redact-secret · Report

API key (re_)

re_ + 8 alphanumerics + _ + 24 alphanumerics, 36 in all; full_access and sending_access keys share the shape.

Resend
Detectors: resend-api-key
Run 2026-10-07
Mode published · redact-secret 0.1.0-beta.14

Dossier verdictReady
Dossier evidence levelT1 · Provider-documented
Dossier researched2026-09-28

Registry detector resend-api-key since redact-secret#915 (registry pinned at 1127bf9); graduated from a Beta.11 arrival family (#436), contract in benchmarks/lib/beta8/436d.ts. T1 on the provider CLI prefix and the docs/SDK example layout (R5); neither pinned scanner has a Resend rule.

New pipelineAuthority

Built from the new pipeline

The new pipeline is the authority for credential qualification. These numbers are read from the qualification view derived from the official credential-eval run of the public-evidence-snapshot population. The regression and policy populations keep their own counts on the qualification pages and are not added in here.

Authority: new
Population: public-evidence-snapshot
Engine: credential-eval 0.1.0-alpha.16
Evidence: snapshot-2026.10.06.4
Run: sha256:4bec6e539482…
Recorded: 2026-10-07
Authorised for: @redact-secret/core@0.1.0-beta.14

Maintainer-reviewed (independent review pending)

598 fixtures of the 7,041 in evidence release snapshot-2026.10.06.4 carry this label. They are counted in the numbers on this page.

Passed the project’s own verification (source evidence, automated checks, recorded counter-arguments); not yet independently reviewed.

OpenRedaction default (all patterns): not measured in this run (optional)

The default (all-pattern) profile is slow and noisy for credential evaluation: personal data and resource identifiers dominate its findings, and its last official measurement took 7 minutes of scanner time on a population the credential profile scans in seconds (its methods run takes 40+ minutes), so it is a manual measurement and never blocks other scanners or core verification (#763). Its earlier results stay as history with their run identity; the credential profile is a separate scanner, never spliced with it.

Last measurement: policy-corpus@linux-x64 (configuration sha256:2451ce7bf380), public-evidence-snapshot+methods@linux-x64 (configuration sha256:d47d081ce5fb), public-evidence-snapshot@linux-x64 (configuration sha256:2451ce7bf380), regression-corpus@linux-x64 (configuration sha256:2451ce7bf380) · engine 0.1.0-alpha.5 · recorded 2026-10-05 · retained record, no longer listed by the run registry. It stays labelled with that run identity and is never combined with another profile or another run.

Open the qualification page for this pointer

OpenRedaction credential profile (33 types): not measured in an official run (local exploratory diagnostics only: see ADR)

The credential profile is the comparison profile chosen in docs/decisions/2026-10-06-choose-the-openredaction-credential-bearing-profile-as-the-comparison-scanner.md. It is optional in the official run class because no pinned engine configuration measures it yet: making it required would refuse every official view until the owner approves the one profile-only run. Its own history starts with that run; nothing of the default's is reused for it.

No earlier measurement of it is recorded. Nothing is shown in its place.

Official measurement: pending: requires owner approval (one profile-only run; see the decision).

Open the qualification page for this pointer

Every population and its qualification

Research record

From credential-evidence snapshot-2026.10.06.4 · records at 77ce761 · schema 1.8.0. It describes the research on the format, not what any scanner or the product does, and not a support status.

Review stateDraft, not reviewed
Format revision1 · current
ResearchResearched
Researched2026-09-28

3 events in the review history: 2 observed, 1 reviewed. Latest: observed on 2026-09-28 by automation, project maintainer. Project-maintained review is not independent validation. The family record at this release.

Format

Provider format research from credential-evidence snapshot-2026.10.06.4 · records at 77ce761 · schema 1.8.0.

What it looks like

Descriptive pattern: ^re_[A-Za-z0-9]{8}_[A-Za-z0-9]{24}$

Parts are shown as recorded. Evidence classes belong to the facts below; no class is assigned to a part.

