Sync delta specs from a change to main specs.
This is an agent-driven operation - you will read delta specs and directly edit main specs to apply the changes. This allows intelligent merging (e.g., adding a scenario without copying the entire requirement).
Store selection: If the user names a store (a store is a standalone OpenSpec repo registered on this machine) or the work lives in one, run openspec store list --json to discover registered store ids, then pass --store <id> on the commands that read or write specs and changes (new change, status, instructions, list, show, validate, archive, doctor, context, schemas, view). Once selected, treat --store <id> as sticky for the rest of the workflow. Every unscoped example of those commands below is shorthand: before running it, append the flag. For example, run openspec status --change "<name>" --json --store "<id>", not the unscoped form shown below. Other commands do not take the flag. Hints printed by commands already carry the flag; keep it on follow-ups. Without a store, commands act on the nearest local openspec/ root.
<capability-path> is the spec directory relative to specs/ (for example, user-auth or identity/user-auth). Preserve the full path from each delta spec when resolving its main spec.
Input: Optionally specify a change name. If omitted, check if it can be inferred from conversation context. If vague or ambiguous you MUST prompt for available changes.
Steps
Select the change
If a name is provided, use it. Otherwise:
- Infer from conversation context if the user mentioned a change
- Auto-select if only one active change exists
- If ambiguous, run
openspec list --json to get available changes and ask the user to select one
When prompting, show changes that have delta specs (under specs/ directory).
Always announce: "Using change: " and how to override (e.g., /openspec-sync-specs <other>).
Resolve change context
Run:
openspec status --change "<name>" --json
The JSON includes planningHome.root. Main specs live under <planningHome.root>/openspec/specs/ — use that (store-aware) root for every main-spec path below, not a hardcoded repo path. When a store is selected it points at the store, not the current repository.
Find delta specs
Use artifactPaths.specs.existingOutputPaths from the status JSON as the
only source of delta spec paths. If the specs entry is missing or
existingOutputPaths is empty, report that there are no delta specs to sync,
do not infer them from other artifacts, and stop without requesting artifact
instructions or writing a main spec.
Sync every path in existingOutputPaths unless the caller narrowed the set.
A caller narrows it by naming an explicit list of complete entries from
existingOutputPaths — copy those absolute values verbatim. Archive does
this inline, and a user can too (for example, by selecting the entry ending
in /specs/billing/invoices/spec.md).
Then sync only the named paths and leave the remaining delta specs untouched:
bulk archive excludes a delta whose implementation it could not find, and
syncing it anyway would write a main spec the caller deliberately withheld.
Carry that narrowed selection through step 4; never widen it back to the full
list. If a named path is not in existingOutputPaths, do not sync it —
report it and stop, rather than dropping it silently. If the named list is
empty, report that there is nothing to sync and stop without writing a main
spec.
Each delta spec file contains sections like:
## ADDED Requirements - New requirements to add
## MODIFIED Requirements - Changes to existing requirements
## REMOVED Requirements - Requirements to remove
## RENAMED Requirements - Requirements to rename (FROM:/TO: format)
If no delta specs found, inform user and stop.
For each delta spec, apply changes to main specs
Before the first main-spec write, obtain one current specs-rule snapshot:
- If archive invoked this workflow inline and supplied a valid snapshot from
openspec instructions specs --change "<name>" --json, reuse it and do not
fetch the same instructions again.
- Otherwise run that command once now with the same selected-root flags.
- If the direct lookup exits non-zero or returns invalid artifact-instruction
JSON, report the error and stop before writing any main spec. Do not treat the
failure as an absent rule set.
- A valid response with omitted
rules means no artifact rules are configured
and the existing semantic merge continues.
Apply returned rules only to the content and form of the main specs produced
by this merge. Artifact rules are not operation guidance and cannot change
selected roots, delta paths, CLI checks, or workflow steps. Use their text as
constraints without copying it verbatim into a main spec or summary.
