eCFR
Electronic Code of Federal Regulations including FAR, DFARS, and agency supplements. 13 tools.
| Endpoint | https://ecfr.1102tools.com/mcp (streamable-http) |
|---|---|
| Registry version | 1.1.13 |
| Now | 13 tools · grade D (55) · pin ts_aca9030a21d65d833ec77db722949b0e · protocol 2025-06-18 |
| First / last listed | 2026-10-24 21:13 UTC / 2026-10-24 21:13 UTC |
| Grade over time | 2026-10-24: D (55), 13 tools |
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Tools: get_latest_date get_cfr_content get_cfr_structure get_version_history get_ancestry search_cfr list_agencies get_corrections lookup_far_clause compare_versions list_sections_in_part find_far_definition find_recent_changes
get_latest_date | Get the most recent available date for a CFR title.
CRITICAL: eCFR lags 1-2 business days behind the Federal Register.
Using today's date on versioner endpoints causes 404 errors. Call this
first to get the safe date, then pass it to other tools.
Default title 48 = Federal Acquisition Regulations System (FAR, DFARS,
and all agency supplements). Other common titles: 2 (Grants/ params: title_number |
get_cfr_content | Get the full text of a CFR section, subpart, part, or appendix.
Returns parsed clean text by default: heading, paragraphs and citations, plus
tables, notes, examples, images, pending_amendments and editorial_notes
when present. Tables, notes and examples are numbered, and a marker like
"[See table 1: ...]" sits in the paragraphs where each appears. [fn N]
marks a footnote refe params: title_number, date, part, subpart, section, chapter, appendix, raw_xml, page |
get_cfr_structure | Get the hierarchical table of contents for a CFR title or subset.
Returns a nested tree of titles, chapters, parts, subparts, and sections
with identifiers, descriptions, and byte sizes, plus the date it
describes.
IMPORTANT: Does NOT support section-level filtering (returns 400).
Use part or subpart, then walk the children to find sections.
Common patterns:
- part=' params: title_number, date, chapter, subchapter, part, subpart, appendix, depth |
get_version_history | Get the version history of a CFR section, subpart, or part.
Returns content_versions (each with date, amendment_date, issue_date,
identifier, name, substantive and removed), every version eCFR lists:
all of eCFR's pages are read, so Part 52's 2,264 versions are all
there. Versions are grouped by section, oldest first.
since_date/until_date (YYYY-MM-DD) keep versions dated in params: title_number, part, section, subpart, since_date, until_date, per_page, page |
get_ancestry | Get the breadcrumb hierarchy path for a section, part, or appendix.
Returns ancestors from title down to the target node: title > chapter >
subchapter > part > subpart > section. Useful for understanding where
a section sits in the CFR hierarchy and what regulation it belongs to.
part/subpart/section/appendix accept int or string. The answer says
which date it describes.
params: title_number, date, part, section, appendix, subpart |
search_cfr | Full-text search across the Code of Federal Regulations.
Returns matching sections with excerpts, headings, scores, and hierarchy.
current_only=True (default) returns only text in effect now. eCFR's own
"current" index still lists some superseded and removed versions, so
each hit is checked against the section's version history: older
copies of a section are dropped, and hits params: query*, title, chapter, part, subpart, section, current_only, last_modified_after, last_modified_before, order, agency_slugs, per_page, page |
list_agencies | List all agencies with their CFR title and chapter references.
Returns agency names, slugs, and which CFR titles/chapters they own.
Useful for finding which chapter corresponds to an agency's FAR supplement.
summary_only (default True) strips the `children` and most of
`cfr_references` to keep the response compact (~20 KB vs ~100 KB).
References owned by child agencies are me params: summary_only |
get_corrections | Get editorial corrections for a CFR title, newest first.
Returns corrections with CFR references, corrective actions, error
dates, and FR citations, sorted by the date the error was corrected,
newest first. Useful for checking whether a section's current text has
been corrected since its last amendment.
section (e.g. '52.204-21'), part (e.g. '52') or chapter (e.g. '2' for
params: title_number, limit, since_year, section, part, chapter |
lookup_far_clause | Convenience tool: look up the current text of a FAR, DFARS or FAR supplement section or clause.
Pass a section identifier like '15.305', '52.212-4', '2.101',
'DFARS 252.204-7012' or '552.238-81'. The chapter comes from the number
(52.x = FAR, 252.x = DFARS, 552.x = GSAR, 852.x = VAAR, 1852.x = NFS,
3052.x = HSAR), so chapter is optional. Prefixes like 'FAR', 'DFARS',
'§' and ' params: section_id*, chapter, date, page |
compare_versions | Compare the text of a CFR section at two different dates.
Useful for understanding what changed in a regulatory amendment. Returns
'changes' (each paragraph that was added, removed or changed, with its
before and after text; also heading, table and pending-amendment-link
changes), 'identical' when nothing differs, and the parsed text at both
dates side by side. When both texts params: section_id*, date_before*, date_after*, title_number, chapter, changes_only |
list_sections_in_part | List all sections and appendices in a CFR part with their headings.
Returns 'sections' in order, each {identifier, heading}, with
type='appendix' on appendices (2 CFR 200's Appendix I-XII, for example)
and reserved=true on reserved sections, plus 'subparts' (each with its
heading, section_count and first and last section). Useful for seeing
the scope of a part before reading s params: part_number*, chapter, title_number, date, subpart, detail, page |
find_far_definition | Find a term's definition in FAR 2.101, the FAR's main definitions section.
Returns each matching definition whole (the defining paragraph and every
sub-paragraph under it), first, marked kind='definition'. Matching
ignores case, hyphens, spacing, plurals, a trailing "means", and the
acronym 2.101 puts in a name, so 'service-disabled veteran-owned small
business concern', 'SDVO params: term*, date, max_matches |
find_recent_changes | Find CFR sections changed since a given date, removals included.
Built on eCFR's version history: every version issued on or after
since_date, newest first. Each change says whether the section was
amended, removed (change='removed'), or re-issued with no text change
(substantive=false). 'summary' counts each kind. A section changed
twice appears twice.
since_date must be params: since_date*, title, chapter, part, per_page, page |
Entries describe changes in tool definitions. They are not statements about a server, its quality or its author. The grade measures how the tool definitions fit model providers (token cost, schema compatibility, confusable names) as scored by the ToolFit engine at the time of the listing. JSON: append .json. Opt-out: how or hello@youraitools.co.