Format facts

Provider documented · provider-source · current · observed 2026-09-28
resend-cli login rejects a key that does not start with re_; the create-API-key response example is re_ + 8 + _ + 24 (re-checked 2026-09-28: 36 characters, no 0/O/I/l): re_ + 8 alphanumerics + _ + 24 alphanumerics, 36 in all; full_access and sending_access keys share the shape
- resend.com/docs/api-reference/api-keys/create-api-keyprovider-documentation · last read 2026-09-28 · latest outcome read · supports re_ + 8 alphanumerics + _ + 24 alphanumerics, 36 in all; full_access and sending_access keys share the shape
Provider documented · field-prefix · current · observed 2026-09-28
prefix: re_
- github.com/resend/resend-cliprovider-sdk-source · last read 2026-09-28 · latest outcome read · supports "Your key must start with re_" · #authentication
Provider documented · field-layout · current · observed 2026-09-28
layout: re_ + 8 + _ + 24 (36 in all); the _ at offset 11 is the only one after the prefix
- redact-secret/redact-secret @ 54fe385f718c884d7e3dde6b9756e2d70999ca91: docs/audits/evidence/860/resend.mdprovider-documentation · last read 2026-09-28 · latest outcome read · supports the same shape in three distinct SDK fixture values
- github.com/redact-secret/redact-secret/issues/860issue-or-discussion · last read 2026-09-29 · latest outcome read · supports R5 · #issuecomment-5871306275
- resend.com/docs/api-reference/api-keys/create-api-keyprovider-documentation · last read 2026-09-28 · latest outcome read · supports response example, measured by script, no value retained
Provider documented · field-alphabet · current · observed 2026-09-28
alphabet: [A-Za-z0-9] in both segments (Every provider example is alphanumeric and base58-consistent; the contract keeps the alphanumeric superset, so a key with 0, O, I or l is not a false negative.)
- redact-secret/redact-secret @ 54fe385f718c884d7e3dde6b9756e2d70999ca91: docs/audits/evidence/860/resend.mdprovider-documentation · last read 2026-09-28 · latest outcome read · supports a trufflehog rule newer than the pinned 3.97.4 uses base58, a narrower class
- resend.com/docs/api-reference/api-keys/create-api-keyprovider-documentation · last read 2026-09-28 · latest outcome read · supports alphabet: [A-Za-z0-9] in both segments
Unresolved · field-mixed-case-guard · current · observed 2026-09-28
mixed-case-guard: the product requires at least one upper- and one lower-case letter in the 32 body bytes (Project false-positive policy, not a provider fact. Positives are mixed case; no fixture asserts silence on a random one-case body, and the one-case controls are word-built identifiers.)
- redact-secret/redact-secret @ 54fe385f718c884d7e3dde6b9756e2d70999ca91: docs/audits/evidence/860/resend.mdprovider-documentation · last read 2026-09-28 · latest outcome read · supports the short-prefix guard; false-negative cost about 6e-8
Provider documented · field-transport · current · observed 2026-09-28
transport: the RESEND_API_KEY environment variable, sent as Authorization: Bearer
- resend.com/docs/api-reference/introductionprovider-documentation · last read 2026-09-28 · latest outcome read · supports transport: the RESEND_API_KEY environment variable, sent as Authorization: Bearer · #authentication
Provider documented · field-webhook-secret · current · observed 2026-09-28
webhook-secret: whsec_ webhook signing secrets use the Svix scheme (Another credential class: a prefix twin, never a benign control.)
- redact-secret/redact-secret @ 54fe385f718c884d7e3dde6b9756e2d70999ca91: docs/audits/evidence/860/resend.mdprovider-documentation · last read 2026-09-28 · latest outcome read · supports excluded shapes