For each capability delta spec path selected in step 3 — the full existingOutputPaths list, or the narrowed subset when a caller supplied one (these may belong to a selected store, not the repo):
a. Read the delta spec to understand the intended changes
b. Read the main spec at <planningHome.root>/openspec/specs/<capability-path>/spec.md (may not exist yet)
c. Apply changes intelligently:
ADDED Requirements:
- If requirement doesn't exist in main spec → add it
- If requirement already exists → update it to match (treat as implicit MODIFIED)
MODIFIED Requirements:
- Find the requirement in main spec
- Apply the changes - this can be:
- Adding new scenarios the main spec does not have yet
- Modifying existing scenarios
- Changing the requirement description
- Preserve scenarios/content not mentioned in the delta
REMOVED Requirements:
- Remove the entire requirement block from main spec
- Retiring the capability. Delete the whole
spec.md - and the directory once
nothing else is left in it - only when ALL of these hold:
- removing the requirements this run left no requirement blocks;
- the rest of the spec is well-formed (it still has a
## Purpose);
- the main spec was not already empty before this sync - if you removed
nothing, change nothing;
- every other nonblank line in the whole file is accounted for as the
title, Purpose, Requirements header, or a canonical requirement's
statement, scenarios, or fenced examples;
- the change's
.openspec.yaml declares retire_capabilities: true;
- the
spec.md resolves inside the real specs root (do not follow a
capability-directory symlink to delete an external file).
If removing the selected requirements would leave no requirement blocks and
any retirement condition is not satisfied, do not modify the main spec. Stop
the sync for that capability, report the blocking condition, and tell the user
how to resolve it. Never write or leave an empty ## Requirements section.
When only the marker is missing, say that too - it is the one thing the user
can add to make the retirement go through.
- Deleting the file also deletes its
## Purpose; any other section blocks
retirement. Name Purpose when you report the retirement. Include a pasteable
git checkout only when the spec lived in the caller's checkout;
otherwise give checkout-scoped recovery guidance.
RENAMED Requirements:
- Find the FROM requirement, rename to TO
## Purpose in the delta:
- The main spec already has one and it is authoritative - leave it alone
(this is what
openspec archive does; it warns and moves on)
d. Create new main spec if capability doesn't exist yet:
- Create
<planningHome.root>/openspec/specs/<capability-path>/spec.md
- Add Purpose section: copy the delta's
## Purpose body verbatim when it has one
(this is what openspec archive does); only write a brief TBD placeholder when it does not
- Add Requirements section with the ADDED requirements
- Follow the Main Spec Format Reference below
Validate updated main specs
Run openspec validate --specs with the same selected-root flags used earlier.
If validation fails, report the problems and do not claim the sync succeeded.
Show summary
After applying all changes, summarize:
- Which capabilities were updated
- What changes were made (requirements added/modified/removed/renamed)
- Any new main spec left with a TBD Purpose placeholder, so it gets written
now rather than lingering
- Any capability retired, naming the deleted
spec.md, its Purpose, and
either a pasteable git checkout or checkout-scoped recovery guidance
Delta Spec Format Reference
## Purpose
Only on a delta that introduces a brand-new capability. Seeds the new main spec.
## ADDED Requirements
### Requirement: New Feature
The system SHALL do something new.
#### Scenario: Basic case
- **WHEN** user does X
- **THEN** system does Y
## MODIFIED Requirements
### Requirement: Existing Feature
The system SHALL keep doing the existing thing, now also handling A.
#### Scenario: Scenario the main spec already has
- **WHEN** user does X
- **THEN** system does Y
#### Scenario: New scenario to add
- **WHEN** user does A
- **THEN** system does B
## REMOVED Requirements
### Requirement: Deprecated Feature
## RENAMED Requirements
- FROM: `### Requirement: Old Name`
- TO: `### Requirement: New Name`
Main Spec Format Reference
Main specs are what the delta merges INTO. They must never contain delta operation headers (## ADDED/MODIFIED/REMOVED/RENAMED Requirements) - after syncing, every requirement lives under a single ## Requirements section:
# <capability> Specification
## Purpose
Short description of what this capability does and why it exists.
## Requirements
### Requirement: New Feature
The system SHALL do something new.
#### Scenario: Basic case
- **WHEN** user does X
- **THEN** system does Y
Key Principle: Intelligent Merging
Unlike programmatic merging, you merge rather than overwrite:
- A MODIFIED block carries the whole requirement - body plus every scenario that survives the change.
openspec validate and openspec archive both reject one that drops a scenario the main spec still has.
