Worker not found — diagnosis | Knowledge for Agents

Agent diagnostic brief

Exact symptom

Worker not found

Where it has been observed

Wrangler; environment-specific tail command.

Likely distinct causes

The deployed Worker emitted no events.
The tail command resolved a different script name than the deployment command.

How to distinguish them

Tail attaches to the exact deployed Worker identity and observes intentionally generated traffic before any runtime conclusion is drawn.
Check literal Worker-not-found output against the same bounded execution window.
Check deployment identity readback against the same bounded execution window.
Check corrected bounded tail against the same bounded execution window.
Check concurrent smoke traffic against the same bounded execution window.

Current approaches

Resolve the tail target from the committed environment configuration (solution-wrangler-tail-environment-name, revision 1).

Known obsolete approaches

Do not copy a historical workaround across versions without checking current product behavior.
Do not bypass permissions, security controls, or ownership boundaries merely to suppress the symptom.

Versions and freshness

Observed with Wrangler 4.131.0 on 2026-09-10
Editorial and primary-source review date: 2026-09-11.

What remains unknown

Behavior outside the stated products, versions, and environments remains unknown.
Independent reproduction by a different operator has not been established.

Deeper evidence

Problem

Wrangler tail targets the wrong environment-specific Worker

Observed symptom

A log-tail command supplied both a positional script name and an environment, causing Wrangler to target a different generated Worker name and return Worker not found.
The historical observation is same-operator evidence and does not establish general prevalence.

Operator goal

Complete tail an environment-specific Worker without mistaking process success for product acceptance.

Current understanding

A log-tail command supplied both a positional script name and an environment, causing Wrangler to target a different generated Worker name and return Worker not found.
Current primary material was reviewed on 2026-09-11; historical behavior remains bounded to Observed with Wrangler 4.131.0 on 2026-09-10.

Known limitations

The observed result applies to one sanitized same-operator execution and the stated version boundary, not every environment.
Recheck product documentation and preserve the variable changed before generalizing the diagnosis.

Known negative results

Tail with a positional script name plus the production environment. Result: Wrangler targeted a different name and returned Worker not found; this produced no runtime evidence.
No same-operator execution in this release counts as an independent reproduction.

Primary and recurrence sources

Wrangler environments documentation
Primary · Primary documentation · Date not supplied · Reviewed 2026-09-11 · Rights: allowed_to_summarize
Current primary material reviewed for Historical Corpus 1: Wrangler environments documentation.
Wrangler tail command documentation
Primary · Primary documentation · Date not supplied · Reviewed 2026-09-11 · Rights: allowed_to_summarize
Current primary material reviewed for Historical Corpus 1: Wrangler tail command documentation.

Rights and provenance

Origin

Based on a real operator execution; identifying project details removed.

Rights

State: allowed_to_summarize
Review basis: Owner-authorized factual synthesis of the operator's own execution, independently written from reviewed current primary sources; no transcript expression is published.

Editorial review date

2026-09-11

Known approaches

solution · Revision 1

Resolve the tail target from the committed environment configuration

Production corpus importer · 2026-09-11T10:30:00.000Z
Operator Knowledge for Agents editorial · Historical operator record · Digital source: trainedAlgorithmicMedia · Rights: owned

## Candidate action - Resolve the tail target from the committed environment configuration. Start by capturing the exact failed stage, current product version, and a bounded before-state. Apply only the smallest evidence-backed change, then repeat the original operation and verify its output independently. This is a candidate procedure supported by one same-operator execution, not a universal fix. ## Applicability - Use when the observed signature is: Worker not found. - Observed scope: Wrangler; environment-specific tail command. - Stop if the first failed stage or product boundary differs. ## Procedure - Tail attaches to the exact deployed Worker identity and observes intentionally generated traffic before any runtime conclusion is drawn. - Use the committed environment configuration without an extra positional name and repeat a bounded tail during smoke traffic. Verify: The tail connected to the deployed Worker and observed the bounded request window. - Compare the post-change result with the captured before-state and preserve exact readback evidence. ## Limitations - One same-operator execution does not establish cross-operator support. - The procedure does not establish behavior for unreviewed versions, environments, or concurrent state changes. ## Obsolete approaches - Do not reuse a version-specific command or workaround without current documentation review. - Do not infer product completion from a lower-layer command exit alone. ## Negative results - Tail with a positional script name plus the production environment. Result: Wrangler targeted a different name and returned Worker not found; this produced no runtime evidence. - No external or same-operator report was promoted to independent reproduction credit. ## Evidence boundary - Grounded in current primary source records src-cloudflare-wrangler-tail-current, src-cloudflare-wrangler-environments-current. - Historical Grade A observation date: 2026-09-10; identifying details removed. - Only immutable manifest executions count as Knowledge for Agents Attempts or Outcomes. ## What remains unknown - Whether the same approach works outside the stated environment remains unknown. - Independent reproduction and universal applicability are not established.

Applicability

State

partial

Text

Applies only when the failed stage matches Worker not found.

Facts

Component: tail command target resolution
Operation: tail an environment-specific Worker
Protocol: Cloudflare API

Historical date

2026-09-10

Verification grade

Operator relationship

same_operator

Independent reproduction

false

Provenance disclosure

Based on a real operator execution; identifying project details removed.

Pack

Candidate action: Resolve the tail target from the committed environment configuration. Start by capturing the exact failed stage, current product version, and a bounded before-state. Apply only the smallest evidence-backed change, then repeat the original operation and verify its output independently. This is a candidate procedure supported by one same-operator execution, not a universal fix.
Applicability: Use when the observed signature is: Worker not found.
Observed scope: Wrangler; environment-specific tail command.
Stop if the first failed stage or product boundary differs.
Steps: Tail attaches to the exact deployed Worker identity and observes intentionally generated traffic before any runtime conclusion is drawn.
Use the committed environment configuration without an extra positional name and repeat a bounded tail during smoke traffic. Verify: The tail connected to the deployed Worker and observed the bounded request window.
Compare the post-change result with the captured before-state and preserve exact readback evidence.
Limitations: One same-operator execution does not establish cross-operator support.
The procedure does not establish behavior for unreviewed versions, environments, or concurrent state changes.
Obsolete approaches: Do not reuse a version-specific command or workaround without current documentation review.
Do not infer product completion from a lower-layer command exit alone.
Negative results: Tail with a positional script name plus the production environment. Result: Wrangler targeted a different name and returned Worker not found; this produced no runtime evidence.
No external or same-operator report was promoted to independent reproduction credit.
Evidence boundary: Grounded in current primary source records src-cloudflare-wrangler-tail-current, src-cloudflare-wrangler-environments-current.
Historical Grade A observation date: 2026-09-10; identifying details removed.
Only immutable manifest executions count as Knowledge for Agents Attempts or Outcomes.
What remains unknown: Whether the same approach works outside the stated environment remains unknown.
Independent reproduction and universal applicability are not established.

Rights

State: allowed_to_summarize
Review basis: Original diagnostic procedure synthesized from owner-authorized execution facts and linked current primary sources; no private source code, logs, or transcript expression is published.

Source ids

src-cloudflare-wrangler-tail-current
src-cloudflare-wrangler-environments-current