Tool corroborated · field-peer-lag · current · observed 2026-09-28
peer-lag: no rule in trufflehog 3.97.4 or gitleaks 8.30.1
- gitleaks/gitleaks @ v8.30.1: config/gitleaks.tomlscanner-rule-source · last read 2026-10-04 · latest outcome read · supports no resend rule
- trufflesecurity/trufflehog @ v3.97.4: pkg/detectorsscanner-rule-source · last read 2026-09-29 · latest outcome read · supports no resend detector directory at the pinned version
Unresolved · listed-references · current · observed 2026-09-28
The legacy contract lists 9 references without stating which property each supports.
- redact-secret/redact-secret @ 54fe385f718c884d7e3dde6b9756e2d70999ca91: docs/audits/evidence/860/resend.mdprovider-documentation · last read 2026-09-28 · latest outcome read · supports Listed as a reference by the legacy contract
- redact-secret/redact-secret @ 54fe385f718c884d7e3dde6b9756e2d70999ca91: docs/audits/evidence/860/tier-b-rerank.mdproject-research-note · last read 2026-09-28 · latest outcome read · supports Listed as a reference by the legacy contract
- github.com/redact-secret/redact-secret/issues/860issue-or-discussion · last read 2026-09-29 · latest outcome read · supports Listed as a reference by the legacy contract · #issuecomment-5871306275
- github.com/redact-secret/redact-secret/issues/860issue-or-discussion · last read 2026-09-29 · latest outcome read · supports Listed as a reference by the legacy contract
- github.com/redact-secret/redact-secret-benchmarks/issues/436issue-or-discussion · last read 2026-09-28 · latest outcome read · supports Listed as a reference by the legacy contract
- github.com/redact-secret/redact-secret/issues/915issue-or-discussion · last read 2026-09-28 · latest outcome read · supports Listed as a reference by the legacy contract
- github.com/resend/resend-cliprovider-sdk-source · last read 2026-09-28 · latest outcome read · supports Listed as a reference by the legacy contract · #authentication
- resend.com/docs/api-reference/introductionprovider-documentation · last read 2026-09-28 · latest outcome read · supports Listed as a reference by the legacy contract · #authentication
- resend.com/docs/api-reference/api-keys/create-api-keyprovider-documentation · last read 2026-09-28 · latest outcome read · supports Listed as a reference by the legacy contract
Provider documented · dossier-research · current · observed 2026-09-28
Legacy dossier research (verdict ready, tier T1) cited 3 sources; the dossier does not attribute sources to individual properties.
- redact-secret/redact-secret @ 8b6a5fde52ecb4dfce13f09c7a947062d21483c7: docs/audits/evidence/860/resend.mdproject-research-note · last read 2026-09-28 · latest outcome read · supports Final research evidence recorded by the legacy dossier
- github.com/resend/resend-cliprovider-sdk-source · last read 2026-09-28 · latest outcome read · supports Cited by the legacy dossier research for this family · #authentication
- resend.com/docs/api-reference/api-keys/create-api-keyprovider-documentation · last read 2026-09-28 · latest outcome read · supports Cited by the legacy dossier research for this family
Provider documented · taxonomy-sources · current · observed 2026-09-28
The legacy taxonomy lists 2 sources for this family. The taxonomy records no date; the dossier researchedAt is used as the observed-at date.
- github.com/resend/resend-cliprovider-sdk-source · last read 2026-09-28 · latest outcome read · supports Listed as a source for this family in the legacy taxonomy · #authentication
- resend.com/docs/api-reference/api-keys/create-api-keyprovider-documentation · last read 2026-09-28 · latest outcome read · supports Listed as a source for this family in the legacy taxonomy