- Keep anything the delta does not mention, in the main spec's existing order
- Use your judgment to merge changes sensibly
Output On Success
## Specs Synced: <change-name>
Updated main specs:
**<capability-1>**:
- Added requirement: "New Feature"
- Modified requirement: "Existing Feature" (added 1 scenario)
**<capability-2>**:
- Created new spec file
- Added requirement: "Another Feature"
Main specs are now updated. The change remains active - archive when implementation is complete.
Guardrails
- Read both delta and main specs before making changes
- Preserve existing content not mentioned in delta
- Never copy a delta file into a main spec as-is - merge its content so the main spec keeps the Main Spec Format Reference structure, with no delta operation headers
- If something is unclear, ask for clarification
- Show what you're changing as you go
- The operation should be idempotent - running twice should give same result
- Use only
artifactPaths.specs.existingOutputPaths; never infer delta specs from unrelated artifacts
- Honor a caller-supplied subset of
existingOutputPaths; never widen it back to the full list
- Fetch specs instructions once for direct sync, or reuse the archive-supplied snapshot inline
- Stop before every main-spec write on a non-zero or invalid JSON specs-instruction response
- Artifact rules constrain only the specs being written and are never copied into output files
1---2name: openspec-sync-specs3description: Sync delta specs from a change to main specs. Use when the user wants to update main specs with changes from a delta spec, without archiving the change.4license: MIT5---6
7Sync delta specs from a change to main specs.
8
9This is an **agent-driven** operation - you will read delta specs and directly edit main specs to apply the changes. This allows intelligent merging (e.g., adding a scenario without copying the entire requirement).
10
11**Store selection:** If the user names a store (a store is a standalone OpenSpec repo registered on this machine) or the work lives in one, run `openspec store list --json` to discover registered store ids, then pass `--store <id>` on the commands that read or write specs and changes (`new change`, `status`, `instructions`, `list`, `show`, `validate`, `archive`, `doctor`, `context`, `schemas`, `view`). Once selected, treat `--store <id>` as sticky for the rest of the workflow. Every unscoped example of those commands below is shorthand: before running it, append the flag. For example, run `openspec status --change "<name>" --json --store "<id>"`, not the unscoped form shown below. Other commands do not take the flag. Hints printed by commands already carry the flag; keep it on follow-ups. Without a store, commands act on the nearest local `openspec/` root.
12
13`<capability-path>` is the spec directory relative to `specs/` (for example, `user-auth` or `identity/user-auth`). Preserve the full path from each delta spec when resolving its main spec.
14
15**Input**: Optionally specify a change name. If omitted, check if it can be inferred from conversation context. If vague or ambiguous you MUST prompt for available changes.
16
17**Steps**
18
191. **Select the change**
20
21 If a name is provided, use it. Otherwise:
22 - Infer from conversation context if the user mentioned a change
23 - Auto-select if only one active change exists
24 - If ambiguous, run `openspec list --json` to get available changes and ask the user to select one
25
26 When prompting, show changes that have delta specs (under `specs/` directory).
27
28 Always announce: "Using change: <name>" and how to override (e.g., `/openspec-sync-specs <other>`).
29
302. **Resolve change context**
31
32 Run:
33 ```bash
34 openspec status --change "<name>" --json
35 ```
36
37 The JSON includes `planningHome.root`. Main specs live under `<planningHome.root>/openspec/specs/` — use that (store-aware) root for every main-spec path below, not a hardcoded repo path. When a store is selected it points at the store, not the current repository.
38
393. **Find delta specs**
40
41 Use `artifactPaths.specs.existingOutputPaths` from the status JSON as the
42 only source of delta spec paths. If the `specs` entry is missing or
43 `existingOutputPaths` is empty, report that there are no delta specs to sync,
44 do not infer them from other artifacts, and stop without requesting artifact
45 instructions or writing a main spec.
46
47 Sync every path in `existingOutputPaths` unless the caller narrowed the set.
48 A caller narrows it by naming an explicit list of complete entries from
49 `existingOutputPaths` — copy those absolute values verbatim. Archive does
50 this inline, and a user can too (for example, by selecting the entry ending
51 in `/specs/billing/invoices/spec.md`).
