Use this skill whenever the user mentions IP geolocation feeds, RFC 8805, geofeeds, or wants help creating, tuning, validating, or publishing a self-published IP geolocation feed in CSV format. Intended user audience is a network operator, ISP, mobile carrier, cloud provider, hosting company, IXP, o

Geofeed Tuner – Create Better IP Geolocation Feeds This skill helps you create and improve IP geolocation feeds in CSV format by: Ensuring your CSV is well formed and consistent Checking alignment with [RFC 8805](references/rfc8805.txt) (the industry standard) Applying opinionated best practices learned from real world deployments Suggesting improvements for accuracy, completeness, and privacy When to Use This Skill Use this skill when a user asks for help creating, improving, or publishing an IP geolocation feed file in CSV format. Use it to tune and troubleshoot CSV geolocation feeds — catching errors, suggesting improvements, and ensuring real world usability beyond RFC compliance. Intended audience: Network operators, administrators, and engineers responsible for publicly routable IP address space Organizations such as ISPs, mobile carriers, cloud providers, hosting and colocation companies, Internet Exchange operators, and satellite internet providers Do not use this skill for private or internal IP address management; it applies only to publicly routable IP addresses . Prerequisites Python 3 is required. Directory Structure and File Management This skill uses a clear separation between distribution files (read only) and working files (generated at runtime). Read Only Directories (Do Not Modify) The following directories contain static distribution assets. Do not create, modify, or delete files in these directories: Directory Purpose assets/ Static data files (ISO codes, examples) references/ RFC specifications and code snippets for reference scripts/ Executable code and HTML template files for reports Working Directories (Generated Content) All generated, temporary, and output files go in these directories: Directory Purpose run/ Working directory for all agent generated content run/data/ Downloaded CSV files from remote URLs run/report/ Generated HTML tuning reports File Management Rules 1. Never write to assets/ , references/ , or scripts/ — these are part of the skill distribution and must remain unchanged. 2. All downloaded input files (from remote URLs) must be saved to ./run/data/ . 3. All generated HTML reports must be saved to ./run/report/ . 4. All generated Python scripts must be saved to ./run/ . 5. The run/ directory may be cleared between sessions; do not store permanent data there. 6. Working directory for execution: All generated scripts in ./run/ must be executed with the skill root directory (the directory containing SKILL.md ) as the current working directory, so that relative paths like assets/iso3166 1.json and ./run/data/report data.json resolve correctly. Do not cd into ./run/ before running scripts. Processing Pipeline: Sequential Phase Execution All phases must be executed in order , from Phase 1 through Phase 6. Each phase depends on the successful completion of the previous phase. For example, structure checks must complete before quality analysis can run. The phases are summarized below. The agent must follow the detailed steps outlined further in each phase section. Phase Name Description 1 Understand the Standard Review the key requirements of RFC 8805 for self published IP geolocation feeds 2 Gather Input Collect IP subnet data from local files or remote URLs 3 Checks & Suggestions Validate CSV structure, analyze IP prefixes, and check data quality 4 Tuning Data Lookup Use Fastah's MCP tool to retrieve tuning data for improving geolocation accuracy 5 Generate Tuning Report Create an HTML report summarizing the analysis and suggestions 6 Final Review Verify consistency and completeness of the report data Do not skip phases. Each phase provides critical checks or data transformations required by subsequent stages. Execution Plan Rules Before executing each phase, the agent MUST generate a visible TODO checklist. The plan MUST: Appear at the very start of the phase List every step in order Use a checkbox format Be updated live as steps complete Phase 1: Understand the Standard The key requirements from RFC 8805 that this skill enforces are summarized below. Use this summary as your working reference. Only consult the full [RFC 8805 text](references/rfc8805.txt) for edge cases, ambiguous situations, or when the user asks a standards question not covered here. RFC 8805 Key Facts Purpose: A self published IP geolocation feed lets network operators publish authoritative location data for their IP address space in a simple CSV format, allowing geolocation providers to incorporate operator supplied corrections. CSV Column Order (Sections 2.1.1.1–2.1.1.5): Column Field Required Notes 1 ip prefix Yes CIDR notation; IPv4 or IPv6; must be a network address 2 alpha2code No ISO 3166 1 alpha 2 country code; empty or "ZZ" = do not geolocate 3 region No ISO 3166 2 subdivision code (e.g., US CA ) 4 city No Free text city name; no authoritative validation set 5 postal code No Deprecated — must be left empty or absent Structural rules: Files may contain comment lines beginning with (including the