counted without reading their payload, make the overview exit 4, and are removed by the confirmed recon cache clear --all workflow.

These list, search, and show catalog commands are local and make no network requests:

recon fingerprints list                       # summarize public-record matchers
recon fingerprints search email               # preview matching fingerprint slugs
recon fingerprints show <slug>                 # show every record and rule for one slug
recon signals list                             # list derived reportable observations
recon signals search email                     # search signal definitions
recon signals show "<signal name>"             # inspect one signal definition

A fingerprint slug is a named public-record indicator. One slug can intentionally have multiple catalog records, and show preserves every record, detection, relationship hint, tier, and verification date. A signal is a derived, reportable observation definition built from candidate fingerprint slugs and metadata conditions. Human fingerprint search previews at most ten unique slugs; --json returns every matching catalog record. Category filters use the same word-prefix or phrase rule in the CLI and MCP server. Human catalog detail output strips terminal controls from locally extended text and visibly marks values truncated after 1,024 characters.

At terminal widths below 70 columns, command help automatically switches to a complete linear layout so long option names and command summaries remain visible without source markup. The no-argument welcome also switches to vertical command descriptions whenever an aligned row would not fit, including at ordinary widths. --plain is the linear view for a standard single-domain lookup; batch, delta, chain, compare, exposure, and gaps reports keep their mode-specific formats.

Built-in posture profiles: fintech, healthcare, saas-b2b, high-value-target, public-sector, and higher-ed. Custom profiles live in ~/.recon/profiles/*.yaml.

Generated command and flag reference: docs/cli-surface.md.

How recon Works

recon reads:

• DNS records: MX, TXT, SPF, DMARC, DKIM, BIMI, CNAME, NS, SRV, and CAA.
• Certificate transparency: SAN names, issuers, issuance timing, and bounded related-domain hints.
• Identity discovery: unauthenticated Microsoft and Google endpoints.

Default collection includes bounded DNS queries through the configured recursive resolver, so authoritative DNS infrastructure may observe resulting resolver traffic. The only default target-owned HTTP or application request is the standards-based MTA-STS policy fetch at mta-sts.<domain>. Google CSE and BIMI VMC direct probes are opt-in behind --direct-probes.

The engine then maps observables to fingerprint slugs, derived signals, typed topology, provenance paths, per-slug evidence strength, and model-relative Bayesian diagnostics. Sparse public evidence stays sparse: the result lowers confidence or remains unresolved instead of inventing a clean answer. A source failure remains unavailable rather than becoming a negative observation. The Bayesian uncertainty band is evidence-responsive, not a demonstrated credible or confidence interval.

The reviewed built-in fingerprint source remains split YAML. Release wheels load one deterministic generated JSON catalog, while custom and session-scoped fingerprints still pass through the runtime validator. This keeps contributor review readable and removes repeated YAML parsing from cold CLI startup without changing catalog order, matching, or public output.

Long-form explanation: docs/how-it-works.md. Formal model and robustness research program: docs/correlation.md.

JSON and Automation

recon <domain> --json emits a stable single-domain lookup object. Batch and delta modes emit different shapes, so route by mode or by record_type. Retained batch modes create at most the requested number of outer batch worker tasks while restoring input order. Each admitted lookup may still create its own bounded source tasks. --ndjson also releases completed records and remains the lowest-memory choice for large inputs. Batch processing is record-oriented: a valid run keeps exit code 0 when one or more domains fail. JSON and NDJSON consumers must inspect record_type and error_kind on every record; CSV consumers must inspect the error column. recon batch --summary --json preserves the separate aggregate-only cohort_summary 2.1 contract. New consumers can select --summary-schema 2.2 for raw-evidence-bound DMARC rates, corrected missingness, and explicit metric kinds. The standalone reducer uses --schema-version 2.2 for the corresponding atemporal compatibility view.

recon example.com --json
recon batch domains.txt --json
recon batch domains.txt --ndjson
recon delta example.com --json

Read these before building an integration:

• docs/schema.md: stable JSON contract.
• docs/recon-schema.json: machine-readable schema.
• docs/automation-examples.md: parser examples.
• docs/operational-contract.md: timeouts, bounds, exit codes, cache, and partial-result semantics.

docs/surface-inventory.json, docs/cli-surface.md, and recon://surface-inventory are generated discovery context and drift guards, not stable runtime API contracts. ADR-0007 records the promotion gate for any future stable subset.

MCP Server

The default install includes a local stdio MCP server for MCP-compatible tools. Start with manual approvals. Approval syntax is client-specific, and some current client schemas do not define autoApprove. Treat connected agents as untrusted input.

recon mcp install --client=claude-desktop
recon doctor --mcp
recon mcp doctor
recon doctor --client=claude-desktop

The three checks cover different boundaries in order: static server registry, live local stdio discovery plus canonical tool and JSON resource reads, then the named client's saved configuration. The live check does not inspect client configuration. The installer writes the right per-client config shape and preserves sibling MCP servers. Full setup, tool list, read-only versus stateful guidance, and troubleshooting live in docs/mcp.md. Per-client scaffolds live in agents/.