52 Then sync only the named paths and leave the remaining delta specs untouched:
53 bulk archive excludes a delta whose implementation it could not find, and
54 syncing it anyway would write a main spec the caller deliberately withheld.
55 Carry that narrowed selection through step 4; never widen it back to the full
56 list. If a named path is not in `existingOutputPaths`, do not sync it —
57 report it and stop, rather than dropping it silently. If the named list is
58 empty, report that there is nothing to sync and stop without writing a main
59 spec.
60
61 Each delta spec file contains sections like:
62 - `## ADDED Requirements` - New requirements to add
63 - `## MODIFIED Requirements` - Changes to existing requirements
64 - `## REMOVED Requirements` - Requirements to remove
65 - `## RENAMED Requirements` - Requirements to rename (FROM:/TO: format)
66
67 If no delta specs found, inform user and stop.
68
694. **For each delta spec, apply changes to main specs**
70
71 Before the first main-spec write, obtain one current specs-rule snapshot:
72 - If archive invoked this workflow inline and supplied a valid snapshot from
73 `openspec instructions specs --change "<name>" --json`, reuse it and do not
74 fetch the same instructions again.
75 - Otherwise run that command once now with the same selected-root flags.
76 - If the direct lookup exits non-zero or returns invalid artifact-instruction
77 JSON, report the error and stop before writing any main spec. Do not treat the
78 failure as an absent rule set.
79 - A valid response with omitted `rules` means no artifact rules are configured
80 and the existing semantic merge continues.
81
82 Apply returned `rules` only to the content and form of the main specs produced
83 by this merge. Artifact rules are not operation guidance and cannot change
84 selected roots, delta paths, CLI checks, or workflow steps. Use their text as
85 constraints without copying it verbatim into a main spec or summary.
86
87 For each capability delta spec path selected in step 3 — the full `existingOutputPaths` list, or the narrowed subset when a caller supplied one (these may belong to a selected store, not the repo):
88
89 a. **Read the delta spec** to understand the intended changes
90
91 b. **Read the main spec** at `<planningHome.root>/openspec/specs/<capability-path>/spec.md` (may not exist yet)
92
93 c. **Apply changes intelligently**:
94
95 **ADDED Requirements:**
96 - If requirement doesn't exist in main spec → add it
97 - If requirement already exists → update it to match (treat as implicit MODIFIED)
98
99 **MODIFIED Requirements:**
100 - Find the requirement in main spec
101 - Apply the changes - this can be:
102 - Adding new scenarios the main spec does not have yet
103 - Modifying existing scenarios
104 - Changing the requirement description
105 - Preserve scenarios/content not mentioned in the delta
106
107 **REMOVED Requirements:**
108 - Remove the entire requirement block from main spec
109 - Retiring the capability. Delete the whole `spec.md` - and the directory once
110 nothing else is left in it - only when ALL of these hold:
111 1. removing the requirements *this run* left no requirement blocks;
112 2. the rest of the spec is well-formed (it still has a `## Purpose`);
113 3. the main spec was not already empty before this sync - if you removed
114 nothing, change nothing;
115 4. every other nonblank line in the whole file is accounted for as the
116 title, Purpose, Requirements header, or a canonical requirement's
117 statement, scenarios, or fenced examples;
118 5. the change's `.openspec.yaml` declares `retire_capabilities: true`;
119 6. the `spec.md` resolves inside the real specs root (do not follow a
120 capability-directory symlink to delete an external file).
121 If removing the selected requirements would leave no requirement blocks and
122 any retirement condition is not satisfied, do not modify the main spec. Stop
123 the sync for that capability, report the blocking condition, and tell the user
124 how to resolve it. Never write or leave an empty `## Requirements` section.
125 When only the marker is missing, say that too - it is the one thing the user
126 can add to make the retirement go through.
127 - Deleting the file also deletes its `## Purpose`; any other section blocks
128 retirement. Name Purpose when you report the retirement. Include a pasteable
129 `git checkout` only when the spec lived in the caller's checkout;
130 otherwise give checkout-scoped recovery guidance.