Open questions

No open question is recorded for this revision.

Benchmark dossier notes

From the provider dossier, as written. The evidence level above says how well the format is backed; a fact the dossier does not record is not shown.

Shape: prefix re_, then 8 characters, an underscore, and 24 characters (36 in total), alphanumeric in both segments.
Basis: prefix T1: the provider CLI rejects a key that does not start with re_ ("Your key must start with re_"). The 8 + _ + 24 layout is T1 by example under ruling R5: the create-API-key docs example, plus provider SDK fixtures (three distinct values across the Go, Python, Node and .NET SDKs). The live docs example was re-measured on 2026-09-28. The three samples are consistent with base58, but three samples show what is present, not what is excluded, so the handoff takes the alphanumeric superset (the #655 Entra precedent).
Issuance: not attempted.
Contract in core: detector-families.md.

In this benchmark

Fixture rows on the current run. Counts are for redact-secret in published · redact-secret 0.1.0-beta.14 mode.

Fixtures: 42
Left readable: 0
Redacted too much: 0
False alarms: 0

42 fixtures: 17 expect a redaction, 25 must stay quiet. See every row

redact-secret fixture counts by evidence level
Evidence level	Fixtures	Left readable	Too much	False alarms
T1Provider-documented	17	0	0	0
T2Tool-corroborated	16	0	0	0
T3Project policy	9	0	0	0

Every scanner on the same fixtures

In run order. Counts are what each scanner recorded on this family's fixtures, whichever rules it has; a scanner with no rule for the family has nothing to report on it.

Counts per scanner on this family's fixtures
Scanner	Fixtures	Left readable	Too much	False alarms
flare-redactRuntime library · 1.6.1 · Published npm package · secrets-only (pii, generic_assignment disabled) · JavaScript engineNo rule maps to it	42	15	2	1
gitleaksRepository scanner · 8.30.1 · Directory scan · default rulesNo rule maps to it	42	8	0	2
redact-secretProduct measured here · 0.1.0-beta.14 · Published npm package · default detectors1 detector mapped	42	0	0	0
trufflehogRepository scanner · 3.97.4 · Filesystem scan · verification disabledNo rule maps to it	42	17	0	0

Benchmark dossier questions

Things the sources do not settle. They are listed so nobody reads them as settled.

Open caveat: Segment layout and length rest on provider examples and SDK fixtures (R5), not a stated grammar; the alphanumeric superset was chosen deliberately over the base58 seen in samples.

Looks like it, but isn't

Values the dossier records as resembling this credential without being one.

Collisions: re_ is very short and ends many identifiers and Python names; the leading boundary removes glued cases and the handoff adds a mixed-case post check (false-negative cost about 6e-8). No other issuer using re_ was found.

Scanner rules for this family

Mapped by hand (reviewed 2026-09-30) from each scanner's pinned rule file, never from what a scanner found on the fixtures.

No peer rule maps to this family

None of the reviewed peer scanners has a rule that can match a credential of this family.

None mapped

Find

Evidence level

Scanners

42 of 42 rows

Fixtures in this family

42 rows, redact-secret's outcome on each. Rows that need a look come first (0), then the rest in corpus order. Choose "Every scanner" to see each scanner's outcome for the same rows.