Limitations

The public channel has a ceiling:

• Internal-only workloads are invisible.
• SaaS products without DNS verification records may not appear.
• Email gateways can hide the downstream mailbox provider.
• CT logs can be stale, partial, rate-limited, or absent.
• Fingerprints are rule-based indicators, not proof of active use.

Read docs/limitations.md before using recon output for a high-stakes decision. Read docs/data-handling-policy.md before committing any validation artifact.

Documentation

• docs/getting-started.md: install, update, uninstall, and first commands.
• docs/how-it-works.md: readable model overview.
• docs/README.md: complete docs index.
• docs/roadmap.md: current plan, invariants, and scope boundaries.
• docs/structural-maintainability.md: measured source, test, compatibility, and facade cleanup plan.
• docs/external-writeup-plan.md: active maintainer plan for external write-up readiness.
• docs/submission-freeze-checklist.md: final paper and artifact freeze gate before any external submission package.
• docs/c3-ct-validation-plan.md: closed certificate-transparency validation plan.
• CHANGELOG.md: shipped changes.

Roadmap Focus

recon has a stable baseline, but product quality work remains. The top three priorities are:

1. Make every default claim traceable to evidence and remove product-use, cloud-type, or security-maturity conclusions that public metadata cannot support.
2. Keep the exact MCP v1.28.1 and v2.0.0b1 compatibility matrix green, then repeat the full gate against the final 2026-07-28 specification and stable v2 SDK before changing the production dependency.
3. Establish an aggregate-safe quality baseline for claim precision, abstention, provenance, catalog coverage, degradation, latency, CT value, and agent context cost before expanding inference or graph machinery.

Catalog coverage work uses deduplicated private rounds across rank, region, and domain-class strata. Real target names and per-domain records stay in ignored local validation workspaces. GitHub receives only generic provider patterns, provider-owned references, reserved synthetic fixtures, and disclosure-safe aggregates. The opt-in maintenance path now accounts separately for CNAME chains, apex CNAME, non-SPF TXT, SPF targets, MX, NS, CAA, DMARC RUA, bounded owner-qualified TXT, and bounded SRV observations. A frozen aggregate baseline and distinct sampling rounds are required before the project claims broad catalog coverage. The frozen convenience-sample baseline and a 366-namespace unseen vertical holdout are complete and public as aggregate counts only; independent rank, regional, vendor-seed, and drift rounds remain open.

The dependency order, acceptance evidence, stop rules, and current code-graph summary live in docs/roadmap.md. The concise execution sequence is the Quality Proof plan. The implementation plan is docs/engineering-refinement-plan.md, and the current step-back review is docs/strategic-gap-audit.md. Research publication, OpenSSF process, outside replication, and archive work remain separate maintainer tracks so they do not displace product truthfulness or measured utility.

The most recent completed historical local proof for the separate publication track is validation/2026-06-30-submission-freeze-local-proof.md. The current paper and artifact package is unfrozen after subsequent product, documentation, and release changes. Maintainers must rerun the submission gate before external submission. Its public-label decision keeps public lists as robustness checks rather than population rates, and its M365 tenancy decision keeps that evidence as corroboration rather than independent calibration.

Development

uv sync
uv run pre-commit install
uv run python scripts/release_readiness.py --allow-dirty
uv run python scripts/check.py

uv run python scripts/check.py is the canonical local gate. It runs lint, type checks, coverage-gated tests, fingerprint and generated-artifact checks, validation and added-line text hygiene, tracked Markdown link and heading-anchor validation, workflow and dependency-export guards, interface checks, paper claim and figure checks, and size/complexity ratchets. Its full-suite stage uses at most four file-grouped test workers while preserving combined branch coverage. Focused pytest commands stay serial by default. Do not push on --fast alone. CI and the release workflow pass an explicit Git revision range so text hygiene covers every added line in the pushed or release commit range, not only the final diff.

Release-shaped package builds use uv 0.11.17 and the exact hashed backend graph in build-constraints.txt. The build creates the sdist first and constructs the wheel from that file; the replay commands and remaining environment limits are documented in docs/supply-chain.md.

Project hygiene: keep examples reserved and synthetic, keep validation artifacts aggregate-only, and run uv run python scripts/check.py. The gate rejects the retired target-example vocabulary across public text while preserving provider definitions and ACME protocol terms; avoid dead code or placeholders. Contributor details: CONTRIBUTING.md.

License

Apache 2.0. Free to use, build on, fork, and share. See LICENSE for the full terms.