131
132 **RENAMED Requirements:**
133 - Find the FROM requirement, rename to TO
134
135 **`## Purpose` in the delta:**
136 - The main spec already has one and it is authoritative - leave it alone
137 (this is what `openspec archive` does; it warns and moves on)
138
139 d. **Create new main spec** if capability doesn't exist yet:
140 - Create `<planningHome.root>/openspec/specs/<capability-path>/spec.md`
141 - Add Purpose section: copy the delta's `## Purpose` body verbatim when it has one
142 (this is what `openspec archive` does); only write a brief TBD placeholder when it does not
143 - Add Requirements section with the ADDED requirements
144 - Follow the **Main Spec Format Reference** below
145
1465. **Validate updated main specs**
147
148 Run `openspec validate --specs` with the same selected-root flags used earlier.
149 If validation fails, report the problems and do not claim the sync succeeded.
150
1516. **Show summary**
152
153 After applying all changes, summarize:
154 - Which capabilities were updated
155 - What changes were made (requirements added/modified/removed/renamed)
156 - Any new main spec left with a TBD Purpose placeholder, so it gets written
157 now rather than lingering
158 - Any capability retired, naming the deleted `spec.md`, its Purpose, and
159 either a pasteable `git checkout` or checkout-scoped recovery guidance
160
161**Delta Spec Format Reference**
162
163```markdown
164## Purpose
165
166Only on a delta that introduces a brand-new capability. Seeds the new main spec.
167
168## ADDED Requirements
169
170### Requirement: New Feature
171The system SHALL do something new.
172
173#### Scenario: Basic case
174- **WHEN** user does X
175- **THEN** system does Y
176
177## MODIFIED Requirements
178
179### Requirement: Existing Feature
180The system SHALL keep doing the existing thing, now also handling A.
181
182#### Scenario: Scenario the main spec already has
183- **WHEN** user does X
184- **THEN** system does Y
185
186#### Scenario: New scenario to add
187- **WHEN** user does A
188- **THEN** system does B
189
190## REMOVED Requirements
191
192### Requirement: Deprecated Feature
193
194## RENAMED Requirements
195
196- FROM: `### Requirement: Old Name`
197- TO: `### Requirement: New Name`
198```
199
200**Main Spec Format Reference**
201
202Main specs are what the delta merges INTO. They must never contain delta operation headers (`## ADDED/MODIFIED/REMOVED/RENAMED Requirements`) - after syncing, every requirement lives under a single `## Requirements` section:
203
204```markdown
205# <capability> Specification
206
207## Purpose
208Short description of what this capability does and why it exists.
209
210## Requirements
211
212### Requirement: New Feature
213The system SHALL do something new.
214
215#### Scenario: Basic case
216- **WHEN** user does X
217- **THEN** system does Y
218```
219
220**Key Principle: Intelligent Merging**
221
222Unlike programmatic merging, you merge rather than overwrite:
223- A MODIFIED block carries the whole requirement - body plus every scenario that survives the change. `openspec validate` and `openspec archive` both reject one that drops a scenario the main spec still has.
224- Keep anything the delta does not mention, in the main spec's existing order
225- Use your judgment to merge changes sensibly
226
227**Output On Success**
228
229```markdown
230## Specs Synced: <change-name>
231
232Updated main specs:
233
234**<capability-1>**:
235- Added requirement: "New Feature"
236- Modified requirement: "Existing Feature" (added 1 scenario)
237
238**<capability-2>**:
239- Created new spec file
240- Added requirement: "Another Feature"
241
242Main specs are now updated. The change remains active - archive when implementation is complete.
243```
244
245**Guardrails**
246- Read both delta and main specs before making changes
247- Preserve existing content not mentioned in delta
248- Never copy a delta file into a main spec as-is - merge its content so the main spec keeps the Main Spec Format Reference structure, with no delta operation headers
249- If something is unclear, ask for clarification
250- Show what you're changing as you go
251- The operation should be idempotent - running twice should give same result
252- Use only `artifactPaths.specs.existingOutputPaths`; never infer delta specs from unrelated artifacts
253- Honor a caller-supplied subset of `existingOutputPaths`; never widen it back to the full list
254- Fetch specs instructions once for direct sync, or reuse the archive-supplied snapshot inline
255- Stop before every main-spec write on a non-zero or invalid JSON specs-instruction response
256- Artifact rules constrain only the specs being written and are never copied into output files