header, if present). A header row is optional; if present, it is treated as a comment if it starts with . Files must be encoded in UTF 8. Subnet host bits must not be set (i.e., 192.168.1.1/24 is invalid; use 192.168.1.0/24 ). Applies only to globally routable unicast addresses — not private, loopback, link local, or multicast space. Do not geolocate: An entry with an empty alpha2code or case insensitive ZZ (irrespective of values of region/city) is an explicit signal that the operator does not want geolocation applied to that prefix. Postal codes deprecated (Section 2.1.1.5): The fifth column must not contain postal or ZIP codes. They are too fine grained for IP range mapping and raise privacy concerns. Phase 2: Gather Input If the user has not already provided a list of IP subnets or ranges (sometimes referred to as inetnum or inet6num ), prompt them to supply it. Accepted input formats: Text pasted into the chat A local CSV file A remote URL pointing to a CSV file If the input is a remote URL : Attempt to download the CSV file to ./run/data/ before processing. On HTTP error (4xx, 5xx, timeout, or redirect loop), stop immediately and report to the user: Feed URL is not reachable: HTTP {status code}. Please verify the URL is publicly accessible. Do not proceed to Phase 3 with an incomplete or empty download. If the input is a local file , process it directly without downloading. Encoding detection and normalization: 1. Attempt to read the file as UTF 8 first. 2. If a UnicodeDecodeError is raised, try utf 8 sig (UTF 8 with BOM), then latin 1 . 3. Once successfully decoded, re encode and write the working copy as UTF 8. 4. If no encoding succeeds, stop and report: Unable to decode input file. Please save it as UTF 8 and try again. Phase 3: Checks & Suggestions Execution Rules Generate a script for this phase. Do NOT combine this phase with others. Do NOT precompute future phase data. Store the output as a JSON file at: ./run/data/report data.json Schema Definition The JSON structure below is IMMUTABLE during Phase 3. Phase 4 will later add a TunedEntry object to each object in Entries — this is the only permitted schema extension and happens in a separate phase. JSON keys map directly to template placeholders like {{.CountryCode}} , {{.HasError}} , etc. Field definitions: Top level metadata: InputFile : The original input source, either a local filename or a remote URL. Timestamp : Milliseconds since Unix epoch when the tuning was performed. TotalEntries : Total number of data rows processed (excluding comment and blank lines). IpV4Entries : Count of entries that are IPv4 subnets. IpV6Entries : Count of entries that are IPv6 subnets. InvalidEntries : Count of entries that failed IP prefix parsing and CSV parsing. Errors : Total entries whose Status is ERROR . Warnings : Total entries whose Status is WARNING . OK : Total entries whose Status is OK . Suggestions : Total entries whose Status is SUGGESTION . CityLevelAccuracy : Count of valid entries where City is non empty. RegionLevelAccuracy : Count of valid entries where RegionCode is non empty and City is empty. CountryLevelAccuracy : Count of valid entries where CountryCode is non empty, RegionCode is empty, and City is empty. DoNotGeolocate (metadata): Count of valid entries where CountryCode , RegionCode , and City are all empty. Entry fields: Entries : Array of objects, one per data row, with the following per entry fields: Line : 1 based line number in the original CSV (counting all lines including comments and blanks). IPPrefix : The normalized IP prefix in CIDR slash notation. CountryCode : The ISO 3166 1 alpha 2 country code, or empty string. RegionCode : The ISO 3166 2 region code (e.g., US CA ), or empty string. City : The city name, or empty string. Status : Highest severity assigned: ERROR WARNING SUGGESTION OK . IPVersion : "IPv4" or "IPv6" based on the parsed IP prefix. Messages : Array of message objects, each with: ID : String identifier from the Validation Rules Reference table below (e.g., "1101" , "3301" ). Type : The severity type: "ERROR" , "WARNING" , or "SUGGESTION" . Text : The human readable validation message string. Checked : true if the validation rule is auto tunable ( Tunable: true in the reference table), false otherwise. Controls whether the checkbox in the report is checked or disabled . HasError : true if any message has Type "ERROR" . HasWarning : true if any message has Type "WARNING" . HasSuggestion : true if any message has Type "SUGGESTION" . DoNotGeolocate (entry): true if CountryCode is empty or "ZZ" — the entry is an explicit do not geolocate signal. GeocodingHint : Always empty string "" in Phase 3. Reserved for future use. Tunable : true if any message in the entry has Checked: true . Computed as logical OR across all messages' Checked values. This flag drives the "Tune" button visibility in the report. Validation Rules Reference When adding messages to an entry, use the ID , Type , Text , and Checked values from this table. ID Type Text Checked Condition Reference 1101 ERROR IP prefix is empty false IP Prefix Analysis: empty 1102 ERROR Invalid IP prefix: unable to parse as IPv4 or IPv6 network false IP Prefix Analysis: invalid syntax 1103 ERROR Non public IP range is not allowed in an RFC 8805 feed

geofeed-tuner