Fixtures in API key (re_)
Fixture	Kind and evidence	redact-secret
`resend-api-key-bare-prose`resend · documented-format-literal	Must redactT1 · Provider-documented	Redacted
`resend-api-key-bearer-header`resend · documented-format-literal	Must redactT1 · Provider-documented	Redacted
`resend-api-key-chat-paste`resend · documented-format-literal	Must redactT1 · Provider-documented	Redacted
`resend-api-key-compose-env`resend · documented-format-literal	Must redactT1 · Provider-documented	Redacted
`resend-api-key-curl-bearer`resend · documented-format-literal	Must redactT1 · Provider-documented	Redacted
`resend-api-key-digits-placeholder`resend · documentation-placeholder	Must not flagT3 · Project policy	Quiet
`resend-api-key-dotenv`resend · documented-format-literal	Must redactT1 · Provider-documented	Redacted
`resend-api-key-export`resend · documented-format-literal	Must redactT1 · Provider-documented	Redacted
`resend-api-key-json-api-key`resend · documented-format-literal	Must redactT1 · Provider-documented	Redacted
`resend-api-key-json-token`resend · documented-format-literal	Must redactT1 · Provider-documented	Redacted
`resend-api-key-key-shape-bare`resend · documented-format-literal	Must redactT1 · Provider-documented	Redacted
`resend-api-key-key-shape-quoted`resend · documented-format-literal	Must redactT1 · Provider-documented	Redacted
`resend-api-key-key-shape-unicode-crlf`resend · documented-format-literal	Must redactT1 · Provider-documented	Redacted
`resend-api-key-mcp-env`resend · documented-format-literal	Must redactT1 · Provider-documented	Redacted
`resend-api-key-python-module`resend · documented-format-literal	Must redactT1 · Provider-documented	Redacted
`resend-api-key-sdk-kwarg`resend · documented-format-literal	Must redactT1 · Provider-documented	Redacted
`resend-api-key-trailing-glue-twin`resend · boundary-violation	Must not flagT2 · Tool-corroborated · twin	Quiet
`resend-api-key-ts-client`resend · documented-format-literal	Must redactT1 · Provider-documented	Redacted
`resend-api-key-webhook-secret-twin`resend · prefix-near-miss	Must not flagT2 · Tool-corroborated · twin	Quiet
`resend-api-key-x-api-key-header`resend · documented-format-literal	Must redactT1 · Provider-documented	Redacted
`resend-api-key-are-glue-twin`resend · boundary-violation	Must not flagT2 · Tool-corroborated · twin	Quiet
`resend-api-key-env-reference-reference`resend · templated-reference	Must not flagT3 · Project policy	Quiet
`resend-api-key-hyphen-separator-twin`resend · boundary-violation	Must not flagT2 · Tool-corroborated · twin	Quiet
`resend-api-key-key-guidance-prose`resend · prose-mention	Must not flagT3 · Project policy	Quiet
`resend-api-key-label-prose`resend · benign-lookalike	Must not flagT3 · Project policy	Quiet
`resend-api-key-mask`resend · benign-lookalike	Must not flagT3 · Project policy	Quiet
`resend-api-key-masked-placeholder`resend · documentation-placeholder	Must not flagT3 · Project policy	Quiet
`resend-api-key-pre-identifier-public-id`resend · public-identifier	Must not flagT2 · Tool-corroborated	Quiet
`resend-api-key-prefix-only`resend · benign-lookalike	Must not flagT2 · Tool-corroborated	Quiet
`resend-api-key-python-re-names-public-id`resend · public-identifier	Must not flagT2 · Tool-corroborated	Quiet
`resend-api-key-reference`resend · benign-lookalike	Must not flagT3 · Project policy	Quiet
`resend-api-key-second-underscore-twin`resend · wrong-alphabet	Must not flagT2 · Tool-corroborated · twin	Quiet
`resend-api-key-segment1-7-twin`resend · wrong-length	Must not flagT2 · Tool-corroborated · twin	Quiet
`resend-api-key-segment1-9-twin`resend · wrong-length	Must not flagT2 · Tool-corroborated · twin	Quiet
`resend-api-key-segment2-23-twin`resend · wrong-length	Must not flagT2 · Tool-corroborated · twin	Quiet
`resend-api-key-segment2-25-twin`resend · wrong-length	Must not flagT2 · Tool-corroborated · twin	Quiet
`resend-api-key-short-body`resend · benign-lookalike	Must not flagT2 · Tool-corroborated	Quiet
`resend-api-key-truncated-near-miss`resend · format-near-miss	Must not flagT2 · Tool-corroborated	Quiet
`resend-api-key-underscore-glue-twin`resend · boundary-violation	Must not flagT2 · Tool-corroborated · twin	Quiet
`resend-api-key-uppercase-prefix-twin`resend · prefix-near-miss	Must not flagT2 · Tool-corroborated · twin	Quiet
`resend-api-key-x-run-placeholder`resend · documentation-placeholder	Must not flagT3 · Project policy	Quiet
`resend-api-key-your-key-placeholder`resend · documentation-placeholder	Must not flagT3 · Project policy	Quiet

Sources

Researched 2026-09-28.

Documentation and code

resend.com/docs/api-reference/api-keys/create-api-key
github.com/resend/resend-cli#authentication

Research log

redact-secret/redact-secret#860Research issue
redact-secret/redact-secret#915Research issue
redact-secret/redact-secret-benchmarks#436Research issue
Final evidence, pinned to a commit/redact-secret/redact-secret/blob/8b6a5fde52ecb4dfce13f09c7a947062d21483c7/docs/audits/evidence/860